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What is percutaneous tumour ablation?

Percutaneous tumour ablation refers to a range of techniques which destroy tumour tissue via needles placed through the skin. Some techniques use chemical agents (such as absolute ethanol), while others use physical agents, which may be thermal (using heat) or non-thermal. Thermal ablation techniques destroy tumours by using different kinds of applicators to freeze the tumour (called cryoablation) or to heat the tumour, such as radiofrequency ablation, laser ablation, microwave ablation and high-intensity focused ultrasound (HIFU).

Non-thermal ablation techniques use other sources of energy to achieve tumour destruction. Coblation uses an electrical plasma field to disintegrate the tissue by rupturing the bonds between the molecules which make up the tumour tissue. Irreversible electroporation uses high voltage electric shocks to pierce the cell membranes and cause cell death.

How does the procedure work?

The procedure will be carried out using image guidance, such as ultrasound, CT or MRI, to control the insertion of the devices and the energy deposition. You will be anaesthetised for the procedure. For most ablation procedures, the interventional radiologist will insert one or more needles or applicators into your tumour to deliver the chemical agent or physical energy.

Why perform it?

The goal of tumour ablation is to destroy the tumour without using surgery. Whether you are suitable for this procedure depends on the size and location of the tumour as well as your clinical situation.

What are the risks?

The insertion of the needle or applicator may cause bleeding or puncture surrounding organs. Another risk is the accidental leakage of the chemical agent or uncontrolled depositing of radiation energy, which may cause serious damage to the surrounding tissues.

Bibliography

1. Crocetti L, de Baere T, Lencioni R. Quality improvement guidelines for radiofrequency ablation of liver tumours. Cardiovasc Intervent Radiol. 2010 Feb; 33(1):11-7.

What is angiography?

Angiography (also known as arteriography) is a medical imaging technique which is used to visualise the inside of your blood vessels, particularly the arteries.

The procedure is carried out by an interventional radiologist, who will inject a radiopaque contrast agent into your blood vessel. This is a substance which will make your blood vessels show up more clearly under imaging. The interventional radiologist will use fluoroscopy for image guidance.

A diagnostic arteriogram is a procedure which involves inserting a needle or catheter into an artery, followed by injection of a contrast agent and then observing the area via imaging.

How does the procedure work?

You will have a local anaesthetic for the procedure. The interventional radiologist will insert a catheter and guidewire into the affected area and will inject the contrast agent so he can visualise the anatomy of your artery and the disease. Occasionally, the interventional radiologist will need to access the artery through your common femoral artery (CFA), which is in your thigh.

Why perform it?

You may be advised to have a diagnostic angiography if your doctor suspects that you have vascular disease, particularly acute pulmonary embolus (a mass which moves around your body and may clog an artery), and other tests have been unclear. A diagnostic angiography can also be used to diagnose and localise a hypervascular tumour (a tumour with a large number of arterial blood vessels).

A further possible reason to have an angiography is as a pre-operative procedure, meaning your doctor would like a more detailed knowledge of your anatomy, as this knowledge is beneficial for procedures such as revascularisation (restoring blood to an area with a restricted blood supply), local tumour resection (surgically removing a tumour) and organ transplantation.

A diagnostic angiography also aids with diagnosis and treatment of post-operative or traumatic complications. It can also be used during procedures such as thrombolysis, angioplasty, stenting and embolisation as it gives the interventional radiologist performing the procedure a clearer view of what they are doing.

What are the risks?

There are a number of possible risks. You may have bruising, a pseudoaneurysm (when a bruise forms outside an artery wall) or a blood clot.

Systemic complications are complications which affect the rest of your organ systems. These occur in less than 5% of cases, and include nausea, vomiting and fainting. In less than 1 in 1000 cases, patients experience a life-threatening reaction to the contrast agent. Mortality associated with the contrast injection occurs in less than 1 in 120,000 cases and this is usually related to underlying factors, such as severe congestive heart failure, major trauma and general weakness.

Individuals react to the contrast agent in different ways, and it is possible you will experience hives, puffy eyes or wheezing, though these complications occur in fewer than 3% of angiographic procedures. Most reactions are mild, with more than half not needing any therapy at all and less than 1% requiring hospitalisation.

When less strong agents are used, there are fewer reactions. Agents that are more diluted tend to be used in patients with a history of reacting to contrast agents or patients who have more than one other major risk factor.

Bibliography

1. Singh H, Cardella JF, Cole PE, Grassi CJ, McCowan TC, Swan TL, Sacks D and Lewis CA. Quality Improvement Guidelines for Diagnostic Arteriography. J Vasc Interv Radiol 2003; 14: S283-S288.
2. Martin LG, Rundback JH, Wallace MJ, Cardella JF, Angle JF, Kundu S, Miller DL and Wojak JC. Quality Improvement Guidelines for Angiography, Angioplasty, and Stent Placement for the Diagnosis and Treatment of Renal Artery Stenosis in Adults. J Vasc Interv Radiol 2010; 21:421-430.
3. Connors JJ 3rd, Sacks D, Furlan AJ, Selman WR, Russell EJ, Stieg PE and Hadley MN for the NeuroVascular Coalition Writing Group. Training, Competency, and Credentialing Standards for Diagnostic Cervicocerebral Angiography, Carotid Stenting, and Cerebrovascular Intervention. J Vasc Interv Radiol 2004; 15:1347-1356.

What is angioplasty and stenting?

The arteries supplying your head, heart, kidneys and legs may become blocked over time because of smoking, high cholesterol, high blood pressure, diabetes and obesity. These can cause a progressive hardening and occlusion of the vessels (also known as arteriosclerosis). Arteriosclerosis reduces blood flow to your organs as a result of the narrowed or obstructed arteries.

Interventional radiologists are recognised experts in vascular diseases, who can use a technique involving angioplasty and stenting to restore blood flow to the brain, kidneys and legs.

Angioplasty involves the mechanical dilatation of any narrowed or occluded vessel by means of a balloon catheter and a metal stent if necessary. Balloon catheters are tiny empty balloons which are gently inflated to expand the area. A stent is a metal mesh tube that is inserted over a metallic guidewire and positioned at the point of the stenosis or occlusion. Metal stents are permanent implants and act as mechanical scaffolds to support the vessel wall and keep the vessel open.

How does the procedure work?

You will have a local anaesthetic for the procedure. The angioplasty and stenting procedure will last around an hour and tends to be performed as an out-patient procedure, though in some cases patients are admitted to hospital overnight afterwards.

The interventional radiologist will puncture an artery in your thigh with a small needle and will then thread a combination of plastic tubes (called sheaths and catheters) into your arteries. Throughout the procedure, the interventional radiologist will use imaging for guidance. A balloon catheter will be inflated across the narrowed or obstructed part of the vessel; you may experience some discomfort at this point. In some cases, the balloon angioplasty is enough to keep the vessel open, but in other cases the vessel needs more support, so a stent is placed. This means the interventional radiologist will put a stent into the vessel to ensure it stays open.

Your vital signs will be monitored during and after the procedure, and you may be able to eat a light meal later the same day.

Why perform it?

This procedure may be beneficial for you if you suffer from leg pain when walking (intermittent claudication) or if you have a restricted blood supply in your legs (leg ischaemia) as a result of diabetes. The angioplasty and stenting procedure can also be a treatment for peripheral arterial disease and for narrowed or blocked arteries in your kidneys.

Angioplasty and stenting is a way to restore blood flow, relieve pain caused by restricted blood flow, improve kidney function and protect the brain from strokes.

What are the risks?

The success rate of the procedure is usually around 90-95%, though it varies according to the extent and complexity of the blockages in the artery. The majority of patients experience significant clinical improvement, meaning that their pain decreases and any wounds in the area heal better.

In around 10-15% of cases (the rate depends on the location and particular structure of the artery), the affected artery becomes blocked again, known as restenosis. If this happens to you, your symptoms will return and you will need to be treated again.

Minor complications are unusual but include bleeding, bruising and infection. In rare cases, patients have an abdominal haemorrhage, which requires a stay in hospital and patients may need blood transfusions. It is possible that the artery will be damaged by the balloon, causing the vessel to rupture, in which case the interventional radiologist will place a covered stent in the vessel to control any bleeding. The balloon inflation may cause small fragments from the blockage to break off and block other smaller vessels, causing the blood flow to be restricted even more. There is a very low risk of losing a limb or stroke, depending on the location of the artery on which the procedure is carried out.

Although the interventional radiologist will do all they can do minimise the risk of an allergic reaction, there is a risk of a reaction to the dye used in the imaging technique.

Bibliography

1. Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG; TASC II Working Group, Bell K, Caporusso J, Durand-Zaleski I, Komori K, Lammer J, Liapis C, Novo S, Razavi M, Robbs J, Schaper N, Shigematsu H, Sapoval M, White C, White J, Clement D, Creager M, Jaff M, Mohler E 3rd, Rutherford RB, Sheehan P, Sillesen H, Rosenfield K. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). Eur J Vasc Endovasc Surg. 2007; 33 Suppl 1:S1-75.
2. Rooke TW, Hirsch AT, Misra S, Sidawy AN, Beckman JA, Findeiss L, Golzarian J, Gornik HL, Jaff MR, Moneta GL, Olin JW, Stanley JC, White CJ, White JV, Zierler RE; American College of Cardiology Foundation Task Force; American Heart Association Task Force. Management of patients with peripheral artery disease (compilation of 2005 and 2011 ACCF/AHA Guideline Recommendations): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013 Apr 9; 61(14):1555-70. doi: 10.1016/j.jacc.2013.01.004.

What is aspiration?

Aspiration is the image-guided puncture of a cystic lesion (such as a cyst, an abscess or bruising) or solid lesion (a growth) in order to remove a fluid or tissue sample with a suction needle. The hollow aspiration needles come in different sizes and lengths.

How does the procedure work?

If you are on any medication that prevents blood clotting, you should stop taking it before the procedure, if possible.

You should not eat anything for at least four hours before the procedure. You may be asked to fast for longer, depending on the puncture and whether the procedure is particularly complicated.

The interventional radiologist may use one of a number of image guidance techniques to plan and monitor the placement of the needle during the aspiration procedure, including ultrasound, CT, MRI and fluoroscopy. You will lie down for the procedure – the exact position you will be asked to lie in depends on the access route that the interventional radiologist will use to safely approach the lesion.

Aspiration is usually performed under local anaesthesia. You may be asked to take antibiotics beforehand to reduce the risk of infection, but this is uncommon.

The procedure will be carried out in a sterile and safe environment. The interventional radiologist will use image guidance to insert a needle until the needle tip is inside the lesion. The interventional radiologist will then insert a syringe to remove the sample or cyst.

Aspiration can be performed as an in-patient or out-patient procedure. The puncture site will be monitored for 2-4 hours to check for bleeding. You may experience some mild discomfort at the puncture site during the first few hours following the procedure.

Why perform it?

You may be recommended to have an aspiration procedure for diagnostic reasons (to provide information on the nature of the lesion) or for therapeutic purposes, such as removal of the fluid collection or cyst. Aspiration is sometimes preferred over drainage of small abscesses (less than 3-4 cm) for which a drainage catheter would be unsuitable.

Aspiration may not be the best option for you if you have a blood clotting disorder or there is no safe access route.

The technical success rate of this procedure is very high, though the clinical success rate can vary depending on the location and nature of the lesion, as well as whether the aspiration procedure is diagnostic or therapeutic.

What are the risks?

Fine needles are used for the procedure, making the complication rate very low. The most common side effects are bruising, infection, and, in the case of lung aspiration procedures, pneumothorax (the collection of air in the space between the chest wall and the lung).

If the aspiration was used to treat an abscess, you may experience procedure-related sepsis (widespread inflammation in the body), but the risk of this is lower than with drainage procedures.

Bibliography

1. Layfield LJ, Gopez EV. Percutaneous image-guided fine needle aspiration of peritoneal lesions. Diagn Cytopathol 2003; 28(1):6-12.
2. Abusedera MA, Khalil M, Ali AMA, Hassan AE. Percutaneous image-guided aspiration versus catheter drainage of abdominal and pelvic collections. Egypt J Radiol Nuclear Med 2013; 44(2): 223-230.
3. Kerimaa P, Marttila A, Hyvönen P, et al. MRI-guided biopsy and fine needle aspiration biopsy (FNAB) in the diagnosis of musculoskeletal lesions. Eur J Radiol 2013.

Portal hypertension refers to high blood pressure in the liver. One of the major possible complications of portal hypertension is gastric variceal bleeding. Varices are dilated vessels which may rupture, causing variceal bleeding. Gastric variceal bleeding describes the bleeding that occurs when dilated vessels in the stomach rupture, and is associated with high morbidity and mortality rates.

BRTO is a minimally invasive technique that is used to treat gastric variceal bleeding. The procedure involves blocking the dilated vessels, reducing the risk of rupture. It can be used in addition to or as an alternative to TIPS, which is the primary treatment for gastric varices. TIPS aims to relieve the pressure on the dilated vessels by creating new connections between blood vessels in the liver using a shunt.

How does the procedure work?

The interventional radiologist will insert a balloon catheter (a thin, flexible tube with a tiny balloon at one end) through a vein in your thigh or neck and guide the catheter to the liver using fluoroscopy for guidance. The catheter is then directed to the gastrorenal or gastrocaval shunt and the balloon is expanded to block the shunt.

The interventional radiologist will then perform a venography, which is a type of imaging technique in which X-rays are used to see the vessels clearly. This will allow the interventional radiologist to confirm exactly which vessels need to be treated and if there are any other abnormal or dilated vessels which have not previously been identified. A medication will then be injected into the dilated vessels through the catheter, until they are completely filled. This medication will remain in the vessel for a short period of time, and will then be removed under fluoroscopy.

Another venography will then be performed, to confirm that the blood flow in the shunt has stopped. Finally, the balloon will be deflated and the interventional radiologist will withdraw the catheter.

Why perform it?

You may be advised to undergo this procedure if you are at risk of or already have gastric variceal bleeding and hepatic encephalopathy as well as a gastrorenal shunt. Hepatic encephalopathy refers to the worsening of brain function that is caused by a damaged liver.

Although TIPS has been considered the standard therapy for gastric varices that have been unresponsive to other treatments, recent reports have stated that BTRO is a less invasive and more effective way to manage varices than shunt surgery or TIPS. TIPS does not always cause the disappearance of gastric varices, while BRTO can in most cases completely destroy these vessels.

BRTO has tended to be used to prevent gastric variceal bleeding. It is also an effective therapy for sclerosis (narrowing) of new portosystemic shunts with the additional complication of hepatic encephalopathy. One of the greatest advantages of BRTO is its preservation of liver function. Moreover, the increase of blood flow in BRTO can also improve liver function in cases where the patient has cirrhosis (scarring of the liver).

What are the risks?

Procedure-related complications are minor and include bleeding and infection. In rare cases, the blockage of the blood to the gastric varices can further increase the pressure on the liver, causing damage to the liver.

The most serious complications of the procedure, however, are related to the medication used to block the vessels, which is called ethanolamine oleate. Inflow of a relatively large amount of ethanolamine oleate can lead to serious complications. These complications include pulmonary embolism (blockage in a lung’s main artery), fluid in or around the lungs, hypersensitivity, fever, problems with blood flow to the heart and the formation of small blood clots in vessels throughout the body. Ethanolamine oleate also causes haemolysis, which is the rupturing of red blood cells. To prevent this from occurring, only a low dose of the medication is used.

Bibliography

1. Kitamoto M, Imamura M, Kamada K, et al. Balloon-occluded retrograde transvenous obliteration of gastric fundal varices with hemorrhage. AJR Am J Roentgenol. 2002;178:1167–1174.
2. Wael E. A. Saad, M.D., F.S.I.R.1 and Saher S. Sabri, M.D Balloon-occluded Retrograde Transvenous Obliteration (BRTO): Technical Results and OutcomesSemin Intervent Radiol. Sep 2011; 28(3): 333–338.

What are biliary procedures?

Percutaneous transhepatic biliary drainage (PTCD) is the placement of a drain into bile ducts using needles inserted through the skin. The procedure can be used to treat cholestasis (where the bile cannot flow from the liver to the small intestine), which may be a result of a narrowing or blockage in the bile ducts or of a bile leakage after an operation.

Biliary stenting is performed after biliary drainage if the blockage is malignant (cancerous) to keep the bile duct open and to allow the drain used in PTCD to be removed. This involves putting a stent (a mesh metal tube) into the bile duct, which then functions as a supportive skeleton to prevent the duct from closing.

Biliary stone extraction is carried out using percutaneous access to the biliary tree (also known as the biliary tract, this is the path by which bile travels from the liver to the small intestine). Stones can be removed using a tiny basket or with a grasping device. Small and medium-sized stones can be pushed into the first part of the small intestine using a tiny balloon. If the stones are larger than 5 mm, a tiny balloon is used to dilate the entrance to the small intestine.

How does the procedure work?

Puncturing the bile duct is usually performed under sedation and local anaesthesia, though in rare cases and depending on the patient’s underlying condition and age, the procedure may be carried out under general anaesthesia.

You will be given antibiotics beforehand to prevent infection. The procedure will be carried out in a sterile room while you lie on your back. The interventional radiologist will perform the procedure under X-ray guidance, though sometimes ultrasound is used in addition to fluoroscopy to confirm the direction for the puncture.

The interventional radiologist will pass a small needle through your skin into either your left or your right liver lobe. If it is the right liver lobe which is punctured, this will be between your ribs and in the middle of your side. If it is your left liver lobe which is punctured, the interventional radiologist will choose an entry site below the tip of your breastbone.

As the needle is withdrawn, the interventional radiologist will gently inject a diluted contrast agent, a substance which makes the area show up better under imaging. This means that, when the needle enters the bile duct, the tubular structure is more clearly visible under imaging. The interventional radiologist will then insert a guidewire into the bile duct, which is followed by a catheter. The guidewire and catheter are used together to move past the blockage and reach the intestine.

Once the interventional radiologist has removed this catheter, they will dilate the blocked liver tract so that the drainage catheter can be placed. A drainage catheter has multiple holes in its side which are used to drain the bile in two directions, outwards into a bag and inwards into the intestine. The bag will be attached to the skin and left in place for a few days until the biliary tract has decompressed. During the period when the bag is attached, the catheter is flushed 2-3 times a day with sodium chloride to keep the side-holes open.

Why perform it?

If you are unsuitable for endoscopic procedures, PTCD is a possible alternative for you. It can be used to decompress the biliary ducts if they are blocked by a mass lesion or a stone, or to bridge a hole if you experience bile leakage.

What are the risks?

One of the most common complications is bleeding into the biliary tract, usually from a vein. This normally does not need treatment as it heals by itself. A less frequent complication is major bleeding requiring a blood infusion or further interventions, such as surgery or embolisation of the vessels.

If you have a biliary infection, the PTCD procedure may cause fever, chills and septicaemia. A further risk is the possibility that the areas around the tract will be punctured during the procedure, such as the gallbladder or bowel.

Bibliography

1. Saad WEA, Wallace MJ, Wojak JC, Kundu S, Cardella JF. Quality improved guidelines for percutaneous transhepatic cholangiography, biliary drainage, and percutaneous cholecystostomy. J Vasc Interv Radiol 2010; 21:789-95.
2. Krokidis M, Hatzidakis A. Percutaneous Minimally Invasive Treatment of Malignant Biliary strictures: Current status Cardiovasc Intervent Radiol 2013 Jul 13.

What is an image-guided biopsy?

An image-guided biopsy aims to provide diagnostic information by obtaining a sample of tissue from under the skin using imaging to navigate. The interventional radiologist will perform this procedure using special cutting needles which are available in a variety of diameters and lengths. The tissue sampled will usually be examined under a microscope by a pathologist and can also be analysed chemically.

How does the procedure work?

If you are on any medication that prevents blood clotting, you will stop taking it before the procedure, if possible.

You should not eat anything for at least four hours before the procedure starts. You may be asked to fast for longer, depending on the puncture and the complexity of your particular case. Before the procedure, the interventional radiologist will usually place a needle in your vein to make access easier during the procedure.

The interventional radiologist may use one of a number of image-guidance techniques to plan and monitor the placement of the needle during the aspiration procedure, including ultrasound, CT, MRI and fluoroscopy. This depends on the location and nature of the lesion.

Most biopsy procedures are performed under local anaesthesia or conscious sedation, so you will be awake but feel no pain. You may be asked to take antibiotics beforehand to reduce the risk of infection, but this is uncommon. You will lie down for the procedure – the exact position you will be asked to lie in depends on the access route that the interventional radiologist will use to safely approach the lesion.

The procedure will be carried out in a sterile and safe environment. The interventional radiologist will choose which type of needle to use according to the organ and tissue type which needs to be sampled, such as bone, soft tissue, lung, etc. The interventional radiologist will insert the needle and will guide it using imaging until the needle tip can be seen inside the lesion.

An image-guided biopsy can be performed as an in-patient or out-patient procedure. The site of the puncture and your vital signs will be monitored for 4-6 hours following the procedure. You will experience some mild discomfort around the puncture site during this time. If you undergo a lung biopsy, you will be given a chest X-ray 6-8 hours after the procedure to ensure that no air has been trapped in the cavity between your chest wall and your lungs. In most cases, you will be allowed to drink water a few hours after the biopsy procedure.

Why perform it?

If you have a lesion and your doctor needs further information to make a diagnosis, you may be referred for an image-guided biopsy.

There are a number of factors which may make the procedure unsuitable for you, including if you have a blood clotting disorder, if there is no safe route for the interventional radiologist to access the lesion, or if you have already been diagnosed using other procedures, such as diagnostic imaging.

The success rate of the biopsy procedure can vary depending on the location of the lesion and the type of needle used. Image guidance is used to confirm that the needle is placed correctly inside the lesion and to help avoid complications.

What are the risks?

If the interventional radiologist uses a small bone needle, the complication rate is low. The most common complications are bruising and infection. If you have had a lung biopsy there is a risk of pneumothorax, which means that air fills the gap between the lungs and the chest wall.

Bibliography

1. Gupta S. Role of image-guided percutaneous needle biopsy in cancer staging. Seminars in Roentgenol 2006; 41(2): 78-90.
2. Kerimaa P, Marttila A, Hyvönen P, et al. MRI-guided biopsy and fine needle aspiration biopsy (FNAB) in the diagnosis of musculoskeletal lesions. Eur J Radiol 2013.
3. Klein JS, Zarka MA. Transthoracic needle biopsy: an overview. J Thorac Imaging 1997; 12(4):232-49.

What is bone augmentation?

Bone augmentation techniques aim to stabilise a weakened or a fractured bone. These minimally invasive techniques include injection of bone cement designed for this purpose, the insertion of metallic rods or screws, or a combination of both techniques, depending on the location and on the type of fracture.

How does the procedure work?

The interventional radiologist will use image guidance to precisely insert the devices used to reinforce a weakened or fractured bone.

Why perform it?

Percutaneous image-guided bone fixation is performed to stabilise a weakened bone. The procedure is a minimally invasive alternative to conventional surgery and it may be recommended to treat a range of conditions, including bone metastases, osteoporotic fractures or fractures caused by trauma.

What are the risks?

Placing needles inside bone carries the risk of bleeding and infection. In rare cases, the surrounding structures such as nerves or vessels are damaged. Occasionally, optimal stabilisation cannot be achieved, which can cause a delayed fracture to another bone. You are especially at risk for this if you have advanced bone cancer.

Bibliography

1. Huegli RW, Messmer P, Jacob AL, Regazzoni P, Styger S, Gross T. Delayed union of a sacral fracture: percutaneous navigated autologous cancellous bone grafting and screw fixation. Cardiovasc Intervent Radiol. 2003 Sep-Oct; 26(5):502-5.
2. Trumm CG, Rubenbauer B, Piltz S, Reiser MF, Hoffmann RT. Screw placement and osteoplasty under computed tomographic-fluoroscopic guidance in a case of advanced metastatic destruction of the iliosacral joint. Cardiovasc Intervent Radiol. 2011 Feb; 34 Suppl 2:S288-93.
3. Deschamps F, Farouil G, Hakime A, Teriitehau C, Barah A, de Baere T. Percutaneous stabilization of impending pathological fracture of the proximal femur. Cardiovasc Intervent Radiol. 2012 Dec; 35(6):1428-32.

What is brachytherapy?

Brachytherapy is a form of therapy used to treat cancer by placing radiation inside the body.

How does the procedure work?

The interventional radiologist will place small metal beads or wires into the cancerous tissue, usually using radiological imaging as a guide. These emit high energy radiation, which then spreads a short distance from this source into the surrounding tissue containing the tumour, whilst limiting radiation to the non-cancerous, normal tissues that are further away. The radiation kills the tumour cells.

Why perform it?

The procedure is performed to cure cancer or to limit its progression. It may be used alone or conjunction with other therapies including chemotherapy and surgery. It has been applied to a range of cancers including, but not limited to, prostate, cervix, liver, rectum and breast cancer.

What are the risks?

Placing the radiation source carries the risk of bleeding and infection. There is a risk of the radiation killing normal, non-cancerous cells. You may experience pain in the area treated.

Bibliography

1. Collettini F, Golenia M, et al. Percutaneous computed tomography-guided high-dose-rate brachytherapy ablation of breast cancer liver metastases: initial experience with 80 lesions. J Vasc Interv Radiol 2012 23(5): 618-626.
2. Luo J, Yan Z, et al. Endovascular placement of iodine-125 seed strand and stent combined with chemoembolization for treatment of hepatocellular carcinoma with tumor thrombus in main portal vein. J Vasc Interv Radiol 2011 22(4): 479-489.

What is tracheobronchial stenting?

Your airway system consists of the trachea, which is then divided into different sections, called the main stem and segmental bronchi, which supply both your lungs. Diseases which block the airways are very dangerous, as they may cause the lungs to collapse and prevent the patient from inhaling enough air, causing death.

A stent is a metal mesh tube that is inserted over a guidewire and placed in a vessel in order to keep it clear. Tracheobronchial stenting refers to the placing of a stent in a patient’s airways to treat or prevent restricted airflow. The procedure is minimally invasive and is most often used to relieve symptoms caused by cancerous tumours blocking airways.

Why perform it?

If you have a cancerous growth in your trachea or bronchi which cannot be operated on and is affecting your breathing, having a stent placed may relieve your breathlessness while you undergo chemotherapy and/or radiotherapy.

In some cases, a stent is placed to treat fistulas (holes) that have developed in the airway system or to treat blockages in the airway that are not cancerous. If the patient is a child, the use of biodegradable stents, which are absorbed over time, is recommended.

How does the procedure work?

You will have a general anaesthetic for the procedure, which will be carried out in an operating theatre by a team of interventional radiologists and surgeons. The doctors will use fluoroscopy and a bronchoscope (a tiny camera inserted into your body on a tube) for guidance.

An interventional radiologist will thread a guidewire into your airway system so that the stent can be guided to the correct location. Once placed in the affected area, the stent will expand, clearing the airway.

An oncologist may take a tissue sample before the stent is placed, if this would be beneficial in planning your optimal treatment.

In most cases, patients stay in hospital overnight, and you will be discharged from hospital once you have had a consultation with the thoracic and oncology teams who will provide your follow-up care.

What are the risks?

The majority of cases (over 95%) are successful, and most patients (70-80%) see significant clinical improvement 24-48 hours after the procedure. In 10-20% of cases, the stent migrates, meaning it moves to another part of the body. If this occurs, the stent will be removed and replaced with a new stent.

Other possible complications include bleeding, chest infection, temporary chest pain and the risk of the airways reacting to the stents, which can cause spasm and breathlessness.

Bibliography

1. Inchingolo R, Sabharwal T, Spiliopoulos S, Krokidis M, Dourado R, Ahmed I, King J, Adam A. Tracheobronchial stenting for malignant airway disease: long-term outcomes from a single-center study. Am J Hosp Palliat Care. 2013 Nov; 30(7):683-9. doi: 10.1177/1049909112462861.
2. Du Rand IA, Barber PV, Goldring J, Lewis RA, Mandal S, Munavvar M, Rintoul RC, Shah PL, Singh S, Slade MG, Woolley A; BTS Interventional Bronchoscopy Guideline Group. Summary of the British Thoracic Society guidelines for advanced diagnostic and therapeutic flexible bronchoscopy in adults. Thorax. 2011 Nov; 66(11):1014-5. doi: 10.1136/thoraxjnl-2011-201052.
3. Katsanos K, Ahmad F, Dourado R, Sabharwal T, Adam A. Interventional radiology in the elderly. Clin Interv Aging. 2009; 4:1-15. Epub 2009 May 14. Review.

What is carotid artery stenting?

The carotid arteries are the two large arteries on each side of your neck that supply your brain, neck and face with oxygenated blood. Sometimes plaque builds up in the arteries, which results in a condition called carotid artery stenosis (also known as carotid artery disease). Stenosis means that the space inside the artery has narrowed, restricting blood flow.

Carotid artery stenting (CAS, also referred to as carotid artery angioplasty with stenting) is a minimally invasive treatment option for effectively managing carotid artery stenosis and preventing stroke. It is a non-surgical treatment in which catheters (thin hollow tubes) are used to place a stent (a metal mesh tube) in the affected artery to ensure the passage stays clear, thus restoring blood flow.

While some patients with carotid artery stenosis have no symptoms, the condition can lead to the formation of blood clots (thrombosis), mini-strokes (which are similar to strokes but only last a few minutes) and strokes (where the artery supplying blood to the brain is blocked). The CAS procedure is a possible alternative for patients for whom the traditional surgical option, carotid endarterectomy (CEA), may not be suitable.

How does the procedure work?

You will be given a local anaesthetic for the procedure. Using fluoroscopy to monitor and guide the process, the interventional radiologist will puncture an artery in your groin or arm with a needle, and will insert a balloon-tipped catheter into the carotid artery, guiding the catheter into the narrowed area. The balloon will then be inflated and deflated, compressing the fatty plaque or blockage against the artery walls, widening the blood vessel and increasing blood flow. After this, the balloon will be removed.

The interventional radiologist will use another catheter to place a stent, and, in some cases, will further expand the stent using another balloon-tipped catheter. The stent remains in place so that there is a clear passage in your artery.

Why perform it?

CAS may be an appropriate treatment for you if you have symptoms of carotid artery disease and are at increased risk of suffering complications from surgery. It may be beneficial if you have undergone traditional surgery but your arteries have become re-narrowed (called restenosis), if the location of the narrowing in the artery means it cannot be operated on or if narrowing has occurred following radiation treatment. It may also be considered as a treatment for you if you have no symptoms of carotid artery disease but are awaiting surgery for carotid stenosis.

What are the risks?

The most severe risks of CAS are stroke and death. Stroke can occur during the procedure and is usually caused by fragments dislodging from the plaque into the circulation of blood in the brain.

The minimally invasive treatment of CAS and the surgical treatment CEA have been shown to have similar short-term and long-term outcomes, though CAS is associated with a higher risk of stroke or death during the procedure if the patient is elderly. However, CAS has a lower risk of heart attack, cranial nerve palsy and bruising at the access site than CEA.

In some cases, patients experience a temporarily decreased heart rate or cardiac arrest when the carotid artery is widened at its main branch point, though these complications can be avoided when patients are given atropine.

Other possible complications of carotid artery stenting include spasm, the formation of blood clots, tearing in the artery wall and hyperperfusion syndrome, which can lead to problems with the nervous system.

You may also experience complications at the access site, including bleeding, bruising, blood clots, injury to the artery causing blood to leak and pool outside the arterial wall (called a pseudoaneurysm) and bleeding in the muscle and tissues behind the abdominal wall cavity. Many of these complications can be treated without surgery. You may have low blood pressure 2-24 hours after the procedure, but this does not cause any clinical problems.

Although it is uncommon, it is possible to have an allergic reaction to the dye used to enhance imaging.

Bibliography

1. Bonati LH, Lyrer P, Ederle J, Featherstone R, Brown MM. Percutaneous transluminal balloon angioplasty and stenting for carotid artery stenosis. Cochrane Database Syst Rev. 2012 Sep 12.
2. Brott TG et al, Stenting versus Endarterectomy for Treatment of Carotid-Artery Stenosis. N Engl J Med 2010; 363:11-23.

What is provocative discography?

Provocative discography is an image-guided procedure in which a radiological contrast agent is injected into the intervertebral disc (which is between two vertebrae). The contrast agent makes the area visible under imaging and so provides both anatomical and functional information about the disc.

How does the procedure work?

If the procedure is performed between two vertebrae, the interventional radiologist will insert a thin needle into the intervertebral disc under image guidance. If the procedure is performed on a disc in your neck, the entry point will be at the front or side of your neck, whereas if the disc being treated is lower down, the entry point will be in your back.

Once the interventional radiologist has completed the contrast injection, they will assess the shape of the disc on radiographs or a CT scanner. The contrast injection also increases the pressure between the discs, meaning that the functional evaluation in the discography procedure consists of pain induced by the interventional radiologist and the assessment of your response.

Why perform it?

You may be suitable for a provocative discography if you are suffering from persistent neck or back pain which has not responded to conservative treatment and if non-invasive tests such as MRI have not provided sufficient information about your condition.

You should only undergo a discography if you are being considered for surgery, as the anatomical and functional results of the procedure influence the surgical decision-making process.

What are the risks?

The reported rate of complications following the procedure is less than 1%. The most serious complication is infection. When puncturing an intervertebral disc, needle contact with a nerve may occur but this generally causes only temporary symptoms.

Bibliography

1. Kelekis AD, Filippiadis DK, Martin JB, Brountzos E. Standards of practice: quality assurance guidelines for percutaneous treatments of intervertebral discs. Cardiovasc Intervent Radiol. 2010 Oct; 33(5):909-13.
2. Filippiadis DK, Mazioti A, Papakonstantinou O, Brountzos E, Gouliamos A, Kelekis N, Kelekis A. Quantitative discomanometry: correlation of intradiscal pressure values to pain reduction in patients with intervertebral disc herniation treated with percutaneous, minimally invasive, image-guided techniques. Cardiovasc Intervent Radiol. 2012 Oct; 35(5):1145-53.

What is image-guided percutaneous drainage?

Image-guided percutaneous drainage involves using a catheter (a thin tube) to drain an abscess or a collection of fluid or air under image guidance. The interventional radiologist will insert a flexible catheter through a small cut in your skin and will guide the catheter to the collection of fluid or air. The fluid or air will then be collected in a drainage bag.

Drainage catheters are available in a variety of sizes, shapes and types. The interventional radiologist will choose the catheter according to the type of fluid, along with other factors.

How does the procedure work?

If you are on any medication that prevents blood clotting, you will stop taking it before the procedure, if possible.

You should not eat anything for at least four hours before the procedure starts. You may be asked to fast for longer, depending on the puncture and difficulty of your particular case. Before the procedure, the interventional radiologist will usually place a needle in your vein to make access easier during the procedure.

Why perform it?

Percutaneous drainage is recommended to treat fluid or air collections which produce symptoms (such as pneumothorax, which is the collection of air or gas in the gap between the chest wall and the lungs). It can also treat recurrent fluid collections by using medication and is a minimally invasive method of draining abscesses.

This procedure may not be suitable for you if you suffer from a blood clotting disorder or if the interventional radiologist cannot find a safe access route for the catheter.

The percutaneous drainage procedure cures infected fluid/air collections in over 80% of patients, though failure occurs in 5-10% of patients.

Because of the wide range of types of uninfected collections, the success rate of drainage for uninfected collections is highly variable.

What are the risks?

There are some risks associated with the procedure. Major complications include bacteraemia (the presence of bacteria in the blood, which occurs in 2-5% of cases) and septic shock (caused by severe infection and sepsis, which occurs in 1-2% of cases). Other complications include the risk of haemorrhage and superinfection (infection of a sterile collection of fluid, following a previous infection).

Bibliography

1. Bakal CW, Sacks D, Burke DR, Cardella JF, Chopra PS, Dawson SL, Drooz AT, Freeman N, Meranze SG, Van Moore A Jr, Palestrant AM, Roberts AC, Spies JB, Stein EJ, Towbin R; Society of Cardiovascular and Interventional Radiology Standards of Practice Committee. Quality improvement guidelines for adult percutaneous abscess and fluid drainage. J Vasc Intervent Radiol 1995; 6:68-90.
2. Silverman SG, Mueller PR, Saini S, et al. Thoracic empyema: management with image-guided catheter drainage. Radiology 1988; 169:5-9.
3. Van Sonnenberg E, D’Agostino HB, Casola G, et al. Lung abscess: CT-guided drainage. Radiology 1991; 178:347-351.

What is uterine fibroid embolisation?

Uterine fibroids cause a number of unpleasant symptoms, including pelvic pain and bleeding. Uterine fibroid embolisation is a minimally invasive procedure which aims to relieve the symptoms by preventing blood flow to the fibroids.

How should I prepare for UFE?

How does the procedure work?

The aim of the procedure is to stop blood flowing into the vessels which supply the fibroids whilst preserving blood flow to the surrounding area.

Why perform it?

Uterine fibroid embolisation is performed to reduce the symptoms caused by fibroids whilst avoiding surgical methods. Patient selection should always be performed by a gynaecologist, so if you are interested in seeing if you would be suitable for this procedure, you are advised to discuss this with your gynaecologist.

What are the risks?

Minor risks include bruising in the groin. More significant risks include the possibility that the glue or coils may move to other areas of the body and block other artery branches.

What is percutaneous tumour ablation?

Percutaneous tumour ablation refers to a range of techniques which destroy tumour tissue via needles placed through the skin. Some techniques use chemical agents (such as absolute ethanol), while others use physical agents, which may be thermal (using heat) or non-thermal. Thermal ablation techniques destroy tumours by using different kinds of applicators to freeze the tumour (called cryoablation) or to heat the tumour, such as radiofrequency ablation, laser ablation, microwave ablation and high-intensity focused ultrasound (HIFU).

Non-thermal ablation techniques use other sources of energy to achieve tumour destruction. Coblation uses an electrical plasma field to disintegrate the tissue by rupturing the bonds between the molecules which make up the tumour tissue. Irreversible electroporation uses high voltage electric shocks to pierce the cell membranes and cause cell death.

How does the procedure work?

The procedure will be carried out using image guidance, such as ultrasound, CT or MRI, to control the insertion of the devices and the energy deposition. You will be anaesthetised for the procedure. For most ablation procedures, the interventional radiologist will insert one or more needles or applicators into your tumour to deliver the chemical agent or physical energy.

Why perform it?

The goal of tumour ablation is to destroy the tumour without using surgery. Whether you are suitable for this procedure depends on the size and location of the tumour as well as your clinical situation.

What are the risks?

The insertion of the needle or applicator may cause bleeding or puncture surrounding organs. Another risk is the accidental leakage of the chemical agent or uncontrolled depositing of radiation energy, which may cause serious damage to the surrounding tissues.

Bibliography

1. Crocetti L, de Baere T, Lencioni R. Quality improvement guidelines for radiofrequency ablation of liver tumours. Cardiovasc Intervent Radiol. 2010 Feb; 33(1):11-7.

What is the endovascular treatment of abdominal aortic aneurysms (EVAR)?

The aorta is the largest vessel in your body and carries the blood from your heart to the rest of your organs. An aneurysm occurs if the arterial wall weakens and develops a bulge, meaning blood is flowing to the weakened area. Abdominal aortic aneurysms (AAA) are also known as ‘the silent killer’ because once they grow and rupture, there is an 80-90% risk of immediate death.

EVAR is a minimally invasive procedure in which an interventional radiologist places a covered stent (a metal mesh tube covered with fabric) into the area with the aneurysm so that blood can flow through the vessel. The stent is inserted through an artery in the patient’s groin, using X-rays to guide the stent to the aneurysm.

Why perform it?

If you have a small AAA that has a diameter of less than 5 cm, it is unlikely to rupture, so it is recommended that the aneurysm is regularly monitored by a vascular expert. If, however, you have an aneurysm that is smaller than 5 cm but it is growing by more than 1 cm every year or it is causing symptoms such as back pain and tenderness, EVAR may be beneficial for you.

If your aneurysm is larger than 5 cm, you will need treatment to prevent the aneurysm from rupturing. EVAR is a possible treatment option.

How does it work?

You will be given a combination of an epidural and a local anaesthetic for the procedure. The interventional radiologist will make a small cut at the top of each leg so that they can insert a short tube (known as a sheath), which allows the vessels in your groin to be accessed safely. Using fluoroscopy for guidance, the interventional radiologist will insert guidewires and catheters (thin flexible tubes). A contrast medium (dye) will be injected into the area being treated so the exact location of the aneurysm can be seen under imaging. The interventional radiologist will then use the guidewire to move a stent to the aneurysm.

When the stent is placed in the correct location, it will expand, sealing the aneurysm and restoring normal blood flow through the vessel.

After the procedure, your vital signs will be monitored and you will stay in hospital for 2-3 days. You may experience bruising and pain, though this can be treated with standard painkillers. Moving around once you are able to do so is encouraged. You will need to have the stent regularly checked using CT or ultrasound to ensure that it is in good condition and to avoid long-term problems.

What are the risks?

EVAR is recommended as a preventative treatment to avoid aneurysm rupture and death. The majority of patients suffer no immediate major problems and rupture of the aneurysm is avoided in over 99% of patients. There are lower rates of pain and serious complications than with surgery, but the main limitations of EVAR are that the stent may move to another area of the body and that blood may start collecting in the aneurysm again. This means that you will require regular monitoring, so that if any problems do occur they can be resolved as soon as possible.

Minor complications include the risk of bruising and infection. There are some serious complications associated with the procedure, including death, stroke, tissue death, limb loss and injury to the kidneys. The rate of serious complications is estimated to be less than 15%, and the risk of death during the procedure is less than 1.5%, which is nearly three times lower than the risk of dying during open surgery (around 4.5%). Some patients react to the iodine in the dye used for imaging, which can affect the kidneys.

Bibliography

1. Systematic review and meta-analysis of the early and late outcomes of open and endovascular repair of abdominal aortic aneurysm. Stather PW, Sidloff D, Dattani N, Choke E, Bown MJ, Sayers RD. Br J Surg. 2013 Jun; 100(7):863-72. doi: 10.1002/bjs.9101.
2. Endovascular stents for abdominal aortic aneurysms: a systematic review and economic model. Chambers D, Epstein D, Walker S, Fayter D, Paton F, Wright K, Michaels J, Thomas S, Sculpher M, Woolacott N. Health Technol Assess. 2009 Oct; 13(48):1-189, 215-318, iii. doi: 10.3310/hta13480. Review.
3. Quality improvement guidelines for imaging detection and treatment of endoleaks following endovascular aneurysm repair (EVAR). Rand T, Uberoi R, Cil B, Munneke G, Tsetis D. Cardiovasc Intervent Radiol. 2013 Feb; 36(1):35-45. doi: 10.1007/s00270-012-0439-4.

What is an aortic dissection?

The aorta is the largest artery in your body. An aortic dissection is when the layers of the aortic wall are separated by a tear in the inner wall. The aortic wall splits into two lumens (channels): a true lumen, meaning the original lumen; and a false lumen, which is in the aortic wall. If there is high blood pressure in the false lumen, the true lumen is compressed. This decreases blood supply to the organs, leading to organ failure and restricted blood supply to the lower limbs.

You may also experience a rapid widening of the part of the aorta near your heart, which can lead to it rupturing.

How does the procedure work?

The placement of a stent graft is usually performed under general anaesthesia. The interventional radiologist will use surgery to access an artery at the top of your leg for the procedure. They will also insert an angiography catheter through an artery in your right arm for injections of contrast material before and after the placing of the stent graft. The interventional radiologist will place a guidewire into your aortic arch and will then pass the stent graft over the wire and use this to cover the tear on the inner wall of the aorta. This protects the true lumen from the expansion of the false lumen.

If your case is critical, you may need to undergo additional stenting of these vessels to avoid restricting the blood supply.

If a stent graft is not enough to decompress the false lumen, you may be advised to have a procedure called fenestration of the intimal flap. This means that a hole will be made in the membrane between the true and false lumens to equalise the pressure between them. The interventional radiologist will create a connection between the lumens using a needle and positioning a wire through the puncture site. They will then widen the hole using a tiny balloon and may implant a stent to keep the connection open.

Why perform it?

The purpose of these procedures is to restore the true lumen as well as the blood supply to your organs and lower limbs. The procedures also stabilise the pressure and blood flow in the area and protect the aorta from widening.

What are the risks?

Depending on the location of the aortic tear, it may be necessary for the interventional radiologist to place the stent graft over the origin of an artery in your chest, which would result in a decreased blood supply to your left arm. This may lead to weakness of the arm, dizziness and ischaemic injuries to your brain. If you experience these symptoms, the artery will be treated to improve blood flow.

In some cases, it is not possible to separate the false lumen, which would make it necessary for you to undergo further treatment. Other risks include the misplacement of the stent graft and the rupture of the vein used for access, but these are rare.

Bibliography

1. Fanelli F, Dake MD. Standard of practice for the endovascular treatment of thoracic aortic aneurysms and type B dissections. Cardiovasc Intervent Radiol 2009; 32:849-860.

What is the endovascular treatment of arteriovenous malformations?

Arteriovenous malformation (AVM) refers to an abnormal connection between arteries and veins. Different types of AVMs occur in different clinical situations, including infantile haemangioma (a benign tumour made up of blood cells), and connections present at birth which are between vessels larger than capillaries (such as veins or arteries) – these are known as high-flow AVM.

The most common form of AVM is low-flow AVM, in which the abnormal connections are in an area with a low blood flow, meaning the space fills and empties slowly. This may be due to compression or gravity, a condition such as Klippel-Trénaunay syndrome or may be a combination of both these types. Another form of AVM is lymphatic malformations, though these are uncommon and may include cystic lesions (cysts, abscesses or bruising).

Klippel-Trénaunay Syndrome (KTS) is a rare congenital medical condition in which blood vessels and/or lymph vessels fail to form properly. The three main features are a port-wine stain, venous and lymphatic malformations, and soft-tissue enlargement of the affected limb. The condition tends to affect a single limb, usually a leg.

Although AVMs are congenital (present at birth), they are mostly diagnosed in adults under 40, and have a death rate of 10-15%.

In most cases, AVMs have no symptoms and so are discovered by chance, but the symptoms the patient experiences or does not experience depend on the location of the AVM. AVMs sometimes cause intense pain or bleeding and may lead to other serious medical problems. AVMs do not always require treatment.

You may be advised to undergo treatment for the AVM if you experience haemorrhaging, pain, ulceration, if your heart is pumping too much blood, if you have a mass which interferes with normal activity or growth, or if you develop disfiguring lesions.

The only indication that the treatment may not be suitable for you is if your anatomical situation would prevent it, meaning that the structure of the affected blood vessels may prevent treatment from being carried out. It is therefore vital that the interventional radiologist carries out imaging before the procedure to evaluate which type of AVM you have and how the feeding vessels are structured.

How does the procedure work?

The interventional radiologist will choose the type of endovascular procedure which is most suitable for you, depending on the site and type of your AVM. If the treatment is for infantile haemangioma, it may be removed surgically, to prevent psychological trauma, or it may be managed using embolisation.

If you are being treated for high-flow AVM, the therapy will aim to block the connection between the arteries and veins by embolising the tangle of blood vessels (nidus) or the central part of the lesion where the majority of the veins are present. The interventional radiologist will choose the material for the embolisation procedure based on the type of AVM you have and will aim to completely get rid of the nidus whilst also preserving normal blood flow. The materials used for the procedure are usually materials designed especially for the procedure, such as glue or metallic coils. Sometimes the nidus is directly punctured by injecting an embolic agent.

If you are undergoing treatment for low-flow AVM, you will be given an injection of sclerosing agent, a drug which is injected into vessels to make them shrink. In some cases, this will be done under fluoroscopy. There are limited treatment options for congenital venous dysplasia, but sometimes no treatment is needed. In severe cases, the interventional radiologist may use surgical stripping, sclerotherapy or an endovascular ablation technique. If you have symptoms on your skin, such as a port-wine stain, you may be advised to have laser treatment.

If you have a lymphatic malformation which contains fluid, a drainage treatment will be most suitable for you.

Why perform it?

Minimally invasive treatment can be performed for therapeutic reasons (to treat the condition) or for palliative reasons (to relieve the symptoms). The aim of the procedure is to exclude blood flow from the lesion and so reduce the symptoms and risks of AVM, such as bleeding.

The rate of bleeding varies from patient to patient, but if your AVM is associated with an aneurysm then the risk of bleeding is over 50%.

What are the risks?

Endovascular procedures to treat AVM also carry some risks, such as bleeding, bruising or ulcers at the site of the puncture, the embolic agent causing embolisation somewhere other than the target area, restricted blood supply if vessels supplying an area with blood are blocked, and toxicity, either locally or to other organs, caused by the blockage or sclerosing agent.

Bibliography

1. Sheehan J. Arteriovenous malformation. J Neurosurg 2013; Nov 1.
2. Sheehan JP, Starke RM. Aneurysm formation associated with ionizing radiation. World Neurosurg 2013; Nov 8.

What is an aneurysm?

An aneurysm is a localised bulge in an artery caused by weakening, which may be a result of atherosclerosis or an infection, or injury of the arterial wall. A peripheral aneurysm is an aneurysm which is not located in the aorta. They usually occur in the popliteal artery in your leg, though may also occur in other areas.

How does the procedure work?

The interventional radiologist will access the affected area by inserting the devices for the procedure into an artery in your groin, and will use image guidance to move the devices to the aneurysm. However, you may need surgery to reach the required artery. There are a number of options for treatment – the treatment you will undergo depends on the location and the shape of the aneurysm.

One possible option for endovascular treatment of peripheral aneurysms is to use a stent graft in the artery to cover the area affected by the aneurysm. Alternatively, the inside space of the aneurysm can be filled with embolic material (such as tiny coils or glue) which prevents blood flow to the aneurysm. The other possible option is to block blood flow to the vessel.

Why perform it?

It is important to treat aneurysms, as they may rupture and cause severe bleeding. Clots can form in the inside space of the aneurysm and then move, blocking or restricting blood flow. Aneurysms can also compress nerves and veins, leading to pain, numbness and weakness.

What are the risks?

There is a risk of complications at the entry point for the procedure, including bleeding, another aneurysm and the possibility of injuring a nerve. Materials used in the procedure may dislodge and block other arteries.

Bibliography

1. Uberoi R, Tsetis D, Shrivastava V, Morgan R, Belli AM. Standard of practice for the interventional management of isolated iliac artery aneurysms. Cardiovasc Intervent Radiol 2011; 34:3-13.

What is an endovascular treatment of stroke?

Endovascular treatment of stroke is the non-surgical treatment for the sudden loss of brain function due to blood clots. The treatment uses microcatheters (thin tubes visible under X-rays) which are inserted into the blood clot from the groin or the arm. The blood clot is removed from the blood vessel – this procedure is called a thrombectomy. If the blood clot cannot be removed, it is liquefied using drugs delivered through the catheter, in a procedure known as thrombolysis.

How does the procedure work?

The interventional radiologist will insert a catheter into an artery in your arm or groin and move it towards the blood clot under X-ray guidance. The blood clot is removed in a procedure called a thrombectomy. The blood clot may be removed by trapping it in a stent which is then pulled out with the clot, or the interventional radiologist may suck the clot out through the catheter.

If the clot cannot be removed, a medication may be applied through the catheter to liquefy it. If the blood vessel is too narrow, a balloon catheter can be used to restore its original size, in a procedure called an angioplasty. Afterwards, a stent is inserted to hold the blood vessel open.

Why perform it?

If you have suffered stroke caused by a blockage in a large artery but you are not suitable for or have not responded to thrombolysis, this procedure is a possible treatment for you.

What are the risks?

The insertion of catheters and guidewires in arteries to the brain carries a low but definite risk of bleeding or the movement of blood clots to previously unaffected parts of the brain. Endovascular treatment is inadvisable if your admission to hospital after the stroke was delayed, as this carries a higher risk of complications.

Bibliography

1. Sacks D, Black CM, Cognard C, Connors JJ 3rd, Frei D, Gupta R, Jovin TG, Kluck B, Meyers PM, Murphy KJ, Ramee S, Rüfenacht DA, Bernadette Stallmeyer MJ, Vorwerk D. Multisociety consensus quality improvement guidelines for intraarterial catheter-directed treatment of acute ischemic stroke, from the American Society of Neuroradiology, Canadian Interventional Radiology Association, Cardiovascular and Interventional Radiological Society of Europe, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, European Society of Minimally Invasive Neurological Therapy, and Society of Vascular and Interventional Neurology. J Vasc Interv Radiol. 2013 Feb; 24(2):151-63.

What is the endovascular treatment of visceral aneurysms?

An endovascular treatment is a treatment that is carried out inside the blood vessels, using small plastic tubes that are passed through a 2-3 mm hole in the skin and blood vessel wall.

An aneurysm is an abnormal enlargement of a blood vessel. Blood vessels have a tubular structure and most of these aneurysms are blister-like enlargements. Their walls may weaken and thus have a risk of tearing or bursting.

Visceral is a collective term for an organ in your body, such as the liver or spleen, so a visceral aneurysm is an aneurysm that occurs in an organ.

These abnormal enlargements have a risk of bursting and bleeding. The typical size that indicates a need for treatment is 2 cm. Endovascular treatment aims to stop blood flow to the aneurysm while maintaining blood flow to the organ.

How does the procedure work?

If you stop blood flowing, it will clot, just like a cut to the skin. The endovascular approach aims to stop blood flowing into the aneurysm whilst also preserving flow to the organ supplied by the affected blood vessel.

The interventional radiologist will usually enter a blood vessel in your groin and guide a 2-3 mm tube to the affected blood vessel. Typically a small coil (like the spring in a pen) will be pushed into the aneurysm or else into the blood vessel supplying the aneurysm.

Alternatively a small flexible metal tube (called a covered stent) is placed over the hole that feeds the aneurysm. These techniques will cause a clot to form in the aneurysm to stop the risk of rupture.

Why perform it?

A visceral aneurysm should be treated based on the risk of the wall of the aneurysm rupturing or breaking, which can cause serious bleeding. However, not all visceral aneurysms need treatment. The decision as to whether to manage the aneurysm conservatively and observe it or to treat it is also based on patient factors, appearance under imaging (typically ultrasound, CT and MRI) and any recent changes in the aneurysm.

It is generally agreed that larger aneurysms (over 2 cm) should to be considered for treatment.

What are the risks?

There are some minor risks, including the risk of a bruise in the groin. More significant risks include coils moving to another part of the body and blocking other artery branches. When treating an aneurysm, the blood flow in the main artery supplying the organ may decrease, causing an injury to the organ involved.

Bibliography

1. Belli A-M, Markose G, et al. The role of interventional radiology in the management of abdominal visceral artery aneurysms. Cardiovasc Intervent Radiol 2012; 35(2): 234-243.
2. Rossi M, Rebonato A, et al. Endovascular exclusion of visceral artery aneurysms with stent-grafts: technique and long-term follow-up. Cardiovasc Intervent Radiol 2008; 31(1): 36-42.
3. Spiliopoulos S, Sabharwal T, et al. Endovascular treatment of visceral aneurysms and pseudoaneurysms: long-term outcomes from a multicenter European study. Cardiovasc Intervent Radiol 2012; 35(6): 1315-1325.

What is fallopian tube recanalisation?

Fallopian tube recanalisation is the reopening of the fallopian tubes with the help of microcatheters (very fine, flexible plastic tubes that are visible under X-ray) and microguidewires (thin and flexible wires over which a microcatheter can be inserted into the body), which the interventional radiologist places into the vagina and cervix.

The microcatheter is inserted through the fallopian tube over a microguidewire. This clears any blockages in the fallopian tubes and restores the connection between the uterus and the abdominal cavity. This procedure is used to treat infertility caused by a blockage in the fallopian tubes.

How does the procedure work?

The first part of the procedure is similar to a standard gynaecological exam. The interventional radiologist will insert a speculum into your vagina and will spray a local anaesthetic on your cervix. They will then pass the catheter through your cervix and into your uterus. You may feel some discomfort at this point. The interventional radiologist will inject a few millilitres of a solution that is visible under X-ray through the catheter to make it easier to see the uterus and fallopian tubes during the procedure.

The interventional radiologist will then insert a microguidewire and microcatheter into one of your fallopian tubes and will push or flush the material causing the blockage (often a mucus plug) into your abdominal cavity. The closer to the uterus the blockage is, the more likely it is that the procedure will have the desired outcome. The interventional radiologist will then perform the same technique on your other fallopian tube.

Why perform it?

This procedure can ease infertility that is caused by blockage of the fallopian tubes.

What are the risks?

Tubal perforation (small holes in the fallopian tubes) occurs in about 2% of patients, but this has no severe complications. Pelvic infection is believed to occur in less than 1% of patients. In 3% of patients who get pregnant after the procedure, the embryo is found to be outside the uterus, known as an ectopic pregnancy. It is therefore recommended that you consult your gynaecologist as soon as you know that you are pregnant.

What is image-guided foreign body retrieval?

Foreign body retrieval is the removal, retrieval or manipulation of an item that has been introduced from the outside using image guidance. Foreign bodies are objects that originate outside the body and are usually the result of other medical procedures, such as endovascular (meaning in the arteries or veins) devices which have broken into smaller pieces, have become displaced or were mistakenly placed in the wrong area. Foreign bodies can also occur in extravascular locations, such as the biliary or urinary system and soft tissues.

How does the procedure work?

If you are on any medication that prevents blood clotting, you will stop taking it before the procedure, if possible.

You should not eat anything for at least four hours before the procedure starts. During the procedure, a needle will be placed in one of your veins to make access easier during the procedure, and the medical staff will monitor you throughout the procedure.

The technique used in the procedure depends on whether the procedure aims to remove or reposition the foreign body, as well as on the type and location of the item.

There are a number of systems and grasping devices which may be used for the procedure. The most common tool for endovascular removal is a snare device which consists of a snare wire loop, a snare catheter, a device used to insert a catheter and a device which helps move wires around during difficult procedures. The device is positioned in a blood vessel to capture the foreign body, which is then retrieved inside the introducer and out of the body.

Percutaneous foreign body retrieval is usually performed as an in-patient procedure, so you will stay in hospital overnight. The site of the puncture and your vital signs will be monitored for the first 4-6 hours following the procedure.

Why perform it?

There are a number of reasons why you may be advised to undergo percutaneous foreign body retrieval.

There are a number of risks associated with foreign bodies, including septic complications due to bacteria on the foreign body, as well as the risk of dislocated stents and coils which may cause blood clots and restrict blood flow in the vein. Inferior vena cava filters and fragmented guidewires may pierce the wall of the vein, and cement fragments on soft tissues can be painful.

Possible vascular foreign bodies (in your veins) include a fragmented or badly positioned central venous catheter or an inferior vena cava filter, an arterial catheter or guidewire, or a displaced arterial stent or embolic materials (such as a coil or plug).

Possible non-vascular foreign bodies include displaced ureteral and biliary stents and catheters as well as cement fragments on the soft tissue.

The procedure may not be suitable for you if you have a blood-clotting disorder.

The rate of successful foreign body retrieval is very high – over 90-95% of endovascular retrieval attempts are successful. If the foreign body cannot be retrieved using a minimally invasive technique or your doctor thinks that an endovascular retrieval of the foreign body would be too difficult or too risky, your doctor may suggest the possibility of using the traditional surgical approach.

What are the risks?

The risks associated with the procedure are fairly rare and usually do not require treatment. The most common complications are bruising at the groin, heart arrhythmia and flail tricuspid valve (a valve in the heart which has lost its normal support and flutters in the blood stream).

Bibliography

1. Sheth R, Someshwar V, Warawdekar G. Percutaneous retrieval of misplaced intravascular foreign objects with the Dormia basket: an effective solution. Cardiovasc Intervent Radiol 2007; 30:48-53.
2. Lawrence PF. Retrieval of iatrogenic intravascular foreign bodies. J Vasc Surg 2013; 57:276-81.
3. Mitchell WB, Bonn J. Percutaneous retrieval of a Greenfield filter after migration to the left pulmonary artery. J Vasc Interv Radiol 2005; 16(7):1013-7.
4. Fisher RG, Ferreyro R. Evaluation of current techniques for nonsurgical removal of intravascular iatrogenic foreign bodies. AJR Am J Roentgenol 1978; 130(3):541-8.

What is stenting?

Stenting is the placement of a stent inside your body. A stent is a mesh tube made out of metal which can be inserted into a passage in the body (such as a vein) to act as a skeleton and keep it open. You may be advised to have a stent placed if you have a blockage in your gullet or bowel which is caused by a tumour.

Symptoms of a blockage in the gullet, stomach or small intestine include being unable to consume an adequate amount of food, nausea and vomiting. If you have a blockage in your large intestine you may find it difficult to go to the toilet.

A stent may also be used to keep a fistula open, which is a connection between the gastrointestinal tract and the organs or tissues around it.

How does the procedure work?

Before the procedure, the interventional radiologist will outline the obstruction with contrast material under X-ray. You will have a local anaesthetic in your throat and be under mild sedation for the procedure. The interventional radiologist will introduce a device containing a wire and a catheter through your mouth and to the blockage in your gullet or small intestine. After the narrowing has been reached with the wire, a tiny balloon will be introduced and will slowly expand to dilate the area around the blockage.

Once the area has expanded enough, the interventional radiologist will implant the stent to bridge the blocked segment and keep it open. Sometimes a second dilation with a balloon is needed to help the stent expand better.

If the blockage is in your large intestine, the procedure will be performed through your anus, but otherwise the steps will be identical.

If you are being treated for a fistula, a stent covered with a membrane will be placed across the fistula before the procedure to protect it from the contents of the intestines.

Why perform it?

The aim of stenting for blockages in the gullet caused by a tumour is palliation, meaning the procedure is carried out to relieve any symptoms or pain caused by the blockage. Your symptoms should be relieved after the procedure and you will be able to eat normally again.

If you have an acute obstruction in your large intestine, meaning the blockage must be treated straight away, you may be advised to have this procedure as a bridge to surgery. This means you can choose to have the necessary operation later and avoid the risk of emergency surgery.

If you have a fistula, this procedure will protect it from the contents of your intestines and will allow the fistula to seal over time.

What are the risks?

One of the risks is stent migration, meaning it may move to another part of the body. It is also possible that the blockage will return, due to tumour overgrowth or if food or faeces develops into a solid lump in your rectum.

You may experience pain, bleeding or a delayed injury to the intestine, but these are rare.

Bibliography

1. Sabharwal T, Irani FG, Adam A. Quality assurance Guidelines for placement of gastroduodenal stents. Cardiovasc Intervent Radiol. 2007 Jan-Feb; 30(1):1-5.

What is a gastrojejunostomy?

A gastrojejunostomy is a minimally invasive procedure in which a long catheter-like tube (called a gastrojejunostomy tube) is inserted through your abdomen and into your small intestine. The tube provides nutritional support to patients who are unable to eat and are unsuitable for a gastrostomy tube due to a blockage preventing food from passing from the stomach into the small intestine, severe paralysis of part of the stomach or a high risk of choking.

How does the procedure work?

If you are on any medication which prevents blood clotting, you will stop taking it before the procedure, if possible.

You should not eat anything before the procedure. The interventional radiologist will insert a tube in your nose which will go into your stomach (called a nasogastric tube) and then will perform an ultrasound of your stomach to check the position of your liver and confirm that the tube is correctly placed.

The procedure is usually performed under local anaesthesia or moderate sedation. You may be given antibiotics to prevent infection, but this is not always necessary. You will lie on your stomach on a C-arm table, a table designed to be used in imaging procedures.

The procedure is similar to that of percutaneous gastrostomy. In most cases, you will be given an injection of glucagon hydrochloride, which temporarily paralyses the muscles in your stomach. The stomach puncture in gastrojejunostomy is aimed at the area where your stomach connects with your small intestine as this is where the tube will go.

The interventional radiologist will then insert a catheter along with a guidewire into the jejunum, which is the middle section of your small intestine. The guidewire will then be exchanged for a stiffer guidewire. The interventional radiologist will insert some dilators which will expand the area, creating enough space for the gastrojejunostomy tube, which is positioned over the stiff guidewire. The interventional radiologist will inject a few millilitres of contrast media through the gastrojejunostomy tube so that the position of the tube can be confirmed using fluoroscopy.

You will probably be required to stay in hospital overnight, although a gastrojejunostomy can also be performed as an out-patient procedure. You may experience slight discomfort at the entry point of the catheter for the first few hours following the procedure. The location of the tube will be checked daily for signs of leakage or infection. You will be allowed to eat between 8-24 hours after the gastrojejunostomy, after you have consumed 50 ml of water per hour for at least four hours without any negative effects. The T-fasteners used in the procedure can be safely removed 10-14 days after the procedure.

Why perform it?

The indications that a gastrojejunostomy may be beneficial for you are similar to those for a gastrostomy – you may be advised to have this procedure if you are unable to eat normally. The most common reasons for this are neurological causes (such as stroke or dementia), anatomical situations (such as during correction procedures of cleft lip and palate anomalies) and if a blockage is preventing food passing from your stomach to your small intestine.

Because gastrojejunostomy is associated with a reduced risk of aspiration pneumonia, your doctor may recommend it instead of a gastrostomy if you suffer from chronic acid reflux. If the interventional radiologist cannot access your stomach for the gastrostomy tube placement or you have previously had a gastrectomy (the surgical removal of all or part of your stomach), they may directly puncture your jejunum (the middle part of your small intestine) instead – this is known as a jejunostomy.

The reasons why this procedure may not be suitable for you are also similar to those for a gastrostomy. You should not undergo the procedure if you have a blood-clotting disorder, if your colon or liver is positioned between your stomach and abdominal wall (as this prevents a safe access route), if you have peritonitis (inflammation of the thin tissue wall which covers most of your abdominal organs as well as the inner abdominal wall), or if you suffer from untreatable massive ascites (abnormal fluid in your abdomen).

This procedure may not be suitable for you if you have dilated blood vessels in your gullet or stomach, changes in the top layer of the stomach lining, if you have abnormal cell growth in the wall of your stomach, cancer that affects the lining of the abdominal cavity, if you are morbidly obese or if you have had previously had surgery in the area.

The technical success rate ranges from 85-95%.

What are the risks?

The possible complications for a gastrojejunostomy are similar to those for a gastrostomy procedure: peritonitis (inflammation of the thin tissue wall within your abdomen), skin infection around the catheter entry site and bruising. As long as you are suitable for the procedure and the interventional radiologist chooses the technique most suited for you, the risk of complications is low (the rate of procedure-related mortality is 2.4%).

Bibliography

1. Given MF, Hanson JJ, Lee MJ. Interventional radiology techniques for provision of enteral feeding. Cardiovasc Intervent Radiol 2005; 28(6):692-703.
2. van Overhagen H, Schipper J. Percutaneous jejunostomy. Semin Intervent Radiol 2004; 21(3): 201-206.
3. Bell SD, Carmody EA, Yeung EY, et al: Percutaneous gastrostomy and gastrojejunostomy: additional experience in 519 procedures. Radiology 1995; 194:817-820.
4. Hallisy MJ, Pollard JC. Direct percutaneous jejunostomy. J Vasc Intervent Radiol 1994; 5:625-632.

What is a gastrostomy?

Gastrostomy is a procedure in which a gastrostomy tube is placed into your stomach for nutritional support.

You may be recommended for a gastrostomy if for some reason you are unable to eat enough to sustain you, such as if you are unable to swallow safely.

A gastrostomy tube is a tube which may resemble a catheter or a button (with a detachable extension). Both types of tube have a balloon on the tip which keeps them in the correct area and both are therefore suitable for long-term use.

How does the procedure work?

If you are on any anti-coagulation or anti-platelet medication (medication which prevents blood clotting), you will stop taking it before the procedure, if possible.

You should not eat anything before the procedure. The interventional radiologist will insert a tube in your nose which will go into your stomach (called a nasogastric tube) and then will perform an ultrasound of your stomach to check the position of your liver and confirm that the tube is correctly placed.

A gastrostomy is usually performed under local anaesthesia or moderate sedation. You may be given antibiotics beforehand to prevent infection, but this is not always necessary. You will lie on your stomach on a C-arm table, a table designed to be used in imaging procedures.

In most cases, you will be given an injection of glucagon hydrochloride, which temporarily paralyses the muscles in your stomach. Then, air will be entered through the nasogastric tube and into your stomach. The interventional radiologist will perform a fluoroscopy of the stomach to determine the exact puncture site, which is usually over the middle part of the stomach. In some cases, such as if part of your colon or liver is in front of your stomach, the gastric procedure may be carried out using CT.

The interventional radiologist will then perform a gastropexy, which is the fixation of the anterior gastric wall to abdominal wall, and here at least three anchors (T-fasteners) will be used to make a triangle on the abdominal wall. The interventional radiologist will use a small needle to puncture your stomach in the centre of the triangle.

The interventional radiologist will confirm the position of the needle tip within your stomach by injecting air or a contrast substance. They will then use the needle to position a guidewire inside your stomach.

The position of the needle tip within the stomach is confirmed using air or contrast media under imaging. The interventional radiologist will then position a guidewire through the needle and into your stomach, followed by a series of dilators which will be inserted over the guidewire to expand the area around it. The gastrostomy tube will then be inserted into your stomach. It has a balloon at the end which will be inflated to keep it in place and the guidewire will be safely removed. The interventional radiologist will inject a few millilitres of contrast media through the gastrostomy tube so that the position of the tube can be checked using fluoroscopy.

You will probably be asked to stay in hospital overnight, though the procedure can in some cases be performed as an out-patient procedure. You may experience some discomfort around the catheter in the first few hours following the procedure.

The entry point for the gastrostomy tube should be checked daily for signs of leakage or infection. You will be able to begin eating again 8-24 hours after the procedure and after you have consumed 50 ml of water per hour for at least four hours without any negative effects. The gastropexy anchors can be safely removed 10-14 days after the procedure.

Why perform it?

You may be advised to have a gastrostomy tube if you are unable to eat normally. The most common reasons for being unable to eat are neurological causes that prevent normal swallowing (such as stroke or dementia), anatomical situations (such as during correction procedures of cleft lip and palate anomalies) and obstruction of the gullet (such as presence of head and neck tumours, post-radiation conditions). If you have a cancerous tumour in your bowel which causes a blockage, you may be recommended for a gastrostomy tube to decompress the stomach.

As a general rule, enteral feeding (delivering food directly into the stomach) is recommended when the patient is unable to eat for at least 7-14 days. If you have been unable to eat normally for more than 30 days, you may be recommended to have a gastrostomy or a gastrojejunostomy tube placed. If you are unable to eat but are expected to be able to eat normally within 30 days, your doctor will suggest a nasogastric tube (a tube delivering food through your nose to your stomach) or nasoenteric tube (which delivers food through your nose to your small intestine).

The procedure is not recommended for you if you have a blood-clotting disorder, if your colon or liver is positioned between your stomach and abdominal wall (as this prevents a safe access route), if you have peritonitis (inflammation of the thin tissue wall which covers most of your abdominal organs as well as the inner abdominal wall), if you suffer from untreatable massive ascites (abnormal fluid in your abdomen), or if you have a blockage in your bowel (unless the gastrostomy is recommended to decompress your stomach).

This procedure may not be suitable for you if you have dilated blood vessels in your oesophagus or stomach, changes in the top layer of the stomach lining, abnormal cell growth in the wall of your stomach, cancer that affects the lining of the abdominal cavity, if you are morbidly obese or if you have had previous gastric or upper gastrointestinal surgery.

The technical success rate of the gastrostomy procedure is very high, at around 97%.

What are the risks?

The most common complications include skin infection around the gastrostomy entry point and bruising. It is possible that the colon could be perforated during the placement of the tube, which can lead to severe peritonitis. If the gastrostomy tube is placed through the left hepatic lobe of your liver, you may experience bruising in your liver.

As long as you are suitable for the procedure and the interventional radiologist chooses the technique most suited for you, the risk of complications is low (the rate of major complications is less than 3%).

Bibliography

1. de Baere T, Chapot R, Kuoch V, et al. Percutaneous gastrostomy with fluoroscopic guidance: a single-centre experience in 500 consecutive cancer patients. Radiology 1999; 210(3):1076-83.
2. Covarrubias DA, O’Connor OJ, McDermott S, Arellano RS. Radiologic percutaneous gastrostomy: review of potential complications and approach to managing the unexpected outcome. AJR Am J Roentgenol 2013; 200(4):921-31.
3. Laasch HU, Martin DF. Radiologic gastrostomy. Endoscopy 2007; 39(3):247-55.
4. Given MF, Hanson JJ, Lee MJ. Interventional radiology techniques for provision of enteral feeding. Cardiovasc Intervent Radiol 2005; 28(6):692-703.

What is HIFU?

High-intensity focused ultrasound (HIFU) is a non-invasive therapy that uses focused ultrasound waves to thermally ablate a portion of tissue, meaning the tissue is destroyed using intense heat. The intense heat causes tissue coagulation necrosis, cavitation and heat shock in the cells, meaning that the portion of tissue which is being ablated is destroyed.

How does the procedure work?

High power ultrasound can be focused on a targeted point to raise the temperature to 70-80°C.

HIFU uses sonication (sound energy) to create this heat. Each sonication heats only a small focal target, so the interventional radiologist will use multiple sonications to ablate the whole affected area. The interventional radiologist may use diagnostic sonography with focused ultrasound (USgFUS or USgHIFU) or magnetic resonance guidance with focused ultrasound (MRgFUS).

Why perform it?

You may be advised to have the procedure to treat uterine fibroids or to alleviate pain from bone cancer. HIFU can also be used to treat prostate cancer, both as a primary treatment and after radiotherapy.

Investigations into using HIFU to treat liver, breast and brain tumours have had promising results.

Positive results with transcranial MR-guided focused ultrasound surgery (tcMRgFUS) as a non-invasive treatment of essential tremors, neuropathic pain and Parkinson’s disease have been reported in literature. There have also been some investigations into the use of HIFU for temporarily opening the blood-brain barrier, allowing absorption of drugs into the brain.

A minimally invasive catheter-based system designed to ablate heart tissue responsible for atrial fibrillation has been approved for use in Europe and is undergoing an FDA approved trial in the United States.

What are the risks?

The risks of this procedure are related to non-target specific sonification (when tissue surrounding the area being treated is affected by the ultrasound waves). A further possible risk is the incomplete destruction of the lesion due to inadequate heating.

HIFU is not suitable for use in some areas of the body as ultrasound waves have a negative effect on some materials, though your interventional radiologist can avoid these effects by doing the procedure under magnetic resonance imaging.

Bibliography

1. Sanghvi NT. High-intensity focused ultrasound treatment of prostate cancer. J Acoust Soc Am. 2013 Nov; 134(5):4089.
2. Xiaoping L, Leizhen Z. Advances of high intensity focused ultrasound (HIFU) for pancreatic cancer. Int J Hyperthermia. 2013 Nov; 29(7):678-82.

What are the endovascular placement and retrieval of an IVC filter?

IVC filters are metal devices which are designed to be used in the inferior vena cava (IVC), the large vein that carries deoxygenated blood from the lower half of the body back to the heart.

A pulmonary embolus is a blockage in the main artery of a lung. IVC filters can be used to prevent or manage pulmonary emboli and deep vein thrombosis (DVT), and can be temporary or permanent. The shape of an IVC filter resembles that of an umbrella, and it functions in a similar way.

How does the procedure work?

The interventional radiologist will insert a 3 mm plastic tube (called a sheath) into the base of your skull or your groin. They will guide the sheath to the blood clot in the inferior cava vein, which is where the IVC filter will be placed.

If you receive a temporary IVC filter, the interventional radiologist will remove the filter after the necessary period of time has passed. To remove the IVC filter, the interventional radiologist will insert a long plastic tube and a goose-neck system (like a miniature lasso) as before and use this to remove the IVC filter.

Why perform it?

There are a number of treatments available to manage or prevent pulmonary emboli and DVT, including conservative (medical) therapy, IVC filters, intravenous systemic thrombolysis, catheter thrombolysis and a surgical operation.

Your suitability for this treatment depends on a number of factors, including how stable your blood pressure is and how well your heart is working. Other factors which will be taken into consideration are the type of IVC filter and your clinical situation, as permanent placement means you will need to take medication to prevent blood clotting for the rest of your life.

What are the risks?

There are some minor risks, including infection and bruising at the puncture site in your neck or groin. Major risks include the filter moving to another part of your body, the development of another thrombus, or a leg of the IVC filter breaking through the wall of the vein, which can be painful.

If you have a permanent IVC filter, the medication preventing blood clots that you will need to take carries further risks.

Bibliography

1. Eight-year follow-up of patients with permanent vena cava filters in the prevention of pulmonary embolism: the PREPIC (Prevention du Risque d’Embolie Pulmonaire par Interruption Cave) randomized study. Circulation 2005; 112:416-22.
2. Fox MA, Kahn SR. Postthrombotic syndrome in relation to vena cava filter placement: a systematic review. Journal of vascular and interventional radiology: JVIR 2008; 19:981-5.
3. Hann CL, Streiff MB. The role of vena caval filters in the management of venous thromboembolism. Blood reviews 2005; 19:179-202.

What is percutaneous image-guided jejunostomy?

If you have been unable to eat for over seven days, you may need to receive nutrients intravenously (called parenteral feeding) or via a tube into the stomach or small bowel (called enteral feeding). There are a number of ways that enteral feeding can be carried out, such as placing a tube through the nose and into the stomach. This is called a nasogastric or nasoenteric feeding tube, and is the preferred option if your anticipated need is less than 30 days.

However, nasoenteric tubes are not suitable for use longer than 30 days, as they can cause considerable discomfort and complications such as inflamed sinuses. If your need is anticipated to be for longer than 30 days, a better option for you is direct enteral access. This involves placing a tube directly into your stomach or bowel. This used to require surgery, but minimally invasive techniques are now available as an alternative, such as percutaneous image-guided jejunostomy.

During a percutaneous image-guided jejunostomy, an interventional radiologist will place a tube directly through the abdominal wall and into part of your small intestine called the jejunum, providing a way for nutrients to enter your body.

How does the procedure work?

The procedure is carried out using fluoroscopic guidance. The interventional radiologist will first inflate your stomach using a nasogastric tube. This will aid the fluoroscopy, the required puncture and enlargement of the tract. In rare cases, nasogastric access may not be possible, so the stomach is inflated using a needle introduced into the stomach, under image guidance.

To minimise the risk of puncturing the colon, the interventional radiologist may administer a contrast liquid into your colon the day before the jejunostomy procedure, to help visualise the colon.

During the jejunostomy procedure, the interventional radiologist will puncture the skin where the tube will be inserted, and then direct the needle under image guidance to the small intestine. The needle may be attached to an anchor, which the interventional radiologist will direct into the jejunum using a guidewire. To ensure there is enough space for the tube, the tract will be expanded using dilators or tiny balloons, which the interventional radiologist will insert using a separate guidewire.

The interventional radiologist will then insert a jejunostomy tube over the guidewire, using fluoroscopy to confirm its position. Once it has been confirmed that the tube is correctly placed, the interventional radiologist will remove the guidewires and secure the tube to the skin using anchors.

Why perform it?

There are a number of reasons why a jejunostomy tube may be beneficial for you. The tubes may be used in infants and children who have issues with swallowing due to surgery. They may also be used in patients who are unable to swallow as a result of central nervous system disorders, patients who require feeding supplementation or special diets or to administer frequent doses of multiple medications. Patients who are chronically ill or neurologically impaired may require a tube indefinitely.

Jejunostomy is an alternative for patients who may not be able to have a feeding tube in their stomach.

What are the risks?

It is very common for air or gas to be present in the abdominal cavity as well as bruising. However, these usually have no adverse clinical effect.

Minor complications that you may experience include incorrect tube placement or tube movement, granulation tissue formation (skin that is red and sore as it heals) and minor bleeding from the site. Some patients develop a condition called intussusception, when part of the intestine folds onto another section of the intestine, causing bowel obstruction. Another possible complication is local infection.

Other procedure-related complications include damage to the abdominal or gastric walls caused by decreased blood supply and leakage from the catheter. Major complications are rare, but include perforation of the small intestine and inflammation of the lungs or airways caused by inhaling food or other substances.

Bibliography

1. Olson DL, Krubsack AJ, Stewart ET “Percutaneous enteral alimentation: gastrostomy versus gastrojejunostomy,” Radiology 1993.
2. Friedman JN, Ahmed S, Connolly B, Chait P, Mahant S, “Complications associated with image-guided gastrostomy and gastrojejunostomy tubes in children,” Pediatrics. 2004 Aug; 114(2):458-61.

What is percutaneous nephrostomy?

A nephrostomy tube is a thin, flexible, plastic tube that is used to drain urine from the kidney. Urine leaving the kidney is collected in a plastic bag attached to the tube outside your body. The bag can be strapped to your waist or leg so you can move freely.

Percutaneous nephrostomy describes the procedure in which the nephrostomy tube is inserted through the skin and into the kidney.

How does the procedure work?

You will lie on your stomach, usually with one side slightly raised on a pillow. You will be given an injection of a painkiller and a sedative to reduce any discomfort. The area of skin around the entry site will be anaesthetised before the procedure.

Under the guidance of ultrasound, X-ray or CT, the interventional radiologist will insert a needle through the skin and into the kidney and will then put a wire through the needle and insert the nephrostomy tube into the kidney over the wire.

Why perform it?

You may be advised to have this procedure if the passage of urine to your bladder is blocked, most commonly because of a stone, infection, injury to the ureter or cancer. It can also be the first step of a procedure known as percutaneous/ante grade ureteric stenting.

What are the risks?

Some patients report minor bleeding from the kidney after a nephrostomy. Severe bleeding that requires treatment occurs in less than 5% of patients. In less than 1/500 patients an adjacent organ is injured during the nephrostomy. Although temporary low-grade fever is common after the procedure, a high fever occurs in around 1-3% of patients, which is usually the result of an unresponsive infection.

Bibliography

1. Ramchandani P, Cardella JF, Grassi CJ, Roberts AC, Sacks D, Schwartzberg MS, Lewis CA; Society of Interventional Radiology Standards of Practice Committee. Quality Improvement Guidelines for Percutaneous Nephrostomy. J Vasc Interv Radiol. 2003 Sep; 14(9 Pt 2):S277-81.

What are neurolysis, nerve block and plexus block?

Neurolysis is the deliberate destruction of a nerve or a network of interlacing nerves (plexus) with the aim of providing permanent relief from pain by interrupting the transmission of pain signals in the nerves.

Nerve block refers to temporarily blocking the function of a nerve by injecting painkillers into the area around the affected nerve, thus blocking the transmission of pain signals. This temporarily disables the nerve without causing permanent damage.

How does the procedure work?

If you are undergoing neurolysis, there are a number of techniques which the interventional radiologist may use. The most common method of causing permanent nerve destruction is the injection of a chemical such as alcohol. Alternately, the interventional radiologist may choose to use ablation techniques to destroy the nerves. In these cases, the interventional radiologist will insert a needle or a thermal probe into the area so it is in contact with the nerve or the plexus.

If you are having a nerve block, the interventional radiologist will use a single thin needle to inject anaesthetics (sometimes mixed with anti-inflammatory drugs) into the area around the nerves responsible for pain.

Because these procedures are carried out under image guidance, the interventional radiologist can target the precise area, which reduces the risk of complications when targeting deeply situated nerves.

Why perform it?

Neurolysis can be used to treat severe diseases including chronic pain. It is most often used as a pain control technique for cancer patients but can also be used to treat other conditions causing chronic pain which appear to have no cure or no clear cause.

What are the risks?

There are some minor side effects associated with the procedure, depending on the nerve targeted. For example, neurolysis in the abdominal splanchnic nerves often causes orthostatic hypotension, also known as ‘head rush’, when a person’s blood pressure falls when standing or stretching. Severe complications for nerve block or neurolysis are rare. However, as is the case with all procedures near the spine, there is an exceptional risk of paralysis of the area supplied by the nerve or elsewhere.

Bibliography

1. Akural E, Ojala RO, Järvimäki V, Kariniemi J, Tervonen OA, Blanco Sequeiros R. MR-guided neurolytic celiac plexus ablation: an evaluation of effect and injection spread pattern in cancer patients with celiac tumor infiltration. Cardiovasc Intervent Radiol. 2013 Apr; 36(2):472-8.
2. Masala S, Crusco S, Meschini A, Taglieri A, Calabria E, Simonetti G. Piriformis syndrome: long-term follow-up in patients treated with percutaneous injection of anesthetic and corticosteroid under CT guidance. Cardiovasc Intervent Radiol. 2012 Apr; 35(2):375-82.
3. Yilmaz S, Ceken K, Alimoglu E, Sindel T. US-guided femoral and sciatic nerve blocks for analgesia during endovenous laser ablation. Cardiovasc Intervent Radiol. 2013 Feb; 36(1):150-7.

What is a percutaneous arthrodesis?

Percutaneous arthrodesis of the facet joints or sacroiliac joints is a treatment for the pain caused by facet joint syndrome or sacroiliac joint pain that has not responded to other treatments. The procedure relieves pain by fusing the affected joints together using screws or similar devices.

Facet joint syndrome is a form of chronic lower back pain. It is characterised by stiffness and pain that increases when twisting and bending backwards. It is frequently caused by osteoarthritis, a type of arthritis that causes joint cartilage to deteriorate. This can also be caused by the joints bearing an unusual amount of weight as well as by repetitive stress injury. Facet joint syndrome is not easy to diagnose because it may be unclear where the source of the pain is located, making it easy for symptoms to be confused with the many other causes of back pain.

In some cases, lower back pain can be the result of painful sacroiliac joint dysfunction, an inflammation of the sacroiliac joint, which is located at the bottom of the spine. Sacroiliac joint pain is complex and can be expressed in one of several forms, such as sciatica.

Percutaneous arthrodesis treatment is used to stabilise the movement of the spine in the facet joints. The procedure corrects unwanted spinal motion and unstable facet joints.

How does the procedure work?

You will have a local anaesthetic and be mildly sedated for the procedure.

The interventional radiologist will use X-ray guidance to insert facet screws to the affected area of your spine. The joints are temporarily held together with a wire while the screws are fixed in place. A tissue dilator system is introduced along the wire, and then the fusion implants (usually three for one side) are positioned using a pin. Then, under X-ray guidance, the interventional radiologist will drill and shape the area.

Why perform it?

Percutaneous arthrodesis can be used to treat degenerative disc disease, which is characterised by back pain as a result of wearing out the intervertebral discs in the lower back, degenerative disease of the facet joints with instability trauma (meaning a fracture or dislocation), displacement of a vertebra or the vertebral column, defects in the vertebra, or a non-healing fracture.

It can also be recommended to treat any previous fusions that have failed, causing discomfort, further instability or deformity.

You may be suitable for percutaneous facet fusion:  if you have sacroiliac joint pain (i.e. a positive result on two diagnostic tests and pain relief of at least 75% from a single diagnostic intra-articular injection), or if you have not responded to medical or physical therapy.

What are the risks?

Risks include the screws loosening, disassembling, bending, dislocating or breaking. This may happen straight after the procedure or may be delayed.

Some patients may experience a physiological reaction after surgery and show intolerance to having a foreign object inside their body. Risks also include changes to your spine, changes to your height, infections, bleeding and the growth of the fused bone around the treated area. You may also experience a fracture that does not heal properly, neurological disorders, pain, abnormal sensations and the forming of scar tissue.

What are percutaneous therapies for spinal stenosis?

Spinal stenosis refers to abnormal narrowing in the spinal canal, meaning that the space around the spinal cord narrows and presses on nerve tissue. When this occurs in the lower part of the back, it is referred to as lumbar spinal stenosis.

Because a standing position can narrow this area, you may feel better when you are not standing upright, such as when you sit down or cycle. Neurogenic intermittent claudication describes cramping or weakness in the legs caused by inflammation of a nerve and is due to degenerative lumbar spinal stenosis.

Percutaneous therapies (delivered through the skin) for spinal stenosis involve implanting tools designed to widen the affected area of the spine, called interspinous spacers, using fluoroscopic or CT guidance.

How does the procedure work?

The procedure is performed under local anaesthesia and mild sedation. The procedure is known as lumbar decompression surgery and it aims to widen (decompress) the spinal canal. You will be asked to lie on your stomach with your feet slightly raised.

The procedure is done under imaging. A trocar is inserted into the skin, allowing access to the area to be treated. More trocars of slightly wider sizes are inserted over each other. This allows for a wider opening through which the procedure can be carried out. The spacers will then be inserted, and should not be positioned too deeply or too superficially.

Why perform it?

You may be recommended for this treatment if you are suffering from degenerative lumbar stenosis and neurogenic intermittent claudication or progressive pain in your lower back which is made worse by standing upright and improved by sitting down, and if your symptoms have not improved after conservative treatments (medical and physical therapy).

Percutaneous treatments for spinal stenosis aim to widen the affected area in addition to acting as a shock absorber, which reduces the load on the facet joints. As the degeneration of disc joints is a common cause of back pain, redistributing the load on the joints should help ease the pain.

What are the risks?

The risks of this procedure include a delayed fracture to your spine and the possible dislocation of the implants.

What is Y-90 radioembolisation?

Y-90 radioembolisation is a palliative treatment for primary liver lesions and liver metastatic disease which uses ionising radiation to shrink tumours. It is generally used to relieve the symptoms of liver tumours rather than to cure the underlying condition.

The liver has two sources of blood supply: the hepatic artery and the portal vein. Liver tumours tend to rely on the hepatic artery for their blood supply.

During a radioembolisation procedure, an interventional radiologist injects microspheres filled with the radioactive isotope yttrium (known as Y-90) into the vessels feeding the tumour. Because the radiation is focused only on the tumour, higher and more effective radiation doses can be used compared to other treatments.

How does the procedure work?

Depending on your individual situation, you may be given the procedure as an out-patient or you may require hospital admission following the treatment. The interventional radiologist will carry out the procedure using fluoroscopic guidance.

You will be given a local anaesthetic. After this, the interventional radiologist will insert a catheter (a thin tube) and a guidewire into an artery. You will then have some images taken of your upper abdominal arteries to show the exact location of the vessels feeding the tumour. The interventional radiologist will then insert microspheres filled with Y-90 into these vessels to deliver a high dose of radiation to the cancer cells. This radiation dose will decrease over the following two weeks.

Your vital functions will be monitored during the procedure. You may be given antibiotics to prevent infection, and, if necessary, IV analgesics or medication to prevent nausea.

Why perform it?

If you have an inoperable liver tumour or if you are not fit for surgery, you may benefit from Y-90 radioembolisation. Y-90 is beneficial for hepatocellular carcinoma (the most common type of cancer) affecting the portal vein of the liver, or if you have not responded to chemoembolisation.

Because the radiation dose is delivered directly to the tumour, the dose is higher than in standard radiation therapy and there are fewer possible complications. Radioembolisation can extend the patient’s life expectancy from months to years, as well as improving quality of life. In some patients, this procedure enables them to undergo surgery or liver transplantation.

What are the risks?

Y-90 radioembolisation is a relatively safe procedure. The most common complication is post-radioembolisation syndrome, which occurs in around 50% of patients. Symptoms include fatigue, low-grade fever, nausea, vomiting and abdominal discomfort.

Less common complications include a build-up of fluid, high levels of alkaline phosphatase and infection. You may also experience stomach ulcers, inflammation of the pancreas, raised blood pressure, gallbladder inflammation or pneumonia. As with all percutaneous procedures, there is a risk of bleeding or damage to a blood vessel.

In some cases, patients react to the iodinated contrast materials used in the procedure, experiencing allergic reactions and harmful effects on the kidneys.

Bibliography

1. Mahnken AH, Spreafico C, Maleux G, Helmberger T, Jakobs TF. Standards of practice in transarterial radioembolization.  Cardiovasc Intervent Radiol. 2013 Jun; 36(3):613-22.
2. Kennedy A, Nag S, Salem R, Murthy R, McEwan AJ, Nutting C, Benson A 3rd, Espat J, Bilbao JI, Sharma RA, Thomas JP, Coldwell D. Recommendations for radioembolization of hepatic malignancies using yttrium-90 microsphere brachytherapy: a consensus panel report from the radioembolization brachytherapy oncology consortium.  Int J Radiat Oncol Biol Phys. 2007 May 1; 68(1):13-23.

What is renal denervation?

Resistant hypertension refers to high blood pressure which has not responded to medication. Renal denervation (RDN) is a minimally invasive procedure to treat resistant hypertension. The procedure uses radiofrequency ablation to burn the nerves in the renal arteries. This process causes a reduction in the nerve activity, which decreases blood pressure.

How does the procedure work?

You will have a local anaesthetic for the procedure and it will be carried out under image guidance.

The interventional radiologist will insert a catheter into the femoral artery in your thigh, and through this will access the arteries feeding your kidneys. During the RDN procedure, radiofrequency pulses are applied, burning the nerves in the walls of the renal arteries.

The aim of the procedure is to burn the renal nerves without damaging the arteries. Each application of radiofrequency ablation will last for around 1-2 minutes, though this depends on the device used. The interventional radiologist may use a catheter (tube) radiofrequency generator, which requires more than one application of the radiofrequency pulse during the session, or a radiofrequency balloon generator, which requires a single application of radiofrequency pulse.

Why perform it?

This procedure is designed for patients who suffer from resistant hypertension, i.e. those who have already unsuccessfully tried a regimen of at least three medications to treat hypertension at the same time.

In order to be suitable for this procedure, you will need to have strong and healthy veins.

What are the risks?

As RDN is a relatively new procedure, little is known about its long-term effects. However, it has been shown to be an effective treatment for resistant hypertension.

There are a number of risks associated with the procedure. Some patients experience bradycardia (slow heart rate) during the procedure. If this happens, you will be given atropine.

The radiofrequency ablation may cause changes to the wall of the arteries, which can sometimes lead to renal artery stenosis (the narrowing of the renal arteries).

The imaging used during the procedure also has a number of risks. Bruising can occur to the punctured site at the top of the thigh. Other possible complications include pseudoaneurysm (a bruise caused by a leaking hole in an artery) and tearing in the renal arteries.

Bibliography

1. Staico R, Armaganijan L, Moreira D, et al. Renal sympathetic denervation and ventricular arrhythmias: a case of electrical storm with multiplerenal arteries. EuroIntervention. 2013 Nov 8.
2. Moss J, Vorwerk D, Belli AM, Peregrin J, Lee M, Reekers J. Cardiovascular and Interventional Radiological Society of Europe (CIRSE) Position Statement on Renal Denervation for Resistant Hypertension. Cardiovasc Intervent Radiol. 2013 Nov 13.
3. Thukkani AK, Bhatt DL. Renal denervation therapy for hypertension. Circulation. 2013 Nov 12; 128(20):2251-4.

What is a salivary gland intervention?

The salivary glands produce saliva, which drains into the mouth via ducts and helps break down food. There are three major pairs of such glands – the submandibular glands (under the jawbone), the parotid glands (between the ear and the jaw) and the sublingual glands (beneath the tongue). Sometimes the glands are obstructed because stones have formed or the ducts are restricted for other reasons. These conditions affect about 1% of the adult population.

Surgical procedures for openingrestrictions of the salivary ducts or to extract stones can be complicated, and carry risks of facial nerve injury and paralysis. Interventional radiology offers minimally invasive procedures, such as sialoplasty, which uses dilators, baskets or balloons to restore proper function in the submandibular and parotid glands.

How does the procedure work?

The sialoplasty procedure is carried out using fluoroscopy for guidance. An interventional radiologist will insert a catheter (a thin flexible tube) and a tube into the affected area. Before the sialoplasty procedure can be carried out, a diagnostic sialography will be performed to assess the location and extent of the condition requiring the procedure. Diagnostic sialography is an imaging technique, in which the interventional radiologist injects contrast medium into the affected salivary gland and then performs an X-ray.

During the sialoplasty, a flexible guidewire will be passed into the salivary duct and directed to the narrowed or blocked area. Using a dilator, wire retrievable basket or balloons, the interventional radiologist will then expand the narrowing of the salivary duct or extracts the stones (or both), thus relieving the cause of the condition.

Why perform it?

Interventional techniques can be used to remove stones or other causes of obstruction in the salivary glands, relieving the symptoms caused by the blockage. When stones form in the glands, patients may experience a range of symptoms including pain, swelling and infection.

It has been suggested that interventional techniques may not be a suitable treatment if the stone causing the blockage is too large. However, the number of reported cases of this is small, making it impossible to give firm recommendations for these techniques. On the whole, interventional procedures are considered safe and successful.

What are the risks?

Patients usually experience swelling following the procedure, but this does not last longer than 24-48 hours. Some patients experience a tingling sensation in the tongue, but this resolves itself with time.

The procedure carries risks of bleeding in the mouth (though this is self-limiting so does not need treatment), pain during the procedure and infection. Contrast dye may leak into the tissue around the vein in which the needle was placed, or the doctor may accidentally create a false passage (an unnatural passage leading off from a natural canal). However, these usually do not cause lasting effects. More serious complications include ductal tears or duct detachment, which may subsequently require removal of the gland.

Bibliography

1. Buckenham T M, George C D, McVicar D, Moody A R, Coles G S. Digital sialography: imaging and intervention, Br J Radiol. 1994; 67:524–529.
2. Brown JE et al. Minimally invasive radiologically guided intervention for the treatment of salivary calculi, Cardiovasc Intervent Radiol. 2002; 25:352-5.

What is sclerotherapy?

Sclerotherapy is a minimally invasive procedure which is used to treat abnormal or enlarged blood vessels, usually varicose veins. During the procedure, a solution (a special type of alcohol or foam) will be injected directly into the vessel, causing the vessel to collapse, re-routing the blood into healthier veins. The collapsed vein can eventually be reabsorbed into the body.

How does the procedure work?

You will be anaesthetised for the procedure. The interventional radiologist may take one of two approaches to performing the sclerotherapy. The first possible way to carry out the procedure is by inserting catheters into a blood vessel and then injecting a solution of 90% alcohol into the affected vein, causing the vein to become blocked. This is known as an endovascular approach.

The other way in which the interventional radiologist may perform the procedure is a percutaneous approach. For this approach, the interventional radiologist directly injects the solution into the selected vessel or vessels, usually guided by sonography.

Recently, other minimally invasive alternatives have been used as alternatives for patients undergoing sclerotherapy, such as laser or cryoablation.

Why perform it?

Sclerotherapy is recommended as a treatment as it has a higher rate of success than other methods.

What are the risks?

There are a number of severe risks associated with this procedure. The substance used in the procedure may extend into other veins, or the patient may experience pain if the level of anaesthesia is insufficient. If the interventional radiologist uses a percutaneous approach, damage to the skin is possible.

Bibliography

1. Rabe E, et al. European guidelines for sclerotherapy in chronic venous disorders. Phlebology. 2013 Apr 4.

2. van der Vleuten CJ, Kater A, Wijnen MH, Schultze Kool LJ, Rovers MM. Effectiveness of Sclerotherapy, Surgery, and Laser Therapy in Patients With Venous Malformations: A Systematic Review. Cardiovasc Intervent Radiol. 2013 Nov 7.

What is SIRT?

SIRT is a radiation treatment for cancer. In this procedure, a radiation source called yttrium-90 is administered in small beads delivered through the blood stream into the organ affected by cancer.

How does the procedure work?

First the interventional radiologist will map out the blood vessels of the organ, and may block some of them to ensure the spheres only go to the tumour. Once this is done, a catheter (small tube) is placed inside a blood vessel that goes directly to the organ affected by cancer. The interventional radiologist will guide the catheter close to the tumour and then will administer the specially prepared beads that contain the radiation. When the beads land in the tumour, they emit a form of radiation energy that kills the cancer cells over a short distance around the bead.

Why perform it?

The aim of the procedure is to cure or slow the growth of cancer. It may be performed alone or in combination with conventional therapies. It is typically used to treat cancers located in an organ, most commonly the liver. It is a local therapy, meaning it only treats cancer cells near where it is administered. Usually it is used for tumours in solid organs that cannot be treated by other means alone, though it may be used together with conventional surgery and chemotherapy.

What are the risks?

There is a risk that the blood vessel will be injured or bruised while the tube is being placed. If the beads travel to normal tissues, these tissues will be killed. When the tumour is killed, you may experience pain, fever and nausea. In unusual cases, the treated area can become infected which may require medication or another intervention.

Bibliography

1. Theysohn JM, Muller S, et al. Selective internal radiotherapy (SIRT) of hepatic tumors: how to deal with the cystic artery. Cardiovasc Intervent Radiol 2013; 36(4):1015-1022.
2. Theysohn JM, Schlaak JF, et al. Selective internal radiation therapy of hepatocellular carcinoma: potential hepatopulmonary shunt reduction after sorafenib administration. J Vasc Interv Radiol 2012; 23(7):949-952.
3. Ray CE Jr, Battaglia C, et al. Interventional radiologic treatment of hepatocellular carcinoma-a cost analysis from the payer perspective. J Vasc Interv Radiol 2012; 23(3): 306-314.

What is thoracic endovascular aortic repair (TEVAR)?

The aorta is the largest vessel in your body and carries the blood away from your heart to the rest of your organs. A thoracic aneurysm occurs if the arterial wall below your rib cage weakens and develops a bulge, meaning blood is flowing into the weakened area.

The TEVAR procedure involves the placement of a covered stent (a metal mesh tube with a layer of fabric) into the weakened area of the artery. This provides a route for the blood to flow without pooling in the bulge.

Why perform it?

If you have an aneurysm, it should be monitored by your doctor. It is recommended that you undergo treatment for the aneurysm if it has a diameter of over 5.5 cm or if it has expanded by over 0.5 mm within a six-month period, to prevent the aneurysm from rupturing, causing death. If the aneurysm is causing symptoms such as high blood pressure, pain and abnormal bleeding, you may require treatment.

If the thoracic aneurysm was caused by trauma, such as if the patient was in an accident, TEVAR is a way to rapidly cover the injured area, controlling bleeding and preventing death.

Although surgical treatments for thoracic aortic aneurysms are available, surgery has a significantly higher risk of serious complications and death.

How does it work?

In most cases, the patient is given an epidural and a local anaesthetic for the procedure, although in some cases the patient is given a general anaesthetic.

The interventional radiologist will make a small cut in an artery at the top of your legs and will insert a sheath (a short tube to maintain safe access to the vessels). Then, the interventional radiologist will insert guidewires and catheters (thin flexible tubes) and direct them to the affected area under fluoroscopy. A contrast medium (dye) will be injected into the thoracic aorta so that the area clearly shows up under imaging for maximum accuracy. To place the stent, the interventional radiologist will insert it over a guidewire and move it to the correct location, where it will expand to seal the aneurysm or cover any leaks in the wall of the vessel.

After the procedure, your vital signs will be monitored and you will stay in hospital for 2-3 days. You may experience bruising and pain, though this can be treated with standard painkillers. Moving around once you are able to do so is encouraged. You will need to have the stent regularly checked using CT or ultrasound to ensure that the stent is in good condition and to avoid long-term problems.

What are the risks?

The rate of successfully placing the stent and covering the aneurysm or tear is 98-99%. There are lower rates of pain and serious complications than with surgery, but the main risks associated with TEVAR are the stent moving to another area of the body and blood collecting in the aneurysm again. This means that you will require regular monitoring, so that if any problems do occur, they can be resolved as soon as possible.

Minor complications include the risk of bruising and infection. There are some serious complications associated with the procedure, including death, stroke, tissue death, limb loss and injury to the kidneys. The rate of serious complications is estimated to be less than 15%, and the risk of death during the procedure is less than 1.5%, which is nearly three times lower than the risk of dying during open surgery (around 4.5%). There is also the possibility of the thoracic aorta tearing during the procedure, and in rare cases the spinal cord is injured, causing paralysis. Some patients react to the iodine in the dye used for imaging, which can affect the kidneys.

Bibliography

1. Aneurysmal disease: thoracic aorta. Hoel AW. Surg Clin North Am. 2013 Aug; 93(4):893-910, ix. doi: 10.1016/j.suc.2013.05.001
2. Endovascular stent-graft placement or open surgery for the treatment of acute type B aortic dissection: a meta-analysis. Zhang H, Wang ZW, Zhou Z, Hu XP, Wu HB, Guo Y. Ann Vasc Surg. 2012 May; 26(4):454-61. doi: 10.1016/j.avsg.2011.09.004.
3. Endovascular aortic repair versus open surgical repair for descending thoracic aortic disease a systematic review and meta-analysis of comparative studies. Cheng D, Martin J, Shennib H, Dunning J, Muneretto C, Schueler S, Von Segesser L, Sergeant P, Turina M. J Am Coll Cardiol. 2010 Mar 9; 55(10):986-1001. doi: 10.1016/j.jacc.2009.11.047. Review.
4. Thoracic Endovascular Aortic Repair (TEVAR) for the treatment of aortic diseases: a position statement from the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC), in collaboration with the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Grabenwöger M, Alfonso F, Bachet J, Bonser R, Czerny M, Eggebrecht H, Evangelista A, Fattori R, Jakob H, Lönn L, Nienaber CA, Rocchi G, Rousseau H, Thompson M, Weigang E, Erbel R. Eur Heart J. 2012 Jul; 33(13):1558-63. doi: 10.1093/eurheartj/ehs074.

What is an endovascular thrombectomy?

An endovascular thrombectomy is the removal of a thrombus (blood clot) under image guidance. A thrombectomy is most commonly performed for an arterial embolism, which is an arterial blockage often caused by atrial fibrillation, a heart rhythm disorder. An arterial embolism causes acute limb ischaemia (restricted blood supply) which leads to pain in the affected area. A thrombectomy can also be used to treat conditions in your organs, such as in your liver or kidney.

Your doctor may recommend that you have a thrombectomy as a treatment for stroke or for mesenteric ischaemia, where the blood flow in your small intestine is restricted due to inflammation or injury.

How does the procedure work?

The interventional radiologist will insert a 3 mm plastic tube (called a sheath) into the base of your skull or your groin. They will guide the sheath to the blood clot.

There are a number of different techniques for this procedure. The blood clot can be removed using a vacuum to suck the thrombus out, or mechanical equipment to break up the clot, or with clot using saline jets or ultrasound waves.

The devices for these techniques are inserted over the sheath into the affected artery. You may also need additional catheter thrombolysis, a procedure in which clot-dissolving medication is delivered to the clot under X-ray imaging.

A combined treatment using both thrombectomy and thrombolysis can continue over 24-48 hours with several follow-ups using angiography at regular intervals.

Why perform it?

An interventional thrombectomy is used to remove the blood clot and to avoid a permanent blockage in the vein or artery which would prevent blood flow to a limb or an organ, causing acute symptoms of pain, lack of a pulse, paleness, paraesthesia (when a limb ‘falls asleep’) and paralysis, as well as the possibility of permanent complications such as the death of tissue cells in your body.

A thrombectomy is often combined with other treatments, such as treatment to stop blood clots forming or thrombolysis, which involves using medication to break the blood clot down and is followed by strict observation for 24-48 hours.

You will also be treated for the underlying condition which caused the arterial thrombus, such as a heart rhythm disorder or a small blood clot caused by deep venous thrombosis.

What are the risks?

Minor risks include the risk of bruising at the puncture site in the neck or groin or in the affected limb. Major risks include the risk of the blood clot travelling deeper into the artery or vein or an injury to the affected area during the treatment.

In rare cases, patients experience bleeding in the skull as a result of the combined thrombectomy and thrombolysis – if this occurs, the treatment must be stopped immediately.

Bibliography

1. Ansel GM, George BS, Botti CF, McNamara TO, Jenkins JS, Ramee SR, et al. Rheolytic thrombectomy in the management of limb ischemia: 30-day results from a multicenter registry. Journal of endovascular therapy: an official journal of the International Society of Endovascular Specialists. 2002; 9(4):395-402.
2. Allie DE, Hebert CJ, Lirtzman MD, Wyatt CH, Keller VA, Khan MH, et al. Novel simultaneous combination chemical thrombolysis/rheolytic thrombectomy therapy for acute critical limb ischemia: the power-pulse spray technique. Catheterization and cardiovascular interventions: official journal of the Society for Cardiac Angiography & Interventions. 2004; 63(4):512-22.
3. Kasirajan K, Gray B, Beavers FP, Clair DG, Greenberg R, Mascha E, et al. Rheolytic thrombectomy in the management of acute and subacute limb-threatening ischemia. Journal of vascular and interventional radiology: JVIR. 2001; 12(4):413-21.
4. Kasirajan K, Haskal ZJ, Ouriel K. The use of mechanical thrombectomy devices in the management of acute peripheral arterial occlusive disease. Journal of vascular and interventional radiology: JVIR. 2001; 12(4):405-11.
5. Wagner HJ, Muller-Hulsbeck S, Pitton MB, Weiss W, Wess M. Rapid thrombectomy with a hydrodynamic catheter: results from a prospective, multicenter trial. Radiology. 1997; 2 05(3):675-81.

What is thrombolysis?

Thrombolysis is a procedure which uses medication to dissolve a blood clot. The medications used in thrombolysis are called thrombolytic agents.

Thrombolysis is most commonly performed to treat a blood clot in the lower limbs, which causes acute limb ischaemia (restricted blood flow in the affected limb), leading to pain in affected area. It can also be used to treat blood clots in organs such as the liver or kidney, as well as treating restricted blood flow in the small intestine due to inflammation or an injury, massive pulmonary embolism (a blood clot in main artery of a lung) or stroke.

How does the procedure work?

The interventional radiologist will insert a 3 mm plastic tube (called a sheath) into the base of your skull or your groin and will guide the sheath to the blood clot.

Thrombolysis is performed using medications which prevent blood clots from growing (known as lytic substances), which are administered via a catheter into the thrombus. Catheters designed to be used in this treatment have lots of tiny holes. This means that the distribution of lytic substances can be spread out across the catheter and have maximum effect.

Why perform it?

Thrombolysis is performed to remove the blood clot and to prevent the vein or artery from becoming permanently blocked and restricting blood flow to a limb or organ. Restricted blood flow leads to acute symptoms of pain, a lack of pulse, paleness, paraesthesia (when a limb ‘falls asleep’) and paralysis, as well as the possibility of permanent complications such as tissue necrosis (the death of tissue cells in your body).

You will probably also need medication to prevent blood clots forming as well as a thrombectomy, for which you will be under strict observation for a 24-48 hours with several angiographic follow ups.

You will also be treated for the underlying condition which caused the thrombus, which may be a heart rhythm disorder or a small blood clot caused by deep venous thrombosis.

What are the risks?

Minor risks include the risk of bruising at the puncture site in your neck or groin, or in the affected limb.

The major risks tend to be due to the devices used in the procedure, such as the risk of the blood clot travelling deeper into the artery or vein or an injury to the affected area during the treatment.

In rare cases, the patient experiences bleeding in the skull due to the thrombolysis – if this occurs, the treatment will be stopped immediately.

Bibliography

1. Results of a prospective randomized trial evaluating surgery versus thrombolysis for ischemia of the lower extremity. The STILE trial. Annals of surgery. 1994; 220(3):251-66; discussion 66-8.
2. Berridge DC, Kessel D, Robertson I. Surgery versus thrombolysis for acute limb ischaemia: initial management. Cochrane Database Syst Rev. 2002(3):CD002784.
3. Comerota AJ, Weaver FA, Hosking JD, Froehlich J, Folander H, Sussman B, et al. Results of a prospective, randomized trial of surgery versus thrombolysis for occluded lower extremity bypass grafts. American journal of surgery. 1996; 172(2):105-12.
4. Fox D, Ouriel K, Green RM, Stoughton J, Riggs P, Cimino C. Thrombolysis with prourokinase versus urokinase: an in vitro comparison. Journal of vascular surgery. 1996; 23(4):657-66.
5. Ouriel K, Veith FJ, Sasahara AA. A comparison of recombinant urokinase with vascular surgery as initial treatment for acute arterial occlusion of the legs. Thrombolysis or Peripheral Arterial Surgery (TOPAS) Investigators. The New England journal of medicine. 1998; 338(16):1105-11.

What is TIPS?

A shunt is an artificial passage which allows fluid to move from one part of your body to another. A transjugular intrahepatic portosystemic shunt (TIPS) connects the vein which brings blood from your gastrointestinal tract and intra-abdominal organs to your liver, and the vein from your liver to the right part of your heart.

How does the procedure work?

You will be conscious but sedated for the procedure, which the interventional radiologist will carry out using fluoroscopy and ultrasound for guidance.

The interventional radiologist will puncture your jugular vein on the right side of your neck with a needle and will then insert a vascular sheath over a wire into the inferior vena cava. They will explore the hepatic vein with a catheter designed for this purpose.

The interventional radiologist will puncture the portal vein through the liver with a special needle and position a wire between the two veins. After the area has been dilated, a stent or stent graft will be placed between the portal and hepatic vein to create a lasting connection.

Why perform it?

The TIPS procedure is usually performed in patients with liver cirrhosis. If you have this condition, your normal blood flow through the liver is blocked by scar tissue within the liver, which increases the pressure in your portal vein.

The increased pressure in your portal vein makes thin veins in your gullet or stomach become abnormally enlarged and so at risk of bleeding. Another symptom of liver cirrhosis is an abnormal collection of fluid (ascites) in the abdominal cavity.

You may be advised to undergo TIPS if you have varices which bleed acutely or recurrently and have not responded to other treatments.

Once the interventional radiologist has placed the shunt, the pressure in the portal vein decreases, protecting the area from bleeding and reducing the ascites.

What are the risks?

Because a liver suffering from cirrhosis is shrunken and the liver tissue can be very hard, it is possible to puncture the outside of the liver. This can cause bleeding which requires further treatment.

Another risk is that after the TIPS procedure ammonia from the intestine might bypass the liver and be delivered to the brain, which may result in a condition called hepatic encephalopathy, the symptoms of which range from mild (alterations in thinking) to severe (confusion and coma).

Due to the shunt, there is an increased amount of blood flowing directly to the heart, which can cause heart failure. If you experience this, your doctor will decrease or disrupt the blood flow through the TIPS.

Bibliography

1. Krajina A, Hulek P, Fejfar T, Valek V. Quality improved guidelines for transjugular portosystemic shunt (TIPS). Cardiovasc Intervent Radiol 2012; 35:1295-1300.

What is the endovascular treatment of AV fistula graft malfunction?

An AV fistula is an abnormal connection between an artery and a vein, and is sometimes surgically created to help with haemodialysis treatment. In these cases, a shunt graft is inserted to aid the treatment.

Unfortunately, sometimes the shunt will fail, known as graft malfunction. If you experience this, your doctor may recommend that you have endovascular treatment. The aim of this minimally invasive procedure is to stop narrowing of the fistula and remove any blockages from the shunt, such as blood clots.

The techniques used in the procedure depend on the type of lesion as well as its location.

How does the procedure work?

The interventional radiologist will usually enter the AV fistula through a direct puncture into the shunt, though they may instead choose to enter through a puncture in your elbow flexure or in your groin. The interventional radiologist will choose the entry point and technique depending on the condition which needs to be treated (such as narrowing of the fistula or a blood clot in the shunt) and its location.

If you have a narrowing of the AV fistula, the interventional radiologist may perform a technique called percutaneous transluminal angioplasty (PTA), which involves inserting and expanding a balloon to widen the vessel.

In rare cases, such as if the AV fistula starts to narrow again (restenosis) or if the area has been injured during the procedure, the interventional radiologist may insert a metal mesh tube (a stent) into the fistula. This acts like a skeleton and keeps the vessel open by supporting the walls of the vein. You may also need to take medication to prevent blood clots forming, but this depends on the PTA, the stent and your clinical situation.

If you have a blood clot, it can be sucked out by a vacuum, or mechanical devices can be used to break it up. These devices are applied over the sheath into the thrombus.

These techniques may need to be followed by catheter thrombolysis, in which medication is inserted through a catheter to break up the thrombus. If you undergo combined therapy with a thrombectomy or thrombolysis, you will be kept under observation for 24-48 hours with repeated follow-ups using angiography.

Why perform it?

The endovascular treatment of AV fistula graft malfunction is recommended to prevent or reverse blockages and so restore the function of the AV fistula and shunt.

There are a number of techniques and tools which your interventional radiologist may use, depending on the problem. If you have a stenosis (narrowing), the best treatment option is a balloon which can be inserted and gently inflated, while if you have a blood clot, a combination of thrombectomy, thrombolysis and medication to prevent blood clotting may be recommended.

What are the risks?

Minor risks include bruising at the puncture site in your neck or groin or in the affected limb. Major risks include injury to the wall of the blood vessel, which can happen if the devices are used incorrectly. You may experience bleeding if you undergo thrombolysis.

Bibliography

1. Beathard GA. Mechanical versus pharmacomechanical thrombolysis for the treatment of thrombosed dialysis access grafts. Kidney international. 1994; 45(5):1401-6.
2. Glanz S, Gordon DH, Butt KM, Hong J, Lipkowitz GS. The role of percutaneous angioplasty in the management of chronic hemodialysis fistulas. Annals of surgery. 1987; 206(6):777-81.
3. Gmelin E, Karnel F. Radiologic recanalization of veins, vascular prostheses and arteries in cases of insufficient dialysis fistulas. RoFo: Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin. 1990; 153(4):432-7. Radiologische Rekanalisation von Venen, Gefassprothesen und Arterien bei insuffizienten Dialysefisteln.
4. Keller E, Reetze-Bonorden P, Lucking HP, Bohler J, Schollmeyer P. Continuous arteriovenous hemodialysis: experience in twenty-six intensive care patients. Contributions to nephrology. 1991; 93:47-50.
5. Vorwerk D. Non-traumatic vascular emergencies: management of occluded hemodialysis shunts and venous access. European radiology. 2002; 12(11):2644-50.

What is ureteric stenting?

A ureteric stent (also called a J-J stent or double-J stent) is a thin, flexible plastic tube which is curled at both ends to avoid damaging the kidney and urinary bladder and to prevent it from dislocating. The stent is placed so that its upper end is in the kidney and its lower end is in the urinary bladder.

Ureteric stenting is the procedure in which stents are inserted into the ureter through the skin and via the kidney, to allow urine to pass from the kidney to the bladder.

How does the procedure work?

You will lie on your stomach, usually with one side slightly raised on a pillow, and will receive an injection of a painkiller and a sedative. The interventional radiologist will insert a needle through your skin and into your kidney under the guidance of ultrasound, X-ray or CT. If you already have a nephrostomy catheter in place, the interventional radiologist will use this as the entry point for the needle into the skin.

The interventional radiologist will use the needle to insert a wire, which is then used to guide a nephrostomy tube into your kidney, and a catheter, which is led through the ureter and into your bladder. At this stage, you may experience discomfort in your bladder. The interventional radiologist then places the J-J stent over the wire. You may also have a nephrostomy catheter placed in your kidney to drain urine externally.

A ureteric stent must be changed every three to six months. This is usually performed as an out-patient procedure.

Why perform it?

Ureteric stenting is performed when long-term urinary drainage is needed. The procedure is often more favourable than nephrostomy, which can have a larger effect on the patient’s quality of life.

What are the risks?

It is possible that you will experience minor bleeding from your kidney after the nephrostomy, though severe bleeding that requires treatment occurs in less than 5% of patients. In less than 1/500 patients an organ near the kidney is injured during the nephrostomy. Although temporary low-grade fever is common after the procedure, a high fever occurs in around 1-3% of patients, which is usually the result of an unresponsive infection.

What is vena cava stenting?

A stent is a metal mesh tube. Vena cava stents are designed for use in the superior vena cava (SVC), which transports deoxygenated blood from the upper part of the body back to the heart. In rarer cases they are used in the inferior vena cava (IVC), which carries the deoxygenated blood from the lower part of the body back to the heart.

Vena cava stenting is used to manage a stenosis (narrowing) or blockage in the vein, which is most commonly caused by a malignant (cancerous) tumour. The procedure may be recommended if you are in an emergency situation, but this depends on your clinical symptoms.

How does the procedure work?

The interventional radiologist will insert a 3 mm plastic tube (called a sheath) into the base of your skull or your groin. They will then guide the sheath near to the stenosis or blockage in the affected vein. The vein will be reopened using a metallic wire and a selective catheter using a technique called recanalisation, after which the vena cava stent is placed.

The stent is self-expanding and acts like a skeleton to keep the vena cava open. If your vena cava is completely blocked due to a tumour, your interventional radiologist may also insert a tiny balloon which inflates once it is in the vein before and after inserting the stent. You will need to take medication that prevents blood clotting for 1-2 weeks following the procedure; the exact time period depends on the type of stent used and your clinical situation.

Why perform it?

The aim of vena cava stenting is to manage symptoms caused by an obstruction of the blood flow in the vein, which is much more common in the SVC than in the IVC.

The main symptom of an obstructed blood flow in the vena cava is shortness of breath, followed by swelling of the face, neck or arms, a headache, a cough and enlargement of the veins in the neck, chest and arms. You may experience other symptoms but they are rare.

Your symptoms should stop within 48 hours of the stent placement.

What are the risks?

There are some minor risks, including the risk of infection and bruising at the puncture site in your neck or groin. Major risks include the risk of the stent accidentally going into the heart during placement, the development of a blood clot, or the stent later becoming blocked due to a tumour, though in this case the vessel can be reopened in a second intervention.

Bibliography

1. Nagata T, Makutani S, Uchida H, Kichikawa K, Maeda M, Yoshioka T, Anai H, Sakaguchi H, Yoshimura H. Follow-up results of 71 patients undergoing metallic stent placement for the treatment of a malignant obstruction of the superior vena cava. Cardiovasc Interv Radiol 2007; 30:959-967.
2. Rizvi AZ, Kalra M, Bjarnason H, Bower TC, Schleck C, Gloviczki P. Benign superior vena cava syndrome: stenting is now the first line of treatment. J Vasc Surg 2008; 47:372-380.
3. Ploegmakers MJ, Rutten MJ. Fatal pericardial tamponade after superior vena cava stenting. Cardiovasc Intervent Radiol. 2009 May; 32(3):585-9.
4. Albers EL, Pugh ME, Hill KD, Wang L, Loyd JE, Doyle TP. Percutaneous vascular stent implantation as treatment for central vascular obstruction due to fibrosing mediastinitis. Circulation. 2011 Apr 5; 123(13):1391-9.

What is a venous access port?

A venous access port is a central venous access device that allows doctors to easily access your veins to give treatments and to take blood. It is made of a non-irritant material and is designed to be inserted under your skin and remain in place for weeks or months. It is also known as a subcutaneous infusion port, and includes a catheter (a thin hollow tube), which is inserted through the skin and is then connected to a port in a pocket under the skin.

Venous access ports are commonly used in the care of patients with chronic liver disease, particularly cancer patients, and are considered an integral part of cancer therapy. The port provides reliable access for taking blood, blood transfusions and administering nutrition, fluids and medication with minimal disruption to the patient’s lifestyle. The venous access ports used today are light and can be used during imaging procedures.

How does the procedure work?

The procedure for implanting a venous access catheter is performed on an out-patient basis, under fluoroscopic guidance. In most cases, the port is inserted into the patient’s upper chest or arm. The interventional radiologist will access the vein under ultrasound guidance using a thin needle. The right internal jugular vein, which collects blood from your brain, face and neck, is the preferred vein for this as the risk of blood clots and pneumothorax (collection of air or gas in the space between the lung and the chest wall) is lower.

Once the interventional radiologist has accessed the vein, they will use a guidewire to introduce a sheath and create a small pocket under the skin in the chest area. The catheter is then tunnelled to the vein and the port is connected to the catheter and placed in the pocket. Most physicians prefer to wait a week before starting to use the port. The wall of the port can be used for approximately 2000 punctures.

Why perform it?

The procedure is ideal for patients in need of long-term yet intermittent intravenous access. These patients typically receive chemotherapy or transfusions on a weekly or monthly basis and are unable to use a catheter inserted into a vein in the arm or hand.

Although the placement procedure is more complex and invasive than the more common technique of inserting a catheter into a vein in the hand or arm, central venous access ports reduce the restrictions on patient’s daily activities, such as bathing, swimming and other forms of exercise. A venous access port has a lower risk of being dislodged than a catheter in the arm or hand. The port also requires fewer injections of heparin and fewer dressing changes. Because it is beneath the skin, it has an aesthetic advantage as well as a decreased risk of infection. Although venous access ports are expensive, the maintenance costs and risk of infection are low.

What are the risks?

Early complications are related to the technique itself, such as bruising, pneumothorax, nerve injury and an abnormal connection developing between an artery and a vein (called an arteriovenous fistula). Complications that may occur after the procedure include infection, a blockage or fracture in the catheter, blood clots and blockages in the vein. Some of these complications can have serious consequences and may even lead to death.

If the catheter breaks or fractures, any medication in the catheter may leak under the skin, causing soft tissue death or wounds that do not heal. Complications are usually associated with the route of implantation, a lack of experience in the physician implanting the port, and if appropriate care is not taken with the catheters while they are in use.

If the venous access port is implanted under image guidance, the risk of procedure-related complications associated with surgical implantation is virtually eliminated.

What is selective venous sampling?

You may be recommended to undergo selective venous sampling if your doctor would like to find out more about your hormones. The procedure involves taking a sample of blood from a particular area of blood vessels, which is then analysed to see which substances the organs and tissues around it have produced.

The organs most frequently analysed in this procedure are the adrenal glands, the parathyroid glands and pancreas.

How does the procedure work?

The interventional radiologist will insert a 2-3 mm catheter (tube) into a blood vessel in your groin and will then use imaging to guide the catheter to the selected area of veins. The interventional radiologist then takes some samples of blood from these veins, which are immediately analysed to check the levels of particular hormones and other substances.

Why perform it?

Selective venous sampling is performed when it is suspected that a patient has a tumour but the doctors have been unable to find it using imaging, usually because the tumour is too small. The procedure allows surgeons to know precisely where the tumour is due to the level of hormones and other substances in the blood.

What are the risks?

Minor risks include bruising to your groin. More significant risks include the possibility of injuring a vein during the procedure, but the risk of this is very low.

Bibliography

1. Viste K, Grytaas MA, Jørstad MD, Jøssang DE, Høyden EN, Fotland SS, Jensen DK, Løvås K, Thordarson H, Almås B, Mellgren G. Efficacy of adrenal venous sampling is increased by point of care cortisol analysis. Endocr Connect. 2013 Nov 15; 2(4):236-42.
2. Sarlon-Bartoli G, Michel N, Taieb D, Mancini J, Gonthier C, Silhol F, Muller C, Bartoli JM, Sebag F, Henry JF, Deharo JC, Vaisse B. Adrenal venous sampling is crucial before an adrenalectomy whatever the adrenal-nodule size on computed tomography. J Hypertens. 2011 Jun; 29(6):1196-202.

What is a vertebral augmentation?

Percutaneous vertebroplasty is a minimally invasive procedure in which cement designed for use in bones is injected into the vertebral column (spine).

You may be recommended for this procedure if you are suffering from pain caused by a vertebral compression fracture. This means that a vertebra (part of your spine) has collapsed, possibly due to a fall or the weakening of the vertebra. The cement functions as a sort of internal cast, providing pain relief and stabilising the affected area of the spine.

Kyphoplasty is when balloons are inserted into the compressed vertebra under CT or fluoroscopic guidance. If you have suffered a fracture due to trauma or have significant height loss caused by a fracture, your doctor may recommend that you undergo kyphoplasty.

Vertebral augmentation is used to restore height by introducing an artificial vertebra. This may be followed with the injection of bone cement for the treatment of painful vertebral fractures, especially ones caused by trauma or entailing a significant loss of height.

How does the procedure work?

Vertebroplasty and kyphoplasty are usually out-patient procedures. However, they are occasionally performed under general anaesthetic, and in these cases patients are kept in hospital overnight.

You will lie on your stomach and will be given a local anaesthetic. The interventional radiologist will insert a needle into the spine using X-rays (sometimes combined with CT) to guide the needle, and will inject bone cement to the targeted area to make sure the bone does not collapse again.

During the kyphoplasty procedure, two balloons are inserted and inflated before the injection of the bone cement, while, in the other vertebral augmentation procedures mentioned above, an implant is expanded before being inserted into the vertebral area.

If you are given a local anaesthetic, you will be kept in hospital for two hours after surgery to be monitored before being discharged.

Why perform it?

Vertebral augmentation can be performed to ease back pain which is caused by vertebral compressive fractures. Vertebral fractures are a common cause of pain and disability and are associated with increased mortality.

What are the risks?

A large number of studies have found vertebral augmentation to be an effective and safe way to treat vertebral fractures, especially when high-quality image guidance is used.

You may experience minor complications such as an infection, an allergic reaction or bleeding from the puncture site. You may also experience the accidental blockage of a vein in your lower back, small cement leaks in the soft tissue around the vertebrae, inflammation of part of the spinal nerve, or a small blockage in your lung.

Unfortunately, there are a number of possible severe side effects, though these are rare. Severe side effects include cement leaks into the surrounding area (a condition which requires immediate surgery), spinal cord direct lesion, which can lead to disability, and a large blockage in the lung, which can cause acute respiratory failure and death.

Flow chart for patients

Bibliography

1. Baerlocher MO, Saad WE, Dariushnia S, Barr JD, McGraw JK, Nikolic B; Society of Interventional Radiology Standards of Practice Committee. Quality Improvement Guidelines for Percutaneous Vertebroplasty. J Vasc Interv Radiol. 2013 Nov 14.
2. Gangi A, Sabharwal T, Irani FG, Buy X, Morales JP, Adam A; Standards of Practice Committee of the Society of Interventional Radiology. Quality assurance guidelines for percutaneous vertebroplasty. Cardiovasc Intervent Radiol. 2006 Mar-Apr; 29(2):173-8.

What is women’s health?

The term “women’s health” refers to conditions specific to the human female anatomy, including menstruation, maternal health and cancers affecting breasts and the female reproductive system.

Interventional radiology procedures can be used to treat a number of these conditions, meaning that some of the common causes of female infertility can now be treated without surgery. Often, these treatments do not require hospitalisation or general anaesthesia and patients can resume their normal activities shortly after the procedure.

Minimally invasive treatments may also be an alternative to procedures such as hysterectomy, meaning that these procedures can help preserve fertility. This page will highlight two minimally invasive treatments for conditions that affect women, but interventional radiology can be used to treat many other conditions.

Interventional radiology can be used to treat blockage of the fallopian tubes, a cause of infertility. The procedure to treat this condition is called fallopian tube recanalisation.

Interventional radiology can also be used to treat fibroids, which cause many women pain and discomfort. Patients with this condition can be treated using a technique called uterine fibroid embolisation.

What are the treatment options available?

Fallopian tube recanalisation is a minimally invasive procedure in which blocked fallopian tubes are re-opened using microcatheters (very fine, flexible plastic tubes that are visible under X-ray) and microguidewires (thin and flexible wires over which a microcatheter can be inserted into the body), which the interventional radiologist places into the vagina and cervix.

The microcatheter is inserted through the fallopian tube over a microguidewire. This clears any blockages in the fallopian tubes and restores the connection between the uterus and the abdominal cavity. This procedure is also used to treat infertility caused by a blockage in the fallopian tubes.

Uterine fibroid embolisation aims to treat fibroids by preventing blood flow to the vessels which supply the fibroids whilst preserving blood flow to the surrounding areas. The interventional radiologist will usually insert a 2-3 mm catheter (tube) into a blood vessel in your groin and will use image guidance to guide the catheter to each uterine artery (right and left). They will then inject microparticles (resin particles smaller than a grain of sand) into the uterine arteries to stop blood flow to the fibroids.

Interventional radiology can be used to ease discomfort and restore fertility for certain conditions. Because these procedures are less invasive than surgery, they carry fewer risks and allow patients to resume normal activity sooner than if they had undergone open surgery.

What is Y-90 radioembolisation?

Y-90 radioembolisation is a palliative treatment for primary liver lesions and liver metastatic disease which uses ionising radiation to shrink tumours. It is generally used to relieve the symptoms of liver tumours rather than to cure the underlying condition.

The liver has two sources of blood supply: the hepatic artery and the portal vein. Liver tumours tend to rely on the hepatic artery for their blood supply.

During a radioembolisation procedure, an interventional radiologist injects microspheres filled with the radioactive isotope yttrium (known as Y-90) into the vessels feeding the tumour. Because the radiation is focused only on the tumour, higher and more effective radiation doses can be used compared to other treatments.

How does the procedure work?

Depending on your individual situation, you may be given the procedure as an out-patient or you may require hospital admission following the treatment. The interventional radiologist will carry out the procedure using fluoroscopic guidance.

You will be given a local anaesthetic. After this, the interventional radiologist will insert a catheter (a thin tube) and a guidewire into an artery. You will then have some images taken of your upper abdominal arteries to show the exact location of the vessels feeding the tumour. The interventional radiologist will then insert microspheres filled with Y-90 into these vessels to deliver a high dose of radiation to the cancer cells. This radiation dose will decrease over the following two weeks.

Your vital functions will be monitored during the procedure. You may be given antibiotics to prevent infection, and, if necessary, IV analgesics or medication to prevent nausea.

Why perform it?

If you have an inoperable liver tumour or if you are not fit for surgery, you may benefit from Y-90 radioembolisation. Y-90 is beneficial for hepatocellular carcinoma (the most common type of cancer) affecting the portal vein of the liver, or if you have not responded to chemoembolisation.

Because the radiation dose is delivered directly to the tumour, the dose is higher than in standard radiation therapy and there are fewer possible complications. Radioembolisation can extend the patient’s life expectancy from months to years, as well as improving quality of life. In some patients, this procedure enables them to undergo surgery or liver transplantation.

What are the risks?

Y-90 radioembolisation is a relatively safe procedure. The most common complication is post-radioembolisation syndrome, which occurs in around 50% of patients. Symptoms include fatigue, low-grade fever, nausea, vomiting and abdominal discomfort.

Less common complications include a build-up of fluid, high levels of alkaline phosphatase and infection. You may also experience stomach ulcers, inflammation of the pancreas, raised blood pressure, gallbladder inflammation or pneumonia. As with all percutaneous procedures, there is a risk of bleeding or damage to a blood vessel.

In some cases, patients react to the iodinated contrast materials used in the procedure, experiencing allergic reactions and harmful effects on the kidneys.

Bibliography

1. Mahnken AH, Spreafico C, Maleux G, Helmberger T, Jakobs TF. Standards of practice in transarterial radioembolization.  Cardiovasc Intervent Radiol. 2013 Jun; 36(3):613-22.
2. Kennedy A, Nag S, Salem R, Murthy R, McEwan AJ, Nutting C, Benson A 3rd, Espat J, Bilbao JI, Sharma RA, Thomas JP, Coldwell D. Recommendations for radioembolization of hepatic malignancies using yttrium-90 microsphere brachytherapy: a consensus panel report from the radioembolization brachytherapy oncology consortium.  Int J Radiat Oncol Biol Phys. 2007 May 1; 68(1):13-23.