Department of Radiology,
Lister Hospital,
Stevenage,
Herts SG1 4AB
Email: Dr. Amerasekera
Tel: 01438 781 028
Fax: 01438 781 176
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Interventional
What is interventional radiology?
Interventional radiologists are involved in the treatment of the patient, as well as the diagnosis of disease. They treat an ever-widening range of conditions inside the body by inserting various small instruments or tools, such as catheters or wires, with the use of various imaging techniques (Xray fluoroscopy, CT scanners, MRI scanners, ultrasound scanners). Interventional radiology offers an alternative to the surgical treatment of many conditions and can eliminate the need for hospitalization.
If you want any information about the interventional examination please contact the Radiologist performing the examination. Often contrast agents are used during these procedures. Contrast agents are radio-opaque substances which are introduced into the body by mouth, per rectum or by injection. Some patients are allergic to these contrast agents. if you are allergic to any substances or have asthma or hay fever it is very important that you mention this to the Radiologist.
The descriptions provided about the different investigations are for general information. They may vary according to the patients clinical problem. Please discuss your queries with the Radiologist performing the examination.
If you suffer from any allergies, asthma or hayfever please inform the Radiologist. If you have had a reaction to any injections please let us know. Those on tablets (Metformin) for their diabetes ask the Radiologist whether it is safe to proceed with the examination. We take great care to avoid reactions to contrast although reactions are rare. You are most welcome to speak to the Radiologist or the Radiographer if there are any queries. Phone: Lister 01438 781028 or Pinehill 01462-422822 If you are taking treatment for kidney or heart problems please let the Radiologist know and discuss this with your own Physician
What is Fine Needle Aspiration (FNA)?
Fine-needle aspiration is a way to check a mass or a lump when your doctor isn't sure what the cause is. A very small needle is put into the mass and gently moved back and forth while suction is applied. One or two drops of fluid are removed. The fluid is smeared on a slide and sent to a lab to be checked to see if the fluid has any cancer cells in it. Your doctor will get a report from the lab that tells about the mass. Then your doctor can decide what the next step should be. How accurate is fine-needle aspiration? No medical test is 100 percent accurate. But depending on several factors, including the size and location of the lump, fine-needle aspiration is about 90 percent accurate in diagnosing cancer.
Sometimes, an accurate diagnosis can't be made. This might happen if the fluid had too much blood or the mass had too much swelling. It also could happen if only a few cells were abnormal, or if the abnormal cells looked normal. It's very important to visit your doctor again after the procedure. You may need to have the mass removed or you may need another test. You may only need to see your doctor again a few weeks or months later. If your doctor decides not to remove the lump, you should check it regularly yourself so you can tell your doctor about any growth in the lump or change in the way it feels. Close follow-up is important to find the few cancers that aren't found by fine-needle aspiration. Isn't there any other way to check a mass?
The best way to check a mass is to have a pathologist look at a sample with a microscope. Fine-needle aspiration is one way to do this. Another good way to check a lump is a biopsy. A biopsy surgically removes all or part of the mass. Surgery has more complications and leaves a scar. Will the procedure hurt? No medical procedure involving a needle is painless. But the needles used in fine-needle aspiration are smaller than those used to do a blood test. So, it's usually not very painful. Are there any complications from fine-needle aspiration? Fine-needle aspiration has very few complications. The most common problem is a small bruise that usually goes away in a few days or weeks. Infection may occur, but it's rare.
Occasionally, a larger blood vessel or an organ near the lump may be penetrated by the needle. Can fine-needle aspiration spread cancer? Thousands of specimens have been taken by fine-needle aspiration. Only a few cases of cancer have been reported on the needle path. Cancer spread is not a risk of fine-needle aspiration. This information provides a general overview on fine-needle aspiration and may not apply to everyone. Talk to your GP or Consultant to find out if this information applies to you and to get more information on this subject.
Image Guided Biopsy
This consists of the placement of a biopsy needle through the patients skin into an organ of interest using imaging for guidance. The most commonly used imaging modalities are ultrasound (US),fluoroscopy and computer tomography (CT). Such a procedure is a minimally invasive method of obtaining tissue from the patient without the need for surgery. Whether or not the procedure is performed using ultrasound or CT for guidance the initial part of the examination is essentially the same. The patient has the procedure explained to them in detail and provides written and informed consent. Ultrasound,fluoroscopy or CT are used to determine the optimal site of entry for the needle through the skin and this area is cleaned and a local anesthetic is infiltrated into the soft tissue.
Typically, ultrasound procedures are fairly short and therefore it is not usually necessary for the patient to receive intravenous sedation with the examination being performed only under local anesthesia. CT procedures however tend to be a little longer in duration and may therefore in this instance receive intravenous sedation. Using ultrasound for guidance, the needle is placed into the region of interest and the direct ultrasound visualization and material is then obtained for analysis. If CT is used for guidance the needle is place into the lesion in stages with CT scans performed intermittently to ensure that the needle is indeed approaching the region of interest. At the end of the procedure the needle is removed from the patients abdomen and the procedure is complete. Usually patients will be transferred to an observation area where their vital signs will be assessed from anywhere between 2 to 4 hours following the examination to ensure there are no complications.
Liver biopsy
Liver biopsy is a diagnostic procedure used to obtain a small amount of liver tissue, which can be examined under a microscope to help identify the cause or stage of liver disease.The most common way a liver sample is obtained is by inserting a needle into the liver for a fraction of a second. This can be done in the hospital, and the patient may be sent home within 3-6 hours if there are no complications. The Consultant Radiologist determines the best site, depth, and angle of the needle puncture by physical examination or ultrasound. The skin and area under the skin is anesthetized, and a needle is passed quickly into and out of the liver. Approximately half of individuals have no pain afterwards, while another half will experience brief localized pain that may spread to the right shoulder. Another technique used for liver biopsy is guiding the needle into the liver through the abdomen or chest using various imaging techniques. This approach is used when there are localized tumors identified by ultrasound or computed tomography (CT). Either ultrasound or CT scanning is used to pinpoint the site of the tumor and guide the needle to this specific area through the abdomen or chest. After this procedure, the patient is usually allowed to go home the same day.Liver biopsy is often used to diagnose the cause of chronic liver disease that results in elevated liver function tests or an enlarged liver. It is also used to diagnose liver tumors identified by imaging tests. In many cases the specific cause of the chronic liver disease is highly suspected on the basis of blood tests, but a liver biopsy is used to confirm the diagnosis as well as determine the amount of damage to the liver. The primary risk of liver biopsy is bleeding from the site of needle entry into the liver, although this occurs in less than 1% of patients. Other possible complications include the puncture of other organs, such as the kidney, lung or colon. Biopsy, by mistake, of the gallbladder rather than the liver may be associated with leakage of bile into the abdominal cavity, causing peritonitis. Fortunately, the risk of death from liver biopsy is extremely low, ranging from 0.1% to 0.01%.
CT Scan Guided Biopsy of Lung
When there is a nodule or mass in the lung, a CT guided percutaneous needle biopsy is performed by the interventional radiologist to provide a microscopic diagnosis. A needle biopsy is less invasive and preferable to open surgical lung biopsy for this type of problem.The patient is placed on the CT scan table, preliminary scan of the nodule are obtained. The radiologist prepares the skin puncture site and injects local anesthesia into the skin. A biopsy needle is then introduced at the proper angle and depth into the nodule. Additional CT scans are taken to confirm good needle placement in the nodule. The biopsy sample is then taken. The major risk is that of an air leak or pneumothorax. Air leaks through the small needle puncture hole from the lung into a space between the lung and the inner chest wall called the pleural space. A small leak after lung biopsy is fairly common and they usually resolve on their own merely with overnight observation and serial chest x-rays to assess the size of the air leak. The other major risk is that of bleeding. Coagulation factors are checked before the procedure to avoid excessive bleeding.After the biopsy, a repeat CT scan or a Chest ray is done to monitor presence and size of the pneumothorax.
Image Guided Drainages
The ability to drain infected fluid collections (abscesses) percutaneously (through the skin) has represented one of the most significant developments in medicine in recent years. Prior to the development of percutaneous abscess drainage, it was invariably necessary for the patient to undergo major surgery in order that the infected fluid cavity be removed. With the ready availability of ultrasound and CT, most percutaneous abscess drainages are performed using one of these modalities for guidance of the needle and subsequently a catheter is introduced into the fluid collections for drainage.
Arteriogram of an Extremity
The extremities refer to the hands, arms, feet, and legs. An angiogram is an xray study of a blood vessel. Blood vessels are not normally seen by xray machines, so we use contrast agents to make blood vessels visible on xrays . X-rays are then taken of the blood flow through the extremity. Most often, angiography studies arteries, the vessels that carry blood from your heart to the body. Occasionally, angiograms are done of the veins, the vessels that carry blood from your body to the heart.
Preparation: Food and fluids will be restricted 6-8 hours before the test is done. You must sign a consent form. You will be given a gown to wear. You may be given a sedative or pain pill before the procedure.
Risks: Please ask the radiologist about the risks of the procedure.There are few risks to angiography and it is well known to be a safe test. There are rarely infections at the skin site of puncture which are readily treated with antibiotics. There is a small risk of bleeding at the site of puncture, called a hematoma which goes away with time. There is a very small chance of an allergic type reaction to the xray contrast dye ranging from hives to very rarely anaphylaxis and even death.
Procedure: This test is done in the hospital. You will be asked to lie on the Xray table. The area where the contrast medium will be introduced is shaved and cleansed. The site is usually in the leg. You are given a local anesthetic, the artery is punctured, and a needle is inserted into the artery. The catheter (a long, narrow, flexible tube) is inserted through the needle and into the artery. It is then threaded through until it is in the artery needed. This procedure is monitored by a fluoroscope (a special X-ray that projects the images on a TV monitor). The contrast medium is then injected into the artery, and the X-ray pictures are taken. The catheter is kept open by flushing it periodically with a saline solution containing heparin, which will keep the blood in the catheter from clotting. After the x-rays are taken, the needle and catheter are withdrawn. Pressure is immediately applied on the leg at the site of insertion for 10 to 15 minutes to stop the bleeding. After that time, the area is checked and a tight bandage is applied. The Xray table is hard and cold; you may ask for a blanket or pillow. There is a sting when the anesthetic is given. This does not numb the artery, so there will be brief, sharp pain as the catheter is inserted. There is a feeling of pressure as the catheter is advanced. As the dye is injected a burning or warm sensation occurs. There is often tenderness and bruising at the site of the injection after the test.
Angioplasty
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For certain relatively short stenotic lesions (narrowed segments of the vessel) which restrict blood flow, angioplasty is an ideal treatment. Newer guide wires and angioplasty balloons have been developed which make angioplasty technically easier and successful. The guide wire is advanced across the stenosis, an angioplasty balloon catheter advanced to the narrowed lesion, and the balloon inflated under flouroscopic observation. If all goes well, the vessel diameter is restored to normal and good, strong blood flow is restored to the extremity. Risks and complications: Angioplasty is a controlled stretching of the wall of the vessel and always involves some form of damage to the artery wall. Because the vessels undergoing angioplasty are usually very diseased to begin with, there is a risk that they will be made worse by the angioplsty. The inner layer of the vessel may rupture and may form a flap, which obstructs flow. This is called intimal dissection. If this happens, the vessel lumen can be restored with a metal stent.
Vascular Stenting
At present, stents can be used in the renal arteries, aorta, iliac arteries, femoral arteries. They are not recommended, yet, for superficial femoral arteries or in the carotid arteries unless part of an approved research study.
Thrombolytic Agents
The most commonly used agent is called Urokinase. This is a chemical agent, which was originally found in urine, which has the ability to dissolve blood clots. This agent can be delivered intra-arterially through a small caliber catheter or a hollow wire embedded directly in the clot obstructing the vessel. After about 24 to 48 hours of continuous infusion, the clot usually dissolves and flow is restored. After flow is restored any underlying stenosis in the vessel can be treated with balloon angioplasty or stent placement. Risks of thrombolytic therapy: Major risk is that of bleeding from the puncture site or occult internal bleeding.
Embolisation of Uterine fibroids
This is emerging as a safe and highly effective method for the treatment of symptomatic fibroids. For many years, interventional radiologists have employed percutaneous techniques to control traumatic and tumour related pelvic, abdominal and musculoskeletal hemorrhage. Today, these established techniques are being used to treat women with fibroids complicated by bleeding and pelvic pain. Percutaneous transcatheter uterine artery embolization of fibroids was first performed six years ago in France. It is now widely accepted worldwide as an alternative to myomectomy and hysterectomy.
The patient has to be first seen and assessed by a Consultant gynecologist. An ultrasound evaluation of the pelvis is obtained as a baseline. It is important to exclude pre-existing pathology such as infection, endometriosis, or cancer.
This examination is only carried out if the patent's Consultant Gynaecologist agrees this is the best form of treatment for her. Women who want to have children may not be candidates for the procedure.
The procedure is performed from the groin. Both uterine arteries are selected and arteriography performed. Bilateral embolization is accomplished with the injection of polyvinyl alcohol particles . All patients experience pelvic pain of variable severity. The majority of patients are hospitalized for less than 24 hours. A small number require hospitalization for up to three days for treatment of post-embolization syndrome. Most have gradual improvement in symptoms and return to work within one week. Published results indicate an 85% clinical success rate with no further therapy required.
Percutaneous Biliary Drainage
It is a procedure in which a catheter is placed through your skin and into your liver to drain bile, and is performed without surgery. An interventional radiologist, a specially trained doctor, performs this procedure in the Radiology Department. The doctor uses x-ray imaging (like a TV screen) to help place the catheter in the proper location.Blockage of the bile ducts is the most common reason for the biliary drain. Your liver makes bile, which aids in digestion. The ducts (which are tubes) normally carry bile form the liver to the bowel. If your ducts are blocked, the bile backs up into your liver. Some of the signs which may occur are jaundice (yellow skin color), dark urine, light stools, nausea, and poor appetite. Some people even experience severe itching. These symptoms can be relieved with a biliary drainage which gives the bile a pathway to exit the liver.
Percutaneous Stone Removal
For very large or hard stones which are located in the kidney, a percutaneous (through-the-skin) approach may be required to remove all of the stone material. A small cut is made in your back allowing placement of a telescope directly into the kidney. The stone can easily be seen and is ground up into small particles and removed using a special instrument which is passed through the telescope. Following this type of stone removal, you will have a small tube in your side during your hospital stay (a few days).The exact procedure varies according to the clinical problem.
Lumbar Facet Joint Injection
Lumbar facet joints are small joints a little larger than the size of the thumb nails located in pairs on the back of the spine. They provide stability and guide movement in the lower back. If the joints become painful they may cause pain in the lower back, abdomen, buttocks, groin or legs. A facet joint injection serves several purposes. First, by placing pain relieving medicine into the joint, the amount of immediate pain relief experienced will help confirm the source of pain. Additionally, the temporary relief of the analgesic may allow a physiotherapist to treat that joint. Also steroid injections will help to reduce any inflammation that may exist within the joint. During the procedure the patients are placed on the scanner table on their stomach. Radiologist can visualize these joints using the CT scanner. The skin on the low back is cleaned.The Radiologist numbs a small area of skin with local anaesthetic. This medicine stings for several seconds. After the local anaesthetic has been given time to be effective, the Radiologist directs a very small needle, using CT guidance into the joint. A small amount of contrast (dye) is injected to ensure proper needle position inside the joint space. Then, a small mixture of anesthetic and/or anti-inflammatory (corticosteroid) is injected. One or several joints may be injected depending on the location of the patients usual pain.This examination is usually done as an out-patient procedure and you will be allowed home after a short period of time.
Copyright © 2000 - Dr. Douglas Amerasekera