Interventional Radiology (IR) is a branch of medicine that specialises in minimally invasive surgery as an alternative to open surgery. These procedures are usually performed with pinhole access into the skin, which comes with some advantages. Some of the benefits from IR surgeries are day case procedures, local anaesthesia and sedation, a minor or almost invisible scarring, early recovery, mobilisation and discharge post-surgery, usually the same or the following day. These surgeries utilise new and advanced techniques and are as effective when compared to conventional open surgeries.
These procedures are performed by specialist doctors called Interventional radiologist. An Interventional radiologist is a physician who is dual-trained in both Clinical radiology and Interventional radiology. A clinical radiologist is a doctor certified to interpret and report X-ray films, ultrasound examinations, Computed Tomography (CT) imaging, fluoroscopy and magnetic resonance imaging (MRI). An interventional radiologist is a doctor who is certified to perform minimally invasive surgery and are involved in surgical care before and after the procedure.
Dual training in both imaging and surgery places the IR physician in a unique position that enables him/her to provide the most innovative minimally invasive treatment options to specific disease conditions. There are no areas within hospital medicine that an interventional radiologist is not associated with, as you will see in the list of procedures performed by IR in the next section. These are examples of some of the most common procedures performed by IR and can be broadly classified as follows –
Vascular Interventional Radiology (VIR) procedures.
VIR deals with diseases affecting the blood vessels (arteries, veins, lymphatics and Arterio-venous malformations (AVM)). Lymphatics channels are true blood vessels. VIR also includes surgeries where blood vessels are used as the port of entry to treat the various benign and malignant condition with the body’s organs.
A. Arterial disease: This blood vessel takes blood from the heart to an organ or limb. The conditions of the arteries include
- Atherosclerosis: A process of hardening of the blood vessels from cholesterol accumulation and inflammation which, results in either narrowing or blockage of a blood vessel, compromising blood supply to an organ or limb. These conditions are treated with balloon angioplasty (stretching the areas with a temporary balloon) and sometimes require stent implantation. A stent is a cylindrical mesh that looks like chicken wire- used as a scaffold to keep the blood vessel open. Atherosclerosis can affect any blood vessel such as that of the brain, organs (bowel, kidneys), arms and legs.
- Aneurysms: In this condition, there is an abnormal enlargement of a blood vessel like a balloon. A ruptured aneurysm can be fatal. These can be treated with a stent-graft (similar to stent but has a fabric covering) if it affects large and medium-sized blood vessel. Embolisation coils (special metal spring-like substances) can be used in small size vessels.
- Dissection: A dissection is a condition where the blood vessel splits in half on the inside along the blood vessel’s length. This can happen with severe hypertension (or high blood pressure) and trauma. These are extreme conditions that can be treated with stent-grafts.
- Bleeding: IR physicians are specifically trained to stop life-threatening internal bleeding from an organ or limb. Traditionally, these would be treated with open surgery. Some of the conditions that can cause internal bleeding are trauma, rupture of aneurysms, bleeding from the bowel, bleeding from the lungs, etc.
- Thrombosis: This is a condition where a blood vessel blocks and can threaten survival. An example is a clot in the lungs where IR doctors can suck the clot out with special tubes attached to a vacuum pump. Along with vascular surgeons, IR doctors can provide comprehensive care for clots in the leg or organs.
B. Bening or malignant conditions treated via an artery
Embolisation is a technique where artificial substances (coils, particles, foam, glue) are used to block off blood vessels, some common procedures performed by IR doctors are –
- Uterine artery embolisation (UAE): This is a minimally invasive procedure performed to control uterine fibroid symptoms such as pain, bleeding or mass effect. A uterine fibroid is a benign tumour within the uterus. IR doctor uses tiny particles to block the blood vessels. These particles (a.k.a embolising agents) look like beads. However, you will need a magnifying glass or sometimes a microscope to see them.
- Prostate artery embolisation (PAE): This is a minimally invasive procedure performed to control symptoms from an enlarged prostate gland. This could include the inability to empty the urinary bladder, dribbling of urine and the urge to go to the toilet frequently. Particles are used to perform this procedure similar to the UAE procedure above.
- Trans-arterial chemoembolisation (TACE): This is a minimally invasive procedure performed to control the growth of liver tumours such as Hepatocellular carcinoma (HCC). This is a palliative procedure aimed at controlling the growth of HCC. Sometimes TACE can be used as an intermediate procedure while waiting for liver transplantation, a curative procedure for HCC.
- Embolisation of tumour metastasis: Small particles are used to block the blood vessels supplying a metastatic tumour ( a tumour that has spread to different areas such as bones), usually performed before a planned bone surgery.
C. Liver and kidney transplant Maintainance: This involves stretching the blood vessels that supply the transplanted organ to prevent the organ from failing.
Venous conditions: This blood vessel takes blood from the limb or organ back to the heart. These are the same blood vessels used to obtain a blood sample when you visit your doctor for a blood test. Some of the venous procedures performed by IR are –
- Vascular access: IR physicians can insert special tubes or catheters through a vein in the neck or the groin. These tubes are used for long term nutrition, long term antibiotics, dialysis etc. The most common examples are the Hickman line, Tessio line, PICC line, etc.
- Central venous occlusion (CVO) occurs in patients who have had multiple vascular access insertion episodes or a long-term indwelling vascular catheter. CVO is blockage of the prominent veins in the chest or pelvis, which can cause swelling of the face, arms or legs, respectively. The treatment involves angioplasty or stent implantation. In rare cases, the veins can be blocked from cancer when a stent is required.
- Thrombosis: This involves new painful blockage of the veins in the legs and sometimes the abdomen. Treatment can vary from oral medication to injection of clot-busting drugs, angioplasty and/or stent.
- Dialysis fistula creation: A fistula is an artificial communication between the artery and vein used to perform dialysis. A fistula is created with pinhole access, but this procedure may not be suitable for all patients. The advantage is less scarring and distortion of tissue planes. This procedure does not preclude traditional methods of open surgical fistula creation.
- Dialysis fistula Maintainance: IR physician maintains fistula created by vascular surgeons when they become inadequate for dialysis. This included balloon angioplasty and stent procedures.
- IVC filter insertion or removal: An IVC filter is an umbrella-like device usually placed within a large blood vessel in the abdomen called the Inferior vena cava to prevent blood clots from migrating from the legs to the lungs. These are usually implanted with temporary intent through the neck or the groin.
- Varicocoele: This is a condition where the blood vessels draining the testicles become enlarged due to a faulty on-valve system. A varicocele can result in pain, a dragging like sensation and fertility problems. The treatment involves the blockage of these abnormally enlarged veins with embolisation coils and or medical foam (STS).
- Pelvic congestion syndrome: This condition occurs in women who experience pain in the abdomen and pelvis with a dragging sensation. Pain can worsen during menses or sex and results from abnormally enlarged veins that drain the ovaries and the pelvic organs. A combination of coils and medical foam (STS) is used to treat this condition.
- Varicose vein embolisation. These are abnormally dilated blood vessels in the legs due to abnormality in the one way valve present within these veins. There are many treatments, and vascular surgeons usually provide the most. An IR physician is generally involved when there are abnormal connections between the veins in the pelvis and thigh, resulting in varicose veins in the legs. The IR doctor will aim to block off these connections with coils, usually from the neck or the groin.
- Transjugular Intrahepatic Portosystemic shunt (TIPSS): In this procedure, an artificial communication is created between the portal vein (blood drained from bowel and contains the digested nutrients en-route to the liver for clearing unwanted substances) and the hepatic vein (the veins of the liver which drains the liver to the heart. This communication is performed in liver cirrhosis patients who also present with the following conditions. Uncontrolled enlargement of the abdomen due to fluid accumulation and/or uncontrolled bleeding in the gullet or stomach, which cannot be treated with endoscopy.
- Portal vein embolisation: This procedure is performed in patients who are being planned for partial removal of the liver in conditions where only a part of the liver contains a tumour that has spread from the bowel. This procedure increases the size of the liver that is being left behind in the body (which does not have the tumour) and sustain life.
- Transjugular liver biopsy: This procedure involves obtaining a liver tissue sample from accessing the neck veins. This procedure is an alternative to securing liver tissue through the abdomen in patients who urgently need a tissue sample for diagnosis and either has too thin blood or has considerable volume fluid accumulation in the abdomen. Both these conditions increase the risk of bleeding post-biopsy if performed from the abdomen.
- Pulmonary AVM embolisation: There are rare and abnormal blood vessel connections in the lung, which can act as a conduit that can shunt clots from the lungs to the brain. These are blocked with embolisation coils or vascular plugs.
Arteriovenous malformations (AVM’s): These are rare conditions where there is an abnormal connection between the blood vessel and can affect any part of the body. These conditions result in pain, swelling, deformity, inability to use the limb etc. These are special surgeries that are performed with embolisation techniques.
Lymphatic conditions: These are rare disease where the ducts that drain the legs are abnormal or leaking, and IR specialities can perform special procedures to block off these leaky vessels.
Non-vascular intervention: These are procedures involving tubes other than the blood vessels, such as kidney tubes (tubes connecting the kidney and the bladder) or bile tubes (there are tubes within the liver that contain the bile). Other procedures include treating blockages of the gullet, small or large bowel or gall bladder. Some of the operations performed by IR physician are –
- Nephrostomy: This procedure involves the insertion of a small tube into a blocked kidney. A kidney can get blocked from stones or cancer. This procedure helps to divert the urine being produced by a blocked kidney and thereby preserve its function.
- Ureteric stents: These procedures are performed when kidney tubes are blocked either from cancer or stones. Sometimes, following pelvic surgery where the kidney tubes have been damaged. This helps to prevent the kidney from getting clogged.
- Biliary drain and biliary stent: This procedure is performed when the liver’s bile ducts are blocked from cancer or stones. The bile tubes are drained with a small plastic tube, and sometimes, a stent is required to keep it open.
- Cholecystostomy: This is a procedure where a small tube is inserted into the gall bladder inflamed (or infected) secondary to gallbladder blockage from stones. Most cases will be treated with traditional surgery, and a cholecystostomy will only be required in some particular cases.
- Chest drain: Insertion of a tube in the chest cavity under ultrasound or CT guidance to drain a collection (fluid, pus or air)
- Abscess or collection drain: This includes insertion of a tube in collections in different areas of the body (e.g. abdomen or pelvis) under ultrasound or CT guidance.
- Solid-organ biopsy involves obtaining a tissue sample for diagnosis from various organs such as liver, kidney, prostate, lung, etc.
- Oesophageal Stent: This procedure involves a metal scaffold implantation to open an obstruction in the gullet in conditions such as cancer.
- Colonic stent: This procedure involves a metal scaffold implantation to open an obstruction in the large bowel secondary to bowel cancer.
- Radiologically inserted Gastrostomy (RIG): This procedure involves inserting a feeding tube into the stomach from the abdomen under local anaesthesia and sedation.
- Tumour ablation: This is a special procedure where small tumours and some metastatic tumours are destroyed (burnt or frozen) using special needles inserted into the tumour with ultrasound or CT guidance.