Interventional Radiology Procedures Overview

MRI Availability

• MRI is not widely used for guidance due to its high cost and the requirement for non-magnetic equipment.

Interventional Radiology Procedures

• Interventional radiologists perform a variety of procedures including angioplasty and stent insertion, ascitic tap, bursal injection, carpal tunnel ultrasound and injection, image guided lumbar epidural corticosteroid injection, and image guided liver biopsy.

Angioplasty and Stent Insertion

• Used to treat narrowing in an artery.
• Uses a balloon to stretch the artery open and improve blood flow.
• A metal stent acts as a scaffold to keep the artery open.
• Starts with an angiogram - a special type of X-ray image that shows the arteries live on a screen
• Carried out through a skin puncture into the blood vessel feeding the narrowed or diseased vessels.
• Most often, the skin puncture is in the groin, at the top of the leg, but may be in the upper arm if the groin vessel can't be used.
• A contrast agent is injected into the artery to make it visible on the X-ray.
• Cardiologists carry out stent insertions in the coronary (heart) arteries.
• Radiologists carry out angioplasty and stent insertion in all other arteries in the body.

Angioplasty and Stent Insertion Preparation

• May require fasting for 4 hours prior to the procedure.

Potential Complications

• Bleeding: May require treatment to stop it or repair an injury to the vessel wall (pseudoaneurysm).
• Pseudoaneurysm: A local lump that can develop days or weeks after the procedure.
• Blocking the treated artery: Can make symptoms worse in the short term.
• Allergic reaction to contrast medium: Most reactions are mild, but rarely can be severe.
• Kidney failure: More likely in patients with diabetes or chronic kidney dysfunction.
• Allergic reaction to sedation drugs or other medications.

Benefits

• Re-opens the artery to restore blood flow, which may:
  • Help with walking without pain
  • Allow a wound/ulcer on the leg or foot to heal
  • Reduce abnormally high blood pressure
  • Preserve kidney function
  • Stop abdominal pain due to reduced blood supply to the bowel
  • Prevent stroke

Balloon Angioplasty

• Restores the normal caliber of localized narrowing of arteries and veins, as in atherosclerosis or congenital narrowing.
• May be used for small malformations with low hemodynamics.

Embolization

• Injection of thrombosing or foreign material to block the downstream vascular tree and reduce blood flow.
• Can reduce the probability of hemorrhage, improve blood flow to the neighborhood, improve overall circulation and other symptoms.
• Requires careful targeting to limit embolization to the intended area.
• May directly puncture and inject sclerosing material to obliterate purely venous malformations and low-flow vascular lesions.

Embolic Material

• Solid particles: Small powder-like material with variable sizes, giving control over the size of blood vessel penetration.
• Liquid: Polymerizes rapidly into solid material, taking the shape of the blood vessel and occluding it.
• Coils: Sizeable metallic filaments driven into a vessel, acting as foreign material inducing thrombosis.
• Some embolic materials are permanent (e.g., coils, liquids) while others are temporary (e.g., gel foam, autologous blood clots).

Bleeding

• Embolization is the treatment of choice for uncontrolled/persistent hemorrhage anywhere in the body.
• Applications include Epistaxis, GI bleeding, hematuria, obstetrical or gynecological causes, bleeding neoplasms or hemorrhage due to trauma.

Pulmonary Embolism

• A potential complication to deep venous thrombosis, most commonly in the lower limbs.
• May occur with a variety of materials, including blood clots (most common), fat, and air.
• Fresh thrombus may dislodge and flow to the pulmonary arteries, blocking circulation and causing hypo-oxygenation.
• Risk of Pulmonary Embolism is lower if the patient with deep venous thrombosis is on anticoagulants.
• Anticoagulants may need to be stopped in some cases where the patient has bleeding elsewhere in the body, increasing the likelihood of PE.

IVC Filter

• A metallic filter shaped like an umbrella is applied into the patent IVC (like a stent).
• The filter's limbs act as strainers to lodge floating thrombi, sparing the pulmonary arteries.

Varicose Veins / Varicocele

• Varicose veins are dilated, tortuous veins, commonly associated with pain and skin alteration due to increased venous pressure in the lower limbs.
• Treatment aims to get rid of the diseased vein, traditionally done surgically.
• Varicocele is varicosity of veins around the testicles due to stagnation of flow in the unhealthy testicular veins, with subsequent increased pressure.
• The diseased vein can be ablated with chemical cautery, mechanical or thermal energy effect, leading to obliteration.
• Radiofrequency ablation (RFA) destroys venous mucosa, leading to fibrosis and obliteration.
• Varicocele treatment involves embolization of the testicular vein with liquid embolic material, leading to occlusion.
• This is done after catheterization of the testicular veins bilaterally.

Oncology

• IR has significantly benefited the field of Oncology.
• Diagnostic image-guided fine needle biopsies are commonly practiced.
• This saves time, cost, and stress associated with surgical exploration and core biopsies under general anesthesia.

Bursal Injection

• Involves injecting a corticosteroid and local anesthetic into the bursa to reduce inflammation.
• This should result in pain relief and swelling reduction.
• May be used to assess if the bursa is the cause of pain.
• A good response to the injection confirms that the source of pain is the bursa.
• If there is no improvement, the pain is unlikely to be arising from the bursa or adjacent structures.

Potential Complications

• Tissue atrophy: Thinning or scarring of the skin or subcutaneous fat, more likely with repeated injections at the same location.

Benefits

• Reduces inflammation in or around the bursa, resulting in pain relief and swelling reduction.
• Helps to determine if the bursa is the source of pain.

Carpal Tunnel Ultrasound and Injection

• Ultrasound imaging is used to guide injections into the carpal tunnel to treat carpal tunnel syndrome.
• Injection involves a corticosteroid and local anesthetic to reduce inflammation and relieve pain.

This quiz explores various interventional radiology procedures, including angioplasty and stent insertion. Learn about the techniques employed and the equipment used in these minimally invasive procedures. Discover how MRI availability affects their usage in medical practice.