How Angioplasty Saves Legs from Gangrene — A Step-by-Step Explanation

The concept of treating gangrene with a needle puncture and a tiny balloon sounds remarkable — but it is now routine interventional radiology. Here is exactly how it works.

Why Opening the Artery is the Key

Vascular gangrene is tissue death caused by insufficient blood supply. The artery supplying the leg has become narrowed or blocked by atherosclerotic plaque — hardened deposits of cholesterol and calcium. The body cannot remove this plaque on its own. Angioplasty physically compresses the plaque and widens the channel, restoring blood flow.

The Procedure — Step by Step

1. Preparation: The patient lies on the procedure table. Local anaesthesia is injected at the access site — usually the groin artery (femoral artery) or occasionally directly at the foot artery for below-knee disease. No general anaesthesia is required.
2. Access: Using ultrasound guidance, a needle punctures the artery — about the size of a pen tip. A thin plastic sheath (introducer) is placed through the needle to provide a stable access point.
3. Angiogram: Contrast dye is injected and X-ray images are taken, creating a real-time map of the arteries — showing exactly where the blockages are, how long they are, and which arteries are involved.
4. Crossing the blockage: A very thin guidewire (0.018 to 0.035 inches) is navigated through the blocked segment under X-ray guidance. This is often the most technically demanding step — especially in complete occlusions. Dr. Rohit Agarwal uses specialised wires and techniques including subintimal angioplasty for long, complex blockages.
5. Balloon angioplasty: A catheter with a tiny balloon at its tip is advanced over the wire to the blockage. The balloon is inflated under high pressure (4–16 atmospheres) for 30–120 seconds, compressing the plaque and cracking it to widen the lumen.
6. Drug-coated balloon: For arteries where re-narrowing is a risk (particularly below-knee vessels), a drug-coated balloon coated with paclitaxel is used. The drug prevents the scar tissue response that causes the artery to narrow again.
7. Stenting (if needed): If the artery recoils or there is a significant dissection, a metallic stent is deployed to hold the artery open permanently. Drug-eluting stents are used in specific locations.
8. Completion angiogram: Final images confirm that blood flow has been restored all the way to the foot. Most patients feel their foot warming and pain reducing on the table.
9. Closure: The access sheath is removed and the puncture site is sealed with a closure device or manual pressure. No stitches. No dressing required beyond a small bandage.

What Happens to the Gangrene After?

With blood flow restored, the process of tissue death stops. Viable tissue at the margins of the gangrenous area begins to recover. Existing wounds and ulcers now receive oxygen and nutrients and begin to heal. Over the following weeks, the demarcated dead tissue may separate naturally. Wound care continues in parallel. In many cases, only the already-dead tissue needs to be removed — the surrounding foot is saved entirely.