When an artery in the leg is blocked over a long segment, blood can be routed around it. A new channel is joined above and below the blockage, and flow is restored to the foot.
Peripheral arterial bypass creates a detour around a blocked leg artery using either the patient's own vein or a synthetic tube. It is done for rest pain, ulcers or gangrene that will not heal because there is not enough blood reaching the foot. Vein grafts last longer than synthetic ones below the knee. It is major surgery, and for many patients an angioplasty is tried first.
Arteries narrow with age, smoking and diabetes. While the narrowing is mild, the leg hurts only on walking and settles with rest. As it progresses the foot begins to hurt at night, ulcers appear and do not heal, and toes can become gangrenous. That stage is called critical limb ischaemia, and without restored blood flow most of those limbs are eventually lost.
There are two ways to restore flow. A balloon and stent passed from inside the artery can open a short narrowing, and is less invasive, so it is usually tried first. Where a blockage is long, heavily calcified or has already failed angioplasty, a bypass is the more durable answer.
The graft is joined onto healthy artery above the blockage and again onto healthy artery below it, and the blocked segment is simply left alone. The material matters. The patient's own great saphenous vein performs considerably better than a synthetic tube when the join below the knee is small, and it resists infection far better. Where no usable vein exists, a synthetic graft is used.
Bypass is major surgery in patients who often have heart and kidney disease too, so the decision balances the limb against the risk of the operation.
Imaging maps the whole arterial tree and identifies a healthy target artery beyond the blockage.
Where a vein graft is planned, the great saphenous vein is taken from the same or the other leg and checked for size and quality.
The artery is exposed above and below the blockage through separate incisions.
The graft is sewn onto healthy artery above the blockage with fine sutures.
The graft is passed under the tissues along the natural line of the artery to reach the lower site.
The lower join is made, flow is released, and the foot is checked for pulses and Doppler signal before closing.
Circulation to the foot is checked repeatedly. Pain relief, fluids and often a period in a high dependency bed. Swelling of the leg is expected.
Walking restarts with physiotherapy. Wounds in the groin, thigh and calf are monitored; these are the commonest site of trouble. Discharge when walking safely.
Wounds heal and leg swelling settles. Ulcers should be visibly improving now that blood supply has returned. Graft surveillance scanning begins.
Walking distance improves. Regular surveillance scans continue, and medication for cholesterol and platelets continues indefinitely.
A working bypass relieves rest pain quickly and usually allows ulcers to heal, which is the main purpose. Grafts do not last forever. Vein grafts stay open better than synthetic ones, particularly below the knee, and all grafts narrow at the joins over time. Surveillance scans exist to catch that narrowing before the graft blocks, because a narrowing can be corrected and a blocked graft often cannot. Walking distance improves but rarely returns to normal, since the underlying disease affects the whole arterial tree. Stopping smoking makes more difference to graft survival than almost anything the surgeon does.
These patients frequently have disease in the heart and kidneys as well, and the risks reflect that rather than the leg alone.
Graft survival depends more on what happens after the operation than during it.
It routes blood around one blockage. The underlying disease continues in the rest of the arteries, which is why medication, stopping smoking and surveillance all continue afterwards.
Above the knee the difference is small. Below the knee, vein grafts stay open considerably better and resist infection far better. If you have a usable vein, it is used.
Antiplatelet and cholesterol medication protect the graft and reduce the risk of heart attack and stroke. Stopping them is one of the commonest reasons grafts fail.
Sometimes flow is restored successfully but too much tissue has already died. A well planned amputation with a healed stump and a good prosthesis can give better function than a salvaged but painful foot.
Restoring blood supply and reconstructing the tissue that has already been lost are usually needed in the same patient. Having both available avoids the common situation where flow is restored but nobody will close the wound.
Bypass for critical limb ischaemia is commonly covered by health insurance and by government schemes including PM JAY. Cost depends on graft material, the length of the bypass, and whether intensive care and further wound surgery are needed. A written estimate follows angiography.
The things people want to know before agreeing to a long operation.
Ask your question →Angioplasty is less invasive and is usually tried first. It works well for short narrowings. For a long, heavily calcified blockage, or after an angioplasty has already failed, a bypass gives a much more durable result.
Vein grafts commonly stay open for years, synthetic ones less reliably, particularly below the knee. Longevity depends heavily on not smoking, taking your medication, and attending surveillance scans that catch narrowing early.
It usually improves considerably, but rarely returns to normal, because the disease affects arteries throughout the leg and body. The main aim of a bypass at this stage is to relieve rest pain and heal tissue, not to restore athletic function.
Swelling after restoring blood flow to a limb that has been starved is expected and usually settles over several weeks. Elevation helps. Swelling with increasing redness and pain should be reported, as it may indicate infection.
Tissue that has already died cannot be brought back. What a bypass does is provide enough blood supply for a minor amputation to heal, instead of needing a much higher one. Many patients keep a functional foot after losing one or two toes.
Seeing patients from across the city and beyond: read about the practice on the plastic surgeon in Surat page, or check what a written estimate covers on the costs and insurance page.
