Both the “fem” and “pop” of fem-pop bypass are abbreviations for arteries in the leg. The femoral artery is the major artery of the upper leg while the popliteal artery is the main artery in the lower leg. A fem-pop bypass, therefore, is a surgery that connects the femoral artery to the popliteal artery through a bypass graft. The graft, either made of plastic or another blood vessel, bypasses the diseased portion of the leg artery.
A fem-pop bypass surgery is performed to treat diseased arteries of the leg, a condition that leads to a symptom called claudication. Claudication is to the legs what angina is to the chest. Claudication is the squeezing, aching, tightness that is caused from lack of blood flow to the leg. Just as angina is worse with exertion, so is claudication in the leg. Patients with peripheral arterial disease will state that their legs ache when the walk. Unlike that pain of muscle exertion, the ache of claudication subsides soon after the person rests. This pain on exertion occurs because the feet and legs need more blood during exercise, which they cannot get it because the femoral or popliteal artery is blocked by disease. The pain resolves quickly at rest because the need for blood in the extremities decreases at rest—the pain subsides.
In patients with severe claudication and peripheral arterial disease, a fem-pop bypass can restore adequate blood flow to the lower leg and foot because the disease area is bypassed with a graft or other blood vessel. Most often, surgeons will attempt to find another blood vessel in the leg to use as a donor for the graft but, if there is not a suitable blood vessel, a synthetic graft with be used.
Often a synthetic blood vessel graft will be made of a plastic like polytetrafluoroethylene (PTFE) or Dacron. These materials are rigid enough to be sutured into place but flexible enough to allow body movement. While synthetic materials will close off over time—a little faster than natural blood vessels—in severe peripheral blood vessel disease it may be the only option. The synthetic materials are still effective. For example, five years after a fem-pop bypass using a natural blood vessel, three-quarters of patients will still enjoy an open graft. When an artificial fem-pop bypass graft is used, only one-half of patients will still have an open graft after five years.1
It is important to note that the mortality rate of fem-pop bypass surgery is one to three percent, which is quite high. Fortunately the increased use of angioplasty and arterial stenting has reduced the number of fem-pop bypass procedures that are performed. When the blockage is in a larger artery it may be possible to advance a stent from within the artery rather than bypass the lesion with a fem-pop bypass graft. For people with several different areas of diseased artery or even large single blockage, fem-pop bypass is preferred to angioplasty—an arterial stent would not be sufficient.
Fem-pop bypass surgery is reserved for patients with severe peripheral artery disease, those that are having significant claudication symptoms e.g. walking is too painful or not possible. Fem-pop bypass surgery is also indicated when there is a risk of losing the leg or foot due to poor blood flow.
(1) Archie JP, Jr. Femoropopliteal bypass with either adequate ipsilateral reversed saphenous vein or obligatory polytetrafluoroethylene. Ann Vasc Surg 1994;8:475-484.