Peripheral Vascular Disease
Blockages can occur in any
artery in the body. One of the most common places for an obstruction
is in the artery feeding the leg. The picture to the left represents
an obstruction in the superficial femoral artery, which gives blood
supply to the knee, calf, and foot. The usual symptoms with this type
of blockage are pain and/or heaviness in the calf with walking. The
pain may also include the foot. As the obstruction to blood flow increases,
the symptoms occur with walking shorter distances. The pain usually
goes away with rest. In the most extreme cases, there may be pain in
the foot at all times, even at rest. There may be sores and ulcers on
the ankles, feet, or toes, or there may be outright gangrene of the
toes and foot. Symptoms are due to lack of adequate blood flow to the
lower leg and foot. 
This
type of problem can be corrected by performing a bypass around the blockage,
as depicted at right. The bypass allows blood to go through a tube graft
connected on one end to an artery upstream from the obstruction and
on the other end downstream from the obstruction.The tube graft is usually
made of a material called PTFE, otherwise known as Goretex, but other
materials can also be used, including the patient's own veins. Supplying
more blood flow to the leg and foot usually provides immediate relief
of the painful leg and foot with walking.