March 30, 2012
Dear Mayo Clinic:
I am a 52-year-old man who was very active until suffering a blockage of the artery behind my right knee. Are there any treatments for this?
There are several ways to treat the type of blocked artery you describe. The specific treatment you need depends on the severity of your symptoms and the extent of the blockage.
Your condition, called peripheral artery disease, is a common problem in which narrowed arteries reduce the amount of blood that reaches the limbs. The most frequent cause is a buildup of fat and calcium deposits on artery walls. Over time this buildup, or plaque, can limit blood flow through the artery and lead to serious problems including tissue death and gangrene, which can require amputation of the affected limb.
Plaque, when it begins to form, doesn't cause symptoms. But it can be detected during a physical exam when blood pressure in an ankle or leg is compared to blood pressure in an arm. Normally blood pressure is higher in the legs than in the arms. As a blockage develops, though, blood pressure in the leg falls.
Factors that increase risk for plaque buildup include cigarette smoking, diabetes, kidney failure, high blood pressure and high cholesterol.
If these factors are not controlled, plaque continues to build and symptoms begin to appear. The most common symptom, called intermittent claudication, is leg pain or cramp with walking. Depending on how advanced the disease is, the pain may be mild or severe. As the disease progresses, the distance you can walk without pain gets shorter.
If nothing is done to treat the risk factors, peripheral artery disease can progress to its most serious stage, in which blood flow to the limb is dramatically decreased. A telltale symptom of this stage is leg pain when resting, particularly at night when the leg is raised into bed. Often, patients must get out of bed or dangle the foot outside the bed to relieve symptoms.
When peripheral artery disease is diagnosed in the early stages of the disease, lifestyle changes are often enough to treat it. Quitting smoking, eating a healthier diet and controlling high blood pressure, high cholesterol or diabetes, along with daily exercise, can all help. These steps typically slow or stop progression of the disease because they allow the body to develop other channels that blood can flow bypass the blockage. Exercise can help condition muscles to get oxygen from blood more efficiently, so the muscles can work better despite reduced blood flow.
If lifestyle changes are not enough to slow the disease's progress, or if severely limited blood flow threatens the viability of the leg, additional treatment may be necessary.
One treatment possibility is bypass surgery. A blood vessel from another part of the body or an artificial blood vessel is placed around the blockage in the leg, so blood can flow around the affected artery.
A less invasive approach involves endovascular treatment, which includes options such as angioplasty, stents and plaque removal. In angioplasty, a small hollow tube, called a catheter, is threaded through a blood vessel to the blocked artery. A small balloon on the tip of the catheter is inflated to expand the artery, flatten the blockage and stretch the artery open to increase blood flow. A mesh metal framework, called a stent, may be placed in the artery to keep it open. Some catheters can also be used to remove plaque. The plaque buildup can be physically removed from the artery, either by scraping it out with a blade or drill or using a laser to destroy it.
For a person in your situation, a conservative approach to treatment is usually an appropriate first step. Medical intervention typically is not necessary unless peripheral artery disease has advanced to the point that the health of the limb is threatened.
— Gustavo Oderich, M.D., Vascular Surgery, Mayo Clinic, Rochester, Minn.