Diagnosing Lower Extremity Arterial Disease

Lower extremity arterial disease—also known as peripheral artery disease, lower extremity—occurs when plaque forms in a leg artery, blocking blood flow. Plaque is composed of fat, cholesterol, calcium, and other substances in the blood. When plaque accumulates, it fully or partially blocks and narrows the artery, restricting blood flow to tissues in the leg and other parts of the body. This is sometimes called hardening of the arteries, or atherosclerosis. Poor blood flow may cause leg pain and increase the risk of developing open, infected sores on the skin. Without treatment, lower extremity arterial disease can cause leg tissues to die, sometimes requiring amputation. 

NYU Langone doctors diagnose and treat lower extremity arterial disease and prevent the condition from progressing. 

Signs and Symptoms

Lower extremity arterial disease usually affects just one leg. The most common and telling symptom of lower extremity arterial disease is leg pain after walking a short distance—the length of distance is different for every person, but is generally not far—known as intermittent claudication. 

The pain results from inadequate blood flow and oxygen to a leg muscle during physical activity. The pain tends to occur in the same area of the leg, such as the calf, whenever you walk, and stops after you rest for a few minutes. When you start walking again, the pain tends to return at about the same distance walked. Call your doctor if you notice this type of pain in your leg. 

Signs of lower extremity arterial disease include open sores on the legs or feet. They sometimes develop from a minor injury or scratch. Poor circulation in the leg can lead to dry skin that cracks. Because small cuts and cracked skin do not receive adequate blood flow to heal properly, bacteria can enter them, causing an infection.

If a sore becomes infected and is not treated, the tissue may die. This condition, called gangrene, occurs when a blocked artery prevents leg tissue from receiving adequate blood and oxygen. A leg with severe gangrene may need to be amputated if surgical treatment and medication do not restore blood flow. Signs of gangrene include skin discoloration; a foul odor; and pus, a fluid that forms at the site of an infection.

Early diagnosis of lower extremity arterial disease can help prevent serious complications; immediate treatment can improve your ability to walk and even save a limb. The vascular surgeons at NYU Langone have extensive experience in diagnosing and managing lower extremity arterial disease. They have been able to save the limbs of 70 to 80 percent of people who were scheduled for leg amputation at other hospitals. 

Risk Factors

Lower extremity arterial disease is often attributed to smoking, obesity, and poor nutrition. People with unhealthy cholesterol levels—due to hereditary factors or a high-fat diet—can develop blocked arteries. A sedentary lifestyle also increases risk, because blood flow can become sluggish in people who spend too much time standing or sitting. Regular exercise has been shown to improve blood flow and arterial health. 

Hypertension, also called high blood pressure, is another risk factor. High blood pressure damages arterial walls, making them more susceptible to blockages and narrowing. 

People with diabetes are at increased risk of developing lower extremity arterial disease because they are prone to developing blood clots in the arteries. They must achieve healthy blood pressure, blood glucose (sugar), and cholesterol levels to reduce their risk of developing an arterial blockage, especially in the lower legs. 

Smoking is a known risk factor for lower extremity arterial disease. In fact, in some people, smoking cessation alone may improve symptoms. 

Diagnostic Tests 

After your doctor examines you and takes your medical history, he or she may order one of the following tests to look for signs of an arterial blockage in the leg.

Arterial Doppler Ultrasound

A Doppler ultrasound uses sound waves to produce images that highlight blood flow in the leg arteries. This test detects and evaluates any blockages caused by plaque buildup.

During the ultrasound, the doctor places a handheld instrument called a transducer on your skin, transmitting sound waves that produce images of the leg’s blood vessels on a monitor. The procedure can take 30 to 60 minutes and does not cause any pain. Afterward, you can typically return to your regular activities. 

Blood Pressure Readings

Your doctor may measure blood pressure in the thigh, calf, and foot. Low blood pressure may be a sign of an artery blockage and inadequate blood flow. 

CT Scans

In a CT scan, X-ray technology is used to take multiple views of structures inside the body. At NYU Langone, our doctors use the least amount of radiation possible. Before the scan, you may be given an intravenous (IV) dose of a contrast material. This liquid travels through the blood vessels and highlights any blockages in leg arteries. This painless test typically takes 10 to 15 minutes to complete. 

Angiogram 

In an angiogram, X-rays are used to determine whether plaque has blocked the blood vessels. During this test, which requires local anesthesia, a doctor makes a small incision in the skin near the groin, inserts a thin tube called a catheter, and guides it into an artery. The doctor moves the catheter to the area in the leg to be examined and injects a dye that highlights on a series of X-rays any narrow, enlarged, or blocked blood vessels.

The procedure can last less than an hour or up to several hours, depending on what the doctor finds. You may feel some discomfort, including a feeling of pressure when the catheter is inserted and a sensation of warmth when the dye is injected. 

Afterward, your doctor may advise drinking extra fluids to flush the contrast material from your system. He or she may also recommend avoiding certain activities, such as heavy lifting and strenuous exercise, to prevent bleeding where the catheter was inserted. Your doctor determines whether you need to remain in the hospital, though many people go home the day of the procedure.