Opening Up Treatment for Peripheral Artery Disease

Lessons from the heart may translate to better treatment for blocked arteries in the legs and elsewhere.

The heart isn't the only place in the body where the onslaught of high blood pressure, inflammation, and an overload of circulating fat stiffen and narrow arteries. It happens in the brain and the kidneys as well. Compromised arteries can even run through the legs and arms.

The condition of stiff, clogged arteries beyond the heart is called peripheral artery disease. The name makes it sound trivial. It's anything but. More than 10 million Americans have this disease. Some have no symptoms. But many have leg pain when they walk that makes it difficult, or even impossible, to cross a street or climb stairs. Each year, thousands lose a foot or leg because of poor circulation. And everyone with it faces substantially higher than average chances of having a heart attack or stroke, or dying early.

Peripheral and Central Problems

Peripheral artery disease is a pain. Literally. The classic symptom is aching, burning, or heaviness in the legs or buttocks that comes on with walking or stair climbing and stops when resting. (This is also known as intermittent claudication.) It occurs because one or more narrowed arteries thwart the delivery of enough oxygen-rich blood to meet the needs of the leg muscles. It's the same imbalance between supply and demand that causes chest pain (angina) with exercise or activity.

Only about one in three people with peripheral artery disease has this classic symptom. Other symptoms include pain in the hips or lower back; numbness, tingling, or coldness in the lower legs or feet; or sores or ulcers on the legs or feet that won't heal. In some men, the first sign is impotence, caused by poor blood flow to the penis.

In addition to causing pain and interfering with daily activities, peripheral artery disease can also interfere with one's lifespan. It increases sixfold the chances of having a heart attack or stroke or dying from heart disease.

Exercise and Medicine First

The most effective treatment for peripheral artery disease is exercise. Alternating between walking and resting during a 30-minute period several days a week trains leg muscles to work with less oxygen. Exercise also improves blood sugar, cholesterol levels, blood pressure, and weight — changes that may lessen leg pain and will definitely improve all-around cardiovascular health.

Drug therapy may also help. Pletal (cilostazol) and Trental (pentoxifylline) can ease leg pain. Aspirin and Plavix (clopidogrel) are important for preventing heart attacks, strokes, and amputations. Taking a cholesterol-lowering statin may also improve leg function.

Exercise plus drug therapy and other lifestyle changes — stopping smoking is essential, and weight loss can help, too — works for most people with peripheral artery disease.

More drastic measures are needed if these aren't enough to let you work or do your usual activities. Leg pain at rest or a blockage that threatens to completely cut off blood flow to the leg or foot also call for more aggressive therapy.

Bypass Blocked Arteries

Surgery was once the gold standard by which other procedures were measured. The location of the blockage determines the operation used. There are three main types: aortobifemoral bypass, for blockage in the large arteries of the abdomen or pelvis (the aorta or iliac arteries); femoropopliteal bypass, for arteries in the thigh or just below the knee; and tibioperoneal bypass, for diseased arteries in the lower leg or foot.

All are fairly major procedures, requiring anesthesia, a several-day hospital stay, and an extended recovery. They stress an already fragile heart — where there are diseased leg arteries there are usually diseased coronary arteries. They also carry the complications connected with any major surgery.

Surgery can save a threatened limb or ease pain, but it doesn't check atherosclerosis. It may ease leg pain, but doesn't necessarily eradicate it. In addition, the bypass itself can narrow, or even fail.

Surgery is usually reserved for people with disabling or limb-threatening peripheral artery disease. A kinder, gentler alternative could offer relief for more people.

Opening Blocked Arteries

Opening arteries from the inside, the Roto-Rooter approach known as angioplasty, is one alternative. It uses a tiny balloon on the end of a flexible wire (catheter) to flatten fat-filled plaque against the artery wall. The wire and balloon are deftly maneuvered into place from a small nick near the top of the leg.

This opens the artery immediately, without the complications and recovery of surgery. But the blood vessel doesn't always stay open. The sudden smashing of plaque sometimes irritates the inner lining of the artery wall so much that scar tissue begins to form. It can grow large enough to close off the artery again, a process known as restenosis (ree-sten-OH-sis).

To help keep the artery open, a mesh tube, known as a stent, is usually used to prop open a balloon-widened artery. There are two types of stents, bare metal stents and drug-coated stents. Bare metal stents promote more restenosis than the drug-coated stents. However, the drug-coated stents are more prone to late blood clots inside the stents; so people who get a drug-coated stent need to take two anti-clotting medications, aspirin and clopidogrel (Plavix) for at least one year.

The choice of stent depends upon the size of the artery that needs to be opened and the patient's risk for bleeding complications.

Compared with surgery, angioplasty puts less strain on the heart, causes fewer complications, and allows for quicker recovery. It also leaves the door open for an operation if surgery is needed later. So if angioplasty turns out to be as effective as surgery, it would be a good alternative.

Angioplasty for peripheral artery disease   Angioplasty for peripheral artery disease   One way to treat peripheral artery disease is by passing a deflated balloon to the blocked area, then inflating it to open the artery. Depending on the location of the narrowing or blockage, a tiny metallic stent is left in place to keep the artery open.

On the Horizon

Common conditions that don't have a front-runner therapy attract their share of novel treatments. That's certainly the case for peripheral artery disease.

On the angioplasty front, several approaches are under investigation. One is subintimal angioplasty. This involves making a channel between the inner and outer walls of the artery, rather than through the narrowed channel down the middle. Another uses frigid nitrous oxide ("laughing gas") instead of salt water to expand the angioplasty balloon. The gas freezes the plaque and the inner lining of the artery, which appears to limit restenosis. A third uses a stent made from magnesium that the body gradually absorbs once it has done its job.

For arteries blocked by a clot (thrombus), a variety of devices that use tiny mashers, suckers, or shavers are being tested as replacements for balloon angioplasty. It may even be possible to open narrowed or blocked leg arteries by activating plaque-busting drugs with light from a laser fiber drawn through an artery.

Gene therapy and stem cells are also in the running, but right now they are long shots.

Which One is Right for You?

Surgery and angioplasty relieve the symptoms of peripheral artery disease by restoring blood flow through a blocked or narrowed artery. But they don't do anything to slow or fight the disease that caused the problem and that almost invariably is affecting other arteries in the legs, arms, heart, and elsewhere.

For the best results, surgery or angioplasty should be combined with exercise, drug therapy, and healthful lifestyle changes. This trio can prevent symptoms from getting worse, and can even make them better by slowing or stopping atherosclerosis.

Angioplasty and stenting might be right for you if the trouble-causing artery is narrowed, not blocked; if the narrowing is short, not long; if it is higher in the leg, rather than lower; if the artery wall is clear, rather than full of calcium; if you don't have diabetes and do have good kidney function. Otherwise, surgery may be the better route.