FEBRUARY 4, 2010
by Michael Jaff, MD
Peripheral Arterial Disease (PAD), a condition commonly correlated with diabetes, also known as a “silent killer,” affects at least one in every three diabetics over the age of 50 and approximately eight million Americans in total over the age of 40. Although PAD is prolific among diabetic and senior populations, current data show that public and physician knowledge of the disease is startlingly low, with only 25 percent of the affected population seeking treatment.
Diabetics are at the greatest risk for developing severe PAD and experiencing complications from the disease, as they have difficulty properly processing the sugar they ingest. As a result, plaque (fatty deposits) accumulates in the arteries, triggering a change in internal blood vessel size and elasticity, and subsequent circulation problems.
Plaque buildup causes an overall narrowing and hardening of the arteries and can eventually decrease the blood flow to the lower extremities. When blood flow to the legs becomes limited or restricted, the propensity for developing infections, chronic foot ulcers, gangrene and leg lesions dramatically increases. Not only that, but these foot wounds have difficulty healing, and in severe cases, the affected limb is so damaged that amputation is required if other available treatments fail. Fortunately, new medical devices and drugs are being developed, and in many cases amputation can be avoided or limited. Problems with the feet are one of the most common causes of diabetes-related hospitalizations. In fact, diabetics are up to fifteen times more likely to have to endure lower-limb amputation than those without diabetes.
Although a common indicator of PAD is extreme leg or buttock pain caused by walking or exercising, as many as 40 percent of people with PAD never complain of this symptom – and those who do commonly mistake the discomfort for aging pains and fail to seek treatment, allowing the condition to worsen. PAD is highly treatable in its early stages, but as the disease remains undiagnosed, the likelihood of facing complications greatly increases, as does the probability of suffering from heart attack or stroke.
Physicians can quickly and easily test for peripheral arterial disease, which can allow patients to undergo treatment for the condition and effectively arrest the progression of the disease. The most common test is the ankle-brachial index (ABI), a non-invasive process that compares blood pressure in the ankles with the blood pressure in the arms. An ABI can help determine if someone has PAD, but it cannot identify the location and degree of the obstruction in the artery. A Doppler test, which is non-invasive, that can check a specific artery for blockage is also available. The test uses ultrasound waves to measure blood flow in arteries within the lower extremities.
Once a clogged artery is identified, patients can consider several treatment options with their physician. Angioplasty is a non-surgical procedure that is used to widen arteries with constricted or blocked blood flow. During the procedure, a catheter with a balloon on its tip is inserted into the narrowed artery and inflated. Once the artery widens, the balloon is deflated and the catheter is withdrawn, often restoring blood flow.
Another option in certain arteries such as the iliac is a stenting procedure where a stent (a tubular wire-mesh tube) is inserted into the artery, where it is expanded to act as a “scaffold” to hold the artery open and allow blood flow to resume. The procedure is minimally invasive, as the stent is guided into the restricted artery with a catheter inserted through a small opening in the artery. Drug-eluting stents, which are coated with medicine that is slowly released into the artery, were created to prevent the plaque from growing around the stent due to inflammation and forming scar tissue, a process called restenosis. These devices have shown clinical effectiveness in treating coronary artery disease.
In situations where large sections of an artery are narrowed, arterial bypass is a surgical option. During leg bypass surgery, a vein from another part of the body or a fabricated blood vessel is sewn above and below the clogged area of the artery to detour blood flow around the blockage. Bypass surgery is a largely successful treatment option, but can be risky for patients who suffer from other disorders such as diabetes or high blood pressure.
People who have experienced any of the aforementioned symptoms or are at increased risk for PAD, especially those with diabetes, should speak to their healthcare professional immediately to schedule testing. Identification and diagnosis of peripheral arterial disease is critical, as early treatment can ultimately save a life.
Michael Jaff is medical director of the vascular diagnostic laboratory at Massachusetts General Hospital in Boston.