Dangerously Undiagnosed: Peripheral Arterial Disease

Are you familiar with PAD? If not, you’re not alone. Seventy-five percent of US adults have never even heard of this common condition, and yet it affects 12 million Americans – more than all types of cancer combined. Ten to twenty percent of people 65 and older have PAD. Because the disease is under-diagnosed, an estimated 30 % of people with PAD don’t even know they have it.  Unfortunately, when it comes to PAD, what you don’t know really can hurt you.

Peripheral arterial disease (PAD) is narrowing (stenosis) in the arteries of the legs caused by atherosclerosis, the plaque build up associated with heart disease and stroke. About a third of people with PAD develop such severe impairment in blood flow that they are likely to lose their leg if blood flow is not restored. We call this limb-threatening ischemia, and it can be associated with leg wounds that don’t heal, gangrene (dead tissue) or unremitting pain in the foot or lower leg.

When walking starts to hurt

The earliest sign of PAD is claudication – leg pain with walking that improves immediately when you rest. Patients typically describe claudication as a deep muscular ache or weakness in the back of the calf or, less commonly, the thigh. The pain arises only after walking a certain distance, and comes on more readily if you are walking at a fast pace, or uphill.  Claudication dissipates once you have been standing still for a few minutes.  Most people do not develop this type of pain with other forms of exercise, such as riding a bike, swimming, or working out on a stair-step machine. Claudication should not be confused with sciatica, a stinging or burning pain that shoots down the back of the leg and is caused by a pinched nerve in the back. Unlike claudication, sciatica pain can arise from standing or sitting too long and usually takes a while to dissipate. Arthritis pain can also be mistaken for claudication, but arthritis involves the joints rather than the muscles, and arthritis pain is typically at its worst when you first start an exercise and diminishes as you keep going.

Testing for PAD involves checking pulses in the legs and performing an ankle-brachial index (ABI). The ABI is a ratio of the blood pressure in the leg to the blood pressure in the arm. It is normal when the pressures are equal. If the blood pressure in the leg is lower than in the arm, the ABI is abnormal. An ultrasound or CT can be performed to locate a specific region of stenosis or occlusion in the leg.

Getting a leg up on PAD

Treating PAD begins with controlling risk factors for atherosclerosis, such as high blood pressure, elevated cholesterol, and diabetes, or pre-diabetes. It is essential to stop smoking immediately. There are two approaches to treating a dangerous arterial narrowing or blockage associated with PAD: bypass surgery and angioplasty.

Bypass surgery

A bypass is a surgery used to treat blockages in arteries or arterial aneurysms. A tube (graft) is tunneled through the leg and sewn into the artery above the blockage and the artery below the blockage, to create the bypass, a detour around the occluded segment. Bypass surgery can usually be performed through 2 or 3 small incisions in the leg, with the patient under spinal or light general anesthesia.   Generally, patients stay in the hospital a day or two after surgery.

Angioplasty

Angioplasty is a minimally invasive way of treating blockages in arteries. A small tube (catheter) is inserted into the artery through a needle stick in the groin. Contrast dye is injected into the artery and continuous X-ray monitoring (fluoroscopy) is used to reveal areas of stenosis. A wire and a balloon catheter are then threaded through the artery, past the region of blockage, to dilate the artery from the inside. This literally “cracks” the plaque, expanding the vessel to make more room for blood to flow through the artery. Angioplasty can be performed in the operating room or fluoroscopy suite, under a local anesthetic with sedation. Patients can generally go home the same day.

Both bypass and angioplasty patients may be prescribed aspirin or a blood thinning medication after their procedure.  Bypass is the more invasive procedure, but is generally associated with better long-term outcomes than angioplasty. Angioplasty is minimally invasive and healing time after the procedure is generally very brief. However, angioplasty may not last as long as bypass surgery. Over time, re-narrowing of the artery (restenosis) is not uncommon.

The best way of reducing your risk of developing complications of PAD is to become informed.  If you have risk factors, consider a screening (see sidebar). If you think you may be experiencing claudication, don’t wait:  make an appointment to see your doctor today.