Lower extremity PAD, often called peripheral vascular disease or PVD, is a condition that develops when the arteries in the legs and feet become narrowed, or blocked, by an accumulation of a fatty substance called plaque, which builds up on the inside walls of the arteries. This narrowing is also called stenosis. As the arteries narrow, blood supply to the muscles and tissues in the legs and feet decreases, causing pain, poor healing, and in severe cases tissue death or gangrene.
Lower extremity PAD is one manifestation of atherosclerosis: the hardening and narrowing of the arteries due to plaque build-up. Atherosclerosis is a systemic disease occurring throughout the body. It affects as many as 35 percent of Americans. People with lower extremity arterial disease often have other cardiovascular problems caused by atherosclerosis, such as carotid artery disease and heart disease.
Risk factors for PAD include:
- smoking – the number one risk factor for all cardiovascular diseases
- high blood pressure
- high cholesterol
- advanced age (over 50)
- obesity (being 30 percent over your ideal body weight)
- a personal or family history of atherosclerosis
- sedentary lifestyle
The symptoms of lower extremity arterial disease include:
- Claudication: cramping pains while walking, usually in the calf muscles but sometimes in the thighs or buttocks. Claudication is the most common symptom of this condition.
- Pain in the feet and, as the disease progresses, in the toes while at rest.
- Coolness, numbness, or weakness in the legs and feet.
- Poor healing of wounds in the legs and feet.
- Ulcers of the feet and legs, which develop when the blood supply to tissue is cut off, and which can become gangrenous if untreated.
- Black discoloration of the toes or skin.
To determine the severity of blood flow impairment to the leg, doctors compare the blood pressure in the ankle to that in an arm using a simple test called the ankle brachial index (ABI). Other noninvasive testing approaches include pulse volume recording (PVR) and vascular ultrasound.
Doctors may also use imaging tests such as arterial duplex ultrasound, computed tomographic angiography (CTA), and magnetic resonance angiography (MRA) to determine the location and the extent of arterial stenosis in the legs.
An angiogram is a diagnostic imaging test that allows doctors to view blood vessels throughout the body and diagnose blockages, enlargements, clots, and malformations. An angiogram to study the arteries is called an arteriogram; one to study the veins is called a venogram. Before the test, doctors inject a dye into the vessels to be imaged using a long, flexible, hollow tube called a catheter, which is usually introduced into the body through a needle puncture in the groin. The dye makes the blood vessels clearly visible on an X-ray image. Most vascular specialists here at NewYork-Presbyterian Hospital both diagnose and treat vascular problems during the same procedure, combining an angiogram with one of the minimally invasive procedures outlined below: balloon angioplasty, stenting, atherectomy, or other procedures.
Patients whose symptoms are mild to moderate can often manage their disease by making lifestyle changes such as quitting smoking, getting regular exercise – which can be a tremendous help in relieving symptoms ‐ and working with their doctors to take care of related conditions, such as diabetes, high blood pressure, and high cholesterol. Doctors may also prescribe blood-thinning drugs or other medications.
Doctors often use minimally invasive procedures such as balloon angioplasty, atherectomy, and stenting to relieve the narrowing in the blood vessels and improve blood supply to the extremities.
During angioplasty, a deflated balloon-tipped catheter is inserted through an artery in the groin and guided to the narrowed segment of the artery. When the catheter reaches the blockage, the balloon is inflated, compressing the plaque and widening the artery.
In some cases, doctors may place a stent, a small metal scaffolding, to bridge the site of the blockage during angioplasty. The stent is collapsed when it is placed on the tip of the catheter and inserted into the body. Once the catheter reaches the blockage, the stent is deployed. The stent is a permanent device, left in place to provide a reinforced channel through which blood can flow. Some stents (drug-eluting stents) are coated with medication that helps prevent the formation of scar tissue.
During atherectomy, doctors use a specially equipped catheter to remove plaque from an artery's lining. The atherectomy device is inserted into the body through a catheter in the groin and is advanced through the artery to the site of the blockage, where the device is activated. Atherectomy devices are equipped with a rotating blade, which shaves plaque off of the inside of the artery walls, or a burr, which grinds hardened plaque from the artery wall. It is then removed from the body through the catheter.
In some cases, surgical procedures are required – such as peripheral artery bypass surgery, which reroutes the blood flow around the blockage, or endarterectomy, which surgically removes the blockage.
At NewYork-Presbyterian Hospital, we are always researching new and advanced therapies to treat lower extremity arterial disease.