Peripheral Arterial Disease (Lower Extremity Arterial Disease)

What is Peripheral Artery Disease (PAD)?

Peripheral arterial disease (PAD), sometimes called peripheral vascular disease or lower extremity arterial disease, is a narrowing of the peripheral arteries that carry blood away from the heart to the rest of the body. The arteries can 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. Without adequate blood flow, your vital organs, arms, legs, and feet can suffer lasting damage, and you may be at risk for life-threatening heart attack and stroke.

Critical limb ischemia, the most severe form of PAD, is caused by narrowing or blockages in blood vessels supplying blood to the legs/feet. This condition may cause ulceration of the skin (such as sores on the lower legs) and even progress to a point where amputation may be required.

Other blood vessel problems linked to PAD include deep vein thrombosis (DVT), varicose veins, and chronic venous insufficiency.

PAD and atherosclerosis

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. People with PAD often have other cardiovascular problems caused by atherosclerosis, such as carotid artery disease and heart disease.

Signs & Symptoms

Many people with PAD have no symptoms. The most common symptoms of PAD include:

• Claudication - pain or cramping in the calves or thighs while walking
• 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
• Black discoloration of the toes or skin (gangrene)
• Weak pulses in the legs and the feet
• Hair loss on the legs
• Thickened, discolored toenails
• Inability to have an erection (impotence)

Risk Factors

The risk factors for PAD include:

• Smoking is the number one risk factor for all cardiovascular diseases
• High blood pressure
• Diabetes
• High cholesterol
• Advanced age (over 50)
• No longer having menstrual periods (postmenopausal)
• Obesity (being 30 percent over your ideal body weight)
• A personal or family history of atherosclerosis or heart disease
• Sedentary lifestyle

The PAD-CAD connection

If you have coronary artery disease (CAD), or coronary heart disease, you are at increased risk of peripheral artery disease, or PAD. Similarly, if you have PAD, you are at increased risk for CAD as well. CAD can increase your risk for heart attack and stroke.

Diagnosis

Our vascular specialists begin with an assessment and consultation, which will include reviewing your medical history and obtaining any imaging and blood tests necessary for diagnosis.

Noninvasive vascular imaging

To accurately diagnose abnormalities in the vascular system, our specialists use the most advanced noninvasive tests available, including:

• Ankle-brachial index (ABI) - An ABI is a comparison of the blood pressure in the ankle with the blood pressure in the arm. It helps to diagnose PAD and checks for changes in blood flow over time.
• Arterial and venous Doppler ultrasound flow studies - This uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Doppler technique is used to measure and assess the flow of blood. Faintness or absence of sound may mean an obstruction in the blood flow.
• CT Angiography (CTA) - This test uses an injection of contrast material into your blood vessels and CT scanning to help diagnose and evaluate blood vessel disease or related conditions, such as aneurysms or blockages
• Magnetic resonance angiography (MRA) - This procedure uses large magnets, radio frequencies, and a computer to produce detailed images. An MRA is typically only done if plans are being made to restore normal blood flow through a procedure or surgery.
• Photoplethysmography (PPG) - This exam is like the ankle brachial index except that it uses a very tiny blood pressure cuff around the toe and a PPG sensor (infrared light to evaluate blood flow near the surface of the skin) to record waveforms and blood pressure measurements. These measurements are then compared to the systolic blood pressure in the arm.
• Pulse volume recording (PVR) waveform analysis - This test checks for changes in the amount of blood in the legs
• Segmental blood pressure measurements - Blood pressure measurements are taken at various points along the arms or legs. The level and severity of disease can be identified through segmental blood pressures.
• Treadmill exercise tests - Some of the above tests can be done before and after exercise. This is especially helpful for evaluating patients with symptoms during exercise.

Treatment

The main goals for the treatment of PAD are to control the symptoms and to prevent future complications. Treatments for PAD range from lifestyle modification to minimally invasive therapies to surgery. Our vascular specialists will provide you with an individualized plan of care. We will work with your primary physician to provide comprehensive vascular care and communicate regularly regarding your long-term vascular health.

Lifestyle modification

Patients whose symptoms are mild to moderate can often manage their disease by making lifestyle changes such as quitting smoking, getting regular exercise, improving diet, and working with their doctors to take care of related conditions, such as diabetes, high blood pressure, and high cholesterol.

Medical therapy

Medical therapy may be used to target leg or arm discomfort that occurs with exertion and as a result of clogged arteries. Doctors may also prescribe medications to improve blood flow, such as antiplatelet agents (blood thinners) and medications that relax the blood vessel walls. Medications are also used to treat underlying conditions such as diabetes, hypertension, and high cholesterol.

Minimally invasive approaches

Vascular specialists often use minimally invasive procedures such as balloon angioplasty, lithotripsy, atherectomy, and stenting to relieve the narrowing in the blood vessels and improve blood supply to the extremities.

Balloon angioplasty

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. Some balloons are coated with a medication that helps prevent the formation of scar tissue.

Intravascular lithotripsy (IVL)

Intravascular lithotripsy (IVL) is used to treat severe calcium prior to the insertion of a stent in the artery. The IVL procedure uses a catheter that is threaded into the narrowing from the wrist or leg artery and delivers sonic pressure waves to create a series of microfractures to break up calcium in the artery.

Atherectomy

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.

Stenting

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 or DES) are coated with a medication that helps prevent the formation of scar tissue.

Surgery

In some cases, surgical procedures are required – such as peripheral artery bypass surgery, which reroutes the blood flow around the blockage, or endarterectomy, to remove the blockage.

Prevention

PAD is preventable with strategies that stop the narrowing of the arteries in people who are at risk. Our vascular specialists can determine your risk by gathering information such as your age, weight, medical history, medications, and lifestyle factors. You can take steps to prevent PAD, or prevent it from getting worse with the following steps:

• Stop smoking, including staying away from secondhand smoke
• Healthy eating including reduced fat, cholesterol, and sugar, and increased fruits, vegetables, whole grains, and healthy protein (lean meats, fish, and soy)
• Treatment of high cholesterol with diet, exercise, and medicine
• Losing weight if overweight
• Limiting the amount of alcohol you drink
• Taking medicine to reduce your risk for blood clots
• Regular exercise
• Control of blood sugar levels
• Control of blood pressure