By JOANNE PALLOTTA, Tufts Medical Center Correspondent
Here is a number you can’t ignore: 8.5 million. If it were a lottery jackpot, you’d play. But, what if that number had to do with your health?
According to the Centers for Disease Control and Prevention, 8.5 million people in the United States have Peripheral Arterial Disease (PAD), painful muscle cramping and numbness in the lower legs or the feet that can often keep you awake at night. Ignoring the symptoms could cost you more than a good night’s sleep.
“Peripheral Artery Disease is as common as heart disease, which we hear about all of the time,” says Mark Iafrati, MD, Chief of Vascular Surgery and the Vascular Medicine Divisionin the CardioVascular Center at Tufts Medical Center. “Currently, there are about 200,000 major limb amputations that occur in the U.S. every year. The vast majority of those result from some combination of diabetes and PAD.”
Paying Attention to PAD
Peripheral Arterial Disease is the narrowing of arteries to the legs, stomach, arms and head. This most commonly affects the lower extremities because of a build-up of plaque.
“This is a ‘plumbing’ problem,” states Dr. Iafrati. “The blood needs to get from your heart to the muscles and skin in your legs.” If the so-called “pipes” are blocked, the blood doesn’t get there, leading to leg pain, unhealed ulcers, or even loss of limbs.
The prevalence of PAD increases over the age of 60. Risk factors include smoking, diabetes, high blood pressure, high cholesterol or even genetics.
Dr. Iafrati says that people who have PAD are more likely to also suffer from heart disease. The same type of fatty deposits that build up in and around the heart arteries can do the same in other arteries, reducing the blood’s ability to flow normally.
He emphasizes that taking steps toward a healthier lifestyle in your early years may actually prevent PAD.
Symptoms of PAD
The earliest effects of PAD on the artery walls may be seen in people as young as teenagers. However the blockages tend to develop slowly, over decades, as your body tries to correct this process of “atherosclerosis” with efforts to remodel the narrowed vessels or open collateral routes around the blockages. Most people can tolerate up to a 50 percent blockage of a leg artery before noticing any symptoms.
Once the blockages of PAD exceed a critical threshold, the lack of blood flow can start to cause noticeable problems. The earliest symptom of PAD is usually claudication or difficulty walking distances because of pain in the calves, thighs, or buttocks due to poor circulation. This problem tends to be reproducible and consistent and can greatly diminish people’s walking ability and quality of life.
More advanced PAD can cause pain when you are not on your feet. Rest pain is mainly in a person’s feet and can be excruciating especially when a person is sleeping or resting horizontally.
“You’re losing the benefit of gravity,” says Dr. Iafrati. “If you’re not doing something about it, you’re likely to end up in a situation where you’re losing tissue, toes, or feet.”
The most serious manifestation of PAD is loss of tissue – gangrene or ulcers that don’t heal. Those patients are at high risk of amputation, if not treated early.
Visually, Dr. Iafrati says you might notice a lack of hair on toes or calves. Hair dies off when there is insufficient circulation. Also, legs may be cool, pale or purple and the pulse in the foot, ankle or groin is diminished.
Detecting & Diagnosing the Disease
An easy, non-invasive, risk-free test for detection of PAD is the Ankle-Brachial Index (ABI). ABI compares the blood pressure in the arms to blood pressure in the ankles. A normal ABI ratio is .9-1.3. A blockage would be detected if it drops below that number. The lower the ratio, the more concern for blockage.
“ABI helps decide if PAD is present but we really determine if treatment is appropriate based on symptoms,” says Dr. Iafrati. Although a very useful screening tool, the ABI is not perfect as the numbers may be falsely elevated in people with very stiff arteries, as can happen in renal failure or diabetes.
For more specifics on a blockage, a physician may call for imaging: Ultrasound, CT Scan, Angiogram, or MRI.
But, Dr. Iafrati says the most important part of the diagnosis of PAD is the medical history and physical exam of the patient and that’s where the treatment can begin.
Treatment & Prevention
It is important to aggressively identify PAD to maximize medical therapy including daily aspirin, blood pressure and cholesterol control, a statin medication, and an exercise program.
Cilostazol is a medication used to help mobility. While it doesn’t improve overall health or survival, it could increase walking distance.
When these efforts fall short, a vascular specialist may decide to more directly increase the blood flow to the legs. This can be accomplished by bringing blood around the blockages with a bypass operation or by crossing the blockages and opening them with catheter based procedures. Choosing between the various options takes into account many factors including specifics on exactly where the blockage is, how severe and long it is, as well as many patient factors such as the presence of heart disease, prior procedures, etc. Dr. Iafrati and his team use a highly personalized approach, recommending treatments tailored to the specifics of the particular patient.
”In general bypass surgery is considered the most durable procedure for lower extremity PAD, especially when a patient’s own vein is available for the bypass. We expect that about 80 percent of patients will have a functioning bypass to and beyond five years,” says Dr. Iafrati.
Leg bypasses can also be done with prosthetic grafts, which although inferior to a patient’s own vein can be used quite effectively in certain cases where a vein is not available. Advances in these grafts, including the addition of blood thinners to the grafts, have greatly increased their effectiveness in the last few years.
Less invasive catheter based procedures are available to cross and open blockages. These include some combination of ballooning (angioplasty), scraping out the plaque (atherectomy), and/or stenting. These techniques can often be accomplished under local anesthesia as an outpatient procedure and frequently result in excellent short term results. The durability however has not measured up to bypass in many circumstances and the decision as to the best approach is individualized.
In recent years there have also been significant advances in stent technology making them better able to withstand the constant flexing in the legs as well as the addition of drugs to balloons and stents that reduce the risk of forming scar tissue in or at the ends of the stents (intimal hyperplasia).
The best advice is to do all you can to prevent PAD in the first place.
“Exercise and don’t do tobacco, control blood pressure and high cholesterol,” advises Dr. Iafrati.
Fortunately, the future of treatment for patients with Peripheral Arterial Disease is bright. Dr. Iafrati has been involved in three, soon to be four, clinical trials involving the use of bone marrow stem cells in patients with advanced tissue loss that could result in amputation. He calls the research a potential game-changer.
“Though the individual trials are small, when you combine them there appears to be about a fifty percent reduction in the risk of major limb amputations,” says Dr. Iafrati, noting that in one study, pain at rest was reduced, improving the patient’s life. “There is lots more work to do, but the early results are promising.”
Posted September 2017
The above content is provided for educational purposes by Tufts Medical Center. It is free for educational use. For information about your own health, contact your physician.