Manesh Patel, MDPatients over the age of 70, or patients over age 50 who have diabetes or a history of smoking, are at high risk for peripheral vascular disease (PVD) -- but probably don’t know it.

Although more than eight million Americans have this condition, in which atherosclerotic plaque builds up in vessels outside the heart and brain -- most commonly resulting in reduced blood flow to the legs and feet -- many have no symptoms, or they mistake the signs for something else.

Though the disease has long been recognized as an indicator of increased risk for cardiovascular and cerebrovascular disease, some of the recommendations for evaluation and treatment are shifting along with improvements in technology.

Cynthia Shortell, MDDukeMed Magazine asked three specialists to discuss the current options for diagnosis and treatment of PVD:

Manesh Patel, MD, cardiologist and assistant professor of medicine at Duke

Cynthia Shortell, MD, professor of surgery, chief of vascular surgery, and director of Duke’s Center for Vascular Disease

Tony Smith, MD, professor of radiology and division chief of vascular and interventional radiology

Tony Smith, MD

Why should patients with only mild or few symptoms be evaluated and treated for PVD?

Patel: The risks associated with PVD are not solely related to the legs but to the heart and the brain. More than half of people who have PVD also have severe coronary disease. When we take care of patients, our first goal is to reduce the risk for heart attacks and strokes.

While not all patients with PVD will have leg pain, claudication (pain or numbness in the legs that occurs when walking and resolves with rest) is certainly the most common symptom. Any patient with claudication should be evaluated, even if they don’t currently have heart disease, because PVD can be a precursor to heart disease.

Are there other indications besides claudication that my patient may need PVD evaluation?

Shortell: All patients with heart disease, cerebrovascular disease, smoking history, and diabetes are at high risk for having PVD, but the issue of whether or not they should all be screened is controversial. If a patient’s distal pulses are absent on physical exam, they definitely should be evaluated.

My patient has diabetes and already clearly has problems in his small blood vessels. Why would he need further evaluation?

Patel: Even these patients may still benefit from an evaluation of their large blood vessels. Otherwise, it’s like saying your problem is due to blockages in exits off of Interstate 40 without looking at 40 itself.

Opening up the big pipelines can still help these patients, and in many cases stave off amputation. Unfortunately, there are patients who go to amputation without anyone ever evaluating the blood flow to the large vessels in the leg.

When should my patient with PVD be referred for an interventional or surgical procedure?

Shortell: Patients should have failed conservative management before having a catheter-based or surgical procedure. That management is similar to treatment of atherosclerosis and would include aggressive control of blood sugar, lipid-lowering and antihypertensive treatment, antiplatelet therapy, and thorough foot care.

Also, smoking cessation is very important. Smoking has been shown to increase the risk of PVD as much as seven times. A sustained exercise program to build new vessels and improve circulation works the vast majority of the time. But of course, it’s harder to achieve than a procedure.

Sometimes medications can be useful, but we don’t have any medications that are excellent. For example, we have cilostazol (Pletal), which improves blood flow in the vessels. Fifty percent of the patients who take that medication are able to walk 50 percent farther without symptoms.

But many patients who take this drug experience side effects including GI upset, headache, and palpitations, and it’s contraindicated with cardiac arrhythmias and patients who have a history of congestive heart failure.

If a patient is still experiencing symptoms after maximal medical therapy, then she should be referred for a possible surgical intervention.

What has changed in terms of the procedures available for patients who need surgical intervention?

Smith: There are a lot of interventional therapies we can offer for patients who have chronic problems with PVD, including some patients who in the past would have actually gone to amputation.

For instance, we can revascularize the entire lower extremity percutaneously, which means we can open up the superficial femoral artery through catheter-based procedures that use balloons and stents.

Five years ago, we usually revascularized only very short areas of narrowing or occlusion. But today improvements in equipment and skill sets allow us to revascularize much longer segments.

The other option is of course to perform a bypass graft around occluded arteries. or, sometimes hybrid procedures are appropriate. Hybrid procedures can be performed in the cardiac catheterization lab or in the operating room and involve a surgeon making a surgical incision to get into the vessel, then using catheters to open up the vessel without doing a full surgery.

Shortell: In many cases, physicians will want to delay such interventions, because their benefits are durable but not permanent.

For example, in a young patient, a physician may not want to use up the patient’s saphenous vein for a bypass in case the patient were going to need it for a heart or lower leg bypass down the road. We usually reserve bypass for severe cases of claudication, or cases of critical limb ischemia, which means if an intervention isn’t performed, the patient is at risk of losing their leg.

Are there special interventions for these patients at risk for limb loss?

Patel: Duke has formed a Limb Salvage Center for patients who have critical limb ischemia -- which presents as resting leg pain or a non-healing ulcer.

Physicians can contact Duke Vascular, either cardiology, surgery, or interventional radiology, and we’ll see them in clinic and determine if there are ways to get more blood flow to their legs, and also make sure we’re coordinating our efforts with wound care specialists.

As part of the work of that center, for patients who have no other options to get blood flow to their legs, Duke offers enrollment in a clinical trial that uses stem cells to try to generate growth of new vasculature. This trial uses a therapeutic known as Pluristem, which is made up of undifferentiated placental stem cells. These cells are injected into the legs in an attempt to promote growth of new blood vessels and reduce pain for these patients.

What is changing for patients who need interventions for PVD affecting the carotid artery?

Smith: The gold standard of care for carotid artery disease is surgery (endarterectomy), in which an incision is made in the neck and the plaque is physically removed from the artery.

A less invasive option is carotid stenting, which is performed by inserting a catheter into an artery in the groin that is then threaded to the carotid artery. Currently, carotid stenting is approved by medicare and by third-party payers only for patients for whom surgery poses a high risk.

For patients not at high surgical risk, the literature has been inconclusive as to whether stenting provides outcomes that are equal to those from surgery.

But the results of CREST, a major study announced in February 2010 at the American Stroke Association’s International Stroke Conference, may change the playing field. CREST was an NIH-sponsored study with more than 100 centers involved, including Duke.

This was the largest randomized clinical trial to date comparing the two approaches, and it required rigorous training and credentialing for the physicians who performed the surgeries and stenting, in order to get a true comparison between the procedures.

The CREST results showed that carotid stenting essentially works just as well as surgery for patients who would normally undergo endarterectomy). In this trial, the overall stroke rates and long-term effects were similar for both procedures.

These results were a milestone, but at this point, we don’t know how Medicare and insurers will respond. Based on this study, they may in fact open it up and say a patient can choose whichever procedure they want. But we will have to wait a period of months to find out the decision.

Patel: In the meantime, patients who aren’t at high risk for surgical complications may be able to access carotid stenting through another clinical trial at Duke.

I’m the principal investigator at Duke for ACT 1, which is comparing carotid stenting with endarterectomy in treating asymptomatic patients at standard surgical risk. We have enrolled more than 30 patients in this trial and are still recruiting.

How does a doctor know what type of specialist to refer a patient to?

Smith: We have a great multidisciplinary effort between the Departments of Surgery, Medicine, and Radiology here. When patients come to the Duke Vascular Group, they get an opinion from all of us -- non-invasive cardiovascular medicine as well as endovascular and open surgery.

Patel: Sometimes, at other institutions, when you are referred to a surgeon you will most likely get a surgical procedure, or if you go to cardiology, you will get a catheter-based procedure. At Duke, we work together to figure out the best procedure for the patient, if a procedure is needed.

But as a general guideline, patients who have both heart and vascular disease may benefit from seeing a cardiologist first. If a patient has had prior surgical procedures or is considering surgery elsewhere and is at risk for surgical complications related to vascular disease, especially if they have non-healing wounds, they may benefit from a referral to a surgeon.