Laser Prevents Diabetes Amputation

Feb. 14, 2006 -- A laser technique that uses ultraviolet energy to restore blood flow to blocked arteries may help people with advanced diabetes avoid one of the most devastating complications of the disease -- amputation.

A study on the laser technique included mostly people with diabetes and those with high blood pressure at high risk for losing a limb because of severe diffuse atherosclerosis of the legs. These patients were considered poor candidates for bypass surgery -- the gold standard treatment for prevention of limb loss.

Fewer than one in 10 ended up having a foot or leg removed within six months of having the laser procedure.

Washington Hospital Center interventional cardiologist John Laird, MD, who led the study, tells WebMD that without the laser intervention as many as half of the patients would probably have lost a limb during that time.

"This laser definitely seems to have a role to play in treating patients with the very worst disease who are facing amputations," he says.

Diabetes and Amputation

Diabetes-associated nerve and circulatory damage is the leading cause of lower limb amputation in the U.S., accounting for more than half of all foot and leg removals each year.

According to the American Diabetes Association, 82,000 people lose a foot or leg to diabetes annually.

Saving limbs involves improving circulation, but many people with diabetes are poor candidates for surgery to bypass or improve blood flow because of many factors.

Conventional Lasers vs. New Technology

Conventional, heat-guided lasers were used briefly in the 1980s to burn away blockages. But the technique was quickly abandoned because the heat of the laser was too damaging to surrounding tissue.

The new device, known as the excimer laser, relies on flexible fiber optic catheters to deliver short bursts of ultraviolet energy. The laser is able to precisely target and vaporize blockages without damage to the surrounding artery. This unique feature helps reduce the potential for complications such as clot formations after the surgery. After the laser procedure, balloon angioplasty is performed on almost all patients to help open the once-blocked artery.

In the study, only nine of 119 patients at high risk for amputation ended up losing a limb within six months of having the laser procedure. About half of the patients also got stent implants, which act as scaffolding to prop damaged arteries open.

Laird says results from balloon angioplasty alone tend to be poor in patients like the ones in the study who had severe artery disease with many blockages along the length of the artery.

The study is published in the latest issue of the Journal of Endovascular Therapy. It was funded by the medical device company Spectranetics, which markets the laser.

Managing Disease

Peter Sheehan, MD, tells WebMD that the excimer laser and other nonsurgical options for restoring blood flow to compromised limbs are increasingly being used in patients with advanced disease who are at high risk for amputation. Sheehan specializes in the treatment of diabetes-related lower limb complications. He is director of the Diabetes Foot and Ankle Center for New York University Medical Center's Hospital for Joint Diseases Orthopaedic Institute.

Another catheter device, known as the SilverHawk plaque excision system, shaves blockages from artery walls with a tiny rotating blade and removes them from the body.

"As physicians become more comfortable with techniques like the excimer laser and the SilverHawk, I think we will see them used more in these patients at the highest risk," he says.

But he adds that there is concern that even minimally invasive procedures are being used too often in patients with less severe disease, who may benefit more from making lifestyle changes and taking the right medications.

"Controlling diabetes, cholesterol, and blood pressure with aggressive drug treatment -- along with appropriate exercise and diet -- can help patients avoid these problems in the first place," he says.