Limb-Saving Laser

New vascular treatment at Genesis may prevent amputation

DAVENPORT, Iowa - The patient has diabetes, and poor circulation prevents the wounds on her lower leg from healing. Blood supply below the knee is severely blocked. All arteries are obstructed, save for one that’s about 99 percent closed.

It’s a typical story of how legs, ankles and toes can be lost to amputation.

But in this real-life case, cardiologist Nicolas Shammas, M.D., is thrilled to have a new tool in the fight against peripheral artery disease -- and amputation.

In the Catheterization Lab at Genesis Medical Center, Davenport, he uses a laser-tipped catheter to vaporize total blockages in the leg and foot arteries that cannot be penetrated by standard catheter guidewires, the small flexible wires used to position catheters.

Called CliRpath, or Cool Laser Revascularization for Peripheral Artery Therapy, the technology restores straightline blood flow in tiny arteries below the knee that have long been difficult to open with other methods.

Developed by Spectranetics Corp, the excimer laser produces an intense light beam that is delivered with great precision through fiber-optic catheters to a small area of tissue. The catheter, made of tiny silica fibers (each the width of a human hair), aims short bursts of "cool" ultraviolet energy to remove the obstruction in the artery.

"We were able to open that single artery with the laser and restore blood supply straight down to the patient’s foot," Dr. Shammas says after the procedure. "I have no doubt that this will bring a tremendous advantage for wound healing."

The new technology is a significant milestone for people with critical limb ischemia, the most severe form of peripheral arterial disease and the frequent culprit of diabetic amputations.

People with diabetes are prone to amputation because the condition often causes blood vessels in the foot and leg to narrow. That leads to poor circulation; increases their susceptibility to infection; and, makes it difficult for wounds to heal.

"We now have an option that is scientifically proven and reliable," says Dr. Shammas of Cardiovascular Medicine, P.C. "Studies show that with this technique, at least 90 percent of people with very advanced disease had preserved limbs after one year. Without this treatment, typically half of these patients would lose their legs.

"This is a dramatic improvement compared to the devices we’ve had. We can’t save every limb, but a 90 percent success rate is incredible. This is a huge deal for our patients."

Saving limbs

Critical limb ischemia affects 1 million people in the United States each year. Without treatment, this restricted blood flow can lead to pain in the legs while at rest and the development of wounds or open sores called ulcers. For 100,000 of those people each year, the disease results in the loss of their toes, feet or the entire leg.

"If you look at national statistics, almost 97 percent of amputations happen because of blood supply blockages in the lower legs," Dr. Shammas says. "We know that the rate of amputation in the U.S. is not going down; it’s actually going up. Diabetes is now an epidemic, and a serious problem for us now and down the road. This technology is going to help a lot of people."

Indeed, there has been a sharp rise in amputations. The Centers for Disease Control found that the number of diabetes-related lower limb amputations increased by 227 percent from 1980 to 2003.

Doctors have long struggled with how to open up the tiny blocked arteries of the lower leg. "These are very small vessels and are typically calcified. They are very hard to treat with conventional treatment," Dr. Shammas says.

Because the arteries are so small and difficult to reach, opening them with balloon angioplasty, small metal coils called stents or small rotating cutters hasn’t worked well. Below-the knee bypasses do not last long, and the surgical risk is high for patients who often have diabetes.

Dr. Shammas is troubled that about half of amputations in the U.S. occur without a single measurement of blood supply down to the lower legs. "No one should be sent for an amputation for a non-healing ulcer or pain in the lower legs without a thorough evaluation of their blood supply and then a decision should be made based on that," he stresses.

"It needs to be a multi-disciplinary approach – one that involves the Wound Care Center, the podiatrist, the orthopaedic surgery, the vascular specialist, the health care nurse. This is a unique specialty that really requires collaborative involvement from various specialties to get the best outcome."

Cool laser revascularization is another tool, particularly for people with diabetes who have blockages that extend far down into the ankle.

"That’s where the laser offers the best advantage over anything else," Dr. Shammas says. "Now we can actually laser those arteries and open up channels in them. We can restore blood supply to areas that have been deprived, and hopefully save limbs."

Warning signs

In peripheral artery disease, plaque blocks foot or leg arteries, resulting in pain, the development of ulcers and infection that can lead to limb loss.

According to the American College of Cardiology, common symptoms are: