Peripheral arterial disease has symptoms that include cramping and leg pain especially as the legs are moved. Some patients experience pain while sleeping. Plaque build-up in the leg arteries causes low blood flow to the legs and results in pain or other symptoms. Without treatment, open wounds may form and a patient can have severely reduced mobility.
Cardiovascular Systems, Inc., a vascular-device company in St. Paul, created the Diamondback 3600, a minimally invasive catheter system that removes plaques from arteries with a diamond-coated “sanding disk” attached to a flexible drive shaft. With diameters of 1.25 to 2.25 millimeters, the Diamondback can reach smaller arteries than similar devices and arteries below the knee.
A doctor injects a special dye and, once it’s circulated, scans the legs to see which arteries need the treatment. The Diamondback enters the body through a small incision in the groin area and then travels to the area needing plaque removal. The procedure takes three to eight minutes depending on the number of sites to be cleared and the hardness of the plaque. David Martin, president and CEO of Cardiovascular Systems, says it is a mostly pain free procedure, patients can have the procedure done under local anesthetic, and about 50 percent of patients can go home the same day. Martin says more than 8,000 people were treated with the Diamondback device in 2008.
“Calcium builds up in your arteries,” Martin says. “Seventy-five percent of those patients with peripheral artery disease below the knee have heavy calcium. Calcium is crunchy and hard. There’s no solution for it right now.” Although there is no way to prevent the build up of calcium or plaque, sanding it off is a relatively effective way to remove it—only 2 percent of patients treated with the Diamondback need to have an artery redone.
What happens with the plaque once it’s removed? “The [plaque] comes off the arterial wall little by little as a very small microparticulate, and it’s absorbed by the capillary system,” Martin says. The device creates particles that are smaller than red blood cells.
Martin says his 237-employee company is seeking FDA premarket approval for a product to treat coronary artery disease. “One reason that this device has been so successful is because of the research and development talent in the Minneapolis area,” Martin says.