First U.S. Patient Treated in Study of Lithotripsy for Peripheral Artery Disease

High-pressure sound waves disrupt calcified plaque

The first patient in the United States has been treated in a trial assessing the safety and efficacy of a new approach to removing blockages in leg arteries. The Shockwave Medical Lithoplasty System (PinnacleHealth CardioVascular Institute) uses high-speed pressure waves (lithotripsy) to disrupt the plaque and calcium deposits involved in peripheral artery disease (PAD). PinnacleHealth operates three acute-care hospitals in central Pennsylvania.

The ongoing DISRUPT PAD III trial is the largest randomized study to exclusively enroll patients with calcified PAD. The study’s objective is to determine the optimal therapy for dilating heavily calcified lesions by comparing the Shockwave system with traditional angioplasty, with the primary goal of achieving less than 30% residual stenosis without the need for stenting. In addition, all patients who do not receive a stent will be treated with a drug-coated balloon. The study will enroll 334 patients at up to 45 global sites.

PAD is the narrowing or blockage of vessels that carry blood from the heart to the extremities. Caused by the buildup of plaque and calcium within the walls of arteries, PAD occurs primarily in the legs but can be found in vessels throughout the body. 

Balloon angioplasty involves inflating a balloon within the artery at the area of narrowing and expanding the artery to alleviate the blockage. Many patients do not respond well to angioplasty alone, with failure rates as high as 50%, often due to hardened calcium within the wall of the artery.

Lithotripsy uses high-speed pressure waves to disrupt calcium and has been used for years in treating patients with kidney stones. The Shockwave system delivers localized lithotripsy for the treatment of calcified arteries in patients with PAD. Built on an angioplasty balloon platform, each catheter incorporates multiple lithotripsy emitters, which are activated by touching a button while the integrated balloon is inflated. Once activated, these emitters produce therapeutic sound waves that are inherently tissue-selective. The waves pass through the balloon and soft vascular tissue to create a series of microfractures in calcified plaque. Once the calcium has been disrupted, the vessel can be effectively dilated using low pressures, thereby enabling even historically challenging PAD patients to be treated effectively and with minimal injury to the vessel, PinnacleHealth claims.

Source: PR Newswire; April 5, 2017.