Published on September 13, 2007 at 2:51 AM
A new vibrating catheter breaks through clogged arteries like a jackhammer, obliterating total blockages in patients with dangerous chronic total occlusions (CTOs).
CTOs develop over time as plaque build-up thickens on the arterial walls, ultimately closing off the artery and preventing oxygenated blood from reaching the patient's leg or foot. This condition left untreated leads to limb amputation.
“These blockages are notoriously difficult to treat without surgery,” said Dr. Imran Mohuiddin, vascular surgeon at the Methodist DeBakey Heart Center in Houston. “This new device gives our patients an effective, minimally-invasive solution that can keep them out of the operating room.”
The tip of the catheter vibrates against the face of the CTO at a frequency of 20,000 cycles per second, pulverizing it and creating a channel through the blockage. High-frequency vibrations also create micro-bubbles in the surrounding fluid of blood and saline. These micro-bubbles expand and implode, producing liquid jets that help to disrupt the surface of the CTO.
“Once the high-frequency vibration breaks through the blockage in the artery, we can then perform standard balloon angioplasty and stent placement. For many patients, this approach eliminates the need for surgical bypass of the blockage,” Mohuiddin said. “Opening these long-standing CTOs is very beneficial to a patient's long-term survival and overall health.”
Results from two Phase I clinical trials demonstrate the device, called the Crosser Catheter System, can be highly effective. In separate U.S. and European studies, FACTOR and CRAFT, respectively, blood flow to limbs was dramatically improved. Both studies exclusively enrolled patients with long-standing blockages in whom previous attempts using conventional catheter-based treatment had failed. Historically, the success rate for treating this type of patient was as low as 30 percent. The Methodist DeBakey Heart Center is currently enrolling patients in the Phase II clinical trial called PATRIOT, which will study this device in 85 patients nationwide.