Medical Device Daily

Medtronic's (Minneapolis) Talent thoracic stent graft is safe and effective compared to open surgery, according to research published by the Society for Vascular Surgery (SVS; Chicago) in this month's Journal of Vascular Surgery. The FDA approved the device in June (Medical Device Daily, June 6, 2008) for certain aneurysms of the descending thoracic aorta, but it has been available outside the U.S. since the late 1990s.

"The Talent thoracic device, first of all, carries a legacy of experience. It is the most implanted thoracic device in the world; it has been available outside the U.S. since 1997," Simona Zannetti, MD, senior director of clinical affairs for Medtronic Endovascular Innovations, told Medical Device Daily.

The Talent system is designed to provide a minimally-invasive treatment alternative to open surgery for patients with life-threatening aneurysms in the upper portion of the aorta, the body's largest artery. Thoracic aneurysms affect about 30,000 people a year in the U.S., causing thousands of deaths (MDD, March 6, 2007).

The procedure involves threading the stent graft through a small opening in the femoral artery of the leg. The graft is advanced under fluoroscopic guidance to the site of the thoracic aortic aneurysm, where it is then positioned and deployed from the delivery system. Once deployed, the stent graft expands to fit snugly within the diameter of the aorta, providing a new path for the blood flow.

Ronald Fairman, MD, professor of surgery, chief of the division of vascular surgery at the Hospital of the University of Pennsylvania (Philadelphia) and national principal investigator, reported the results of a prospective, non-randomized, multi-center, pivotal trial conducted at 38 sites. The VALOR trial enrolled 195 patients and 189 patients were identified as retrospective open surgical subjects. Endovascular enrollment occurred between December 2003 and June 2005 and endovascular results were compared with retrospective open surgical data from three centers of excellence.

Zannetti, a vascular surgeon, told MDD that there was a statistically significant difference between the 2% 30-day mortality rate in the device group and the 8% 30-day mortality rate in the control group. At 12 months, the aneurysm-related mortality was about 3% in the device group, she said.

Growth prevention of the aneurysm demonstrated the effectiveness of the device, she said, with the rate of stable or decreasing aneurysm diameter at almost 92%. Also, 194 patients (99.5%) had a successful vessel access and deployment of the Talent graft at the intended site, according to the study results.

Medtronic noted that the submission of these pivotal trial results led to FDA approval of the Talent thoracic stent graft system for the treatment of thoracic aortic aneurysms.

Zannetti said the wide diameter range from 22 mm to 46 mm — of Medtronic's Talent thoracic stent graft makes the device unique compared to competing devices because it makes thoracic endovascular aortic repair accessible to an additional 25% of patients.

The FDA recently added stent grafts for aneurysms of the thoracic aorta to the list of high-risk devices it expects manufacturers to track for the lifetime of the device. This class of devices joins stent grafts for abdominal aortic aneurysms, prostheses for temporomandibular joint disorder and a host of devices intended for cardiovascular disease on the list that the agency wants makers to keep track of for as long as the device is in the patient (MDD, Aug. 22, 2008). A Medtronic spokesperson told MDD last week, however, that the company's tracking policy already covers this class of devices so the new guidance would not impact its procedures.

Medtronic is already working on bringing its next-generation thoracic device, the Valiant thoracic stent graft, to the U.S. and is enrolling patients in the VALOR II study for that device. The Valiant has been available outside the U.S. since August 2005, according to the company.