Staples Poised to Change Endovascular Repairs

BY MITCHEL L. ZOLER

BALTIMORE -- A new approach to endovascular repair of abdominal aortic aneurysms that uses staples delivered by a separate catheter to attach an endograft to the vessel was safe in a phase I study with 20 patients.

"Stapling represents a new endovascular technique," Dr. David H. Deaton said at the Vascular Annual Meeting. "Stapling, or transmural fixation, is the first way to attach one object to another using a catheter-based system. It's a new modality that could also apply to other things than vascular grafts."

In addition, "stapling allows changes in graft design, allowing a reduction in the size of delivery catheters because the fixation device is not in the delivery catheter. It also allows the surgeon to position the graft at one point and then change the position at another point." This will help endograft deployment in more tortuous necks, said Dr. Deaton, chief of endovascular surgery at Georgetown University in Washington.

Based on the safety, technical feasibility, and initial treatment success shown by endostaples and this endovascular repair system, the Food and Drug Administration has approved a pivotal, phase II trial that will be done at 25 sites and is schedule to begin this year, Dr. Deaton said. The phase I and II studies are sponsored by Aptus Endosystems Inc., the company that makes the endovascular repair system and the endostaples. Dr. Deaton is a consultant to Aptus. A spokesman for Aptus said that the phase II study will start in August 2007.

The phase I study was designed as a feasibility and safety study with 1 month of follow-up. The 20 patients enrolled were treated at six U.S. centers. The endograft delivery systems were introduced using either 16- or 18-French (Fr) catheters; the endostaples were delivered with a 16-Fr catheter. The staples are made from a metal alloy and have a corkscrew shape that potentially holds both the graft to the aortic wall and the aortic wall to the graft, Dr. Deaton said. The tip-to-tip diameter of the staple is 3 mm.

All of the endograft components were successfully deployed, and attachments were made using a total of 89 staples in the 20 patients. The median number of staples used in a patient was 4, with a range of 2-10.

By 30 days after treatment, three patients (15%) had a type 2 endoleak; there were no other types of endoleaks detected. In two patients, thromboses developed in an arm of the repair device, in one case after 9 days and in the other case after 30 days. None of the patients had adverse events that were related to endostaple use, Dr. Deaton said