Endovascular TAA Repair Followed

By Mitchel L. Zoler

PHILADELPHIA -- The early advantages of endovascular repair of thoracic aortic aneurysms, compared with open surgery, were maintained during an average follow-up of nearly 3 years in a study of over 200 patients, said Dr. Michel S. Makaroun at the Vascular Annual Meeting, sponsored by the Society for Vascular Surgery.

During follow-up periods of up to 4 years, about 55% of 140 patients treated with an endovascular device were free from major adverse events, compared with about 25% of patients treated by open repair via thoracotomy. And aneurysm-related deaths occurred in 4% of the endovascular-repair patients, compared with 10% of those repaired with open surgery, said Dr. Makaroun, professor of surgery and chief of vascular surgery at the University of Pittsburgh.

The patients that he evaluated had been enrolled in either of two studies that had been sponsored by Gore to test the TAG endovascular device that the company markets for repairing thoracic aortic aneurysms. Perioperative results from these studies, done at 16 centers in the United States, led to approval of the device by the Food and Drug Administration in May 2005.

Dr. Makaroun is a consultant to and has received research support from Gore.

The studies included 140 patients treated with the TAG device, either the initial model or a second, reduced porosity model that was introduced in 2003 to lower the risk of aneurysm growth following repair (the reduced porosity model is the one that received FDA approval). The studies also included 94 patients who underwent an open repair.

The patients were not randomized. Most who underwent open repair in the studies had an aortic anatomy that was not suitable to endovascular repair, such as a proximal neck that was too short (less than 2 cm). But there were also other reasons for open repair, such as the presence of aneurysm symptoms or a lack of enthusiasm by the surgeon for an endovascular approach.

The primary, short-term end point, the rate of combined, major adverse events within the first 30 days after surgery, was 28% in the endovascular group and 70% in the open-surgery group, a statistically significant result. After 4 years of follow-up, patients in the endovascular group had an average of 1.7 major adverse events per patient, compared with an average of 2.9 major events per patient in the open-surgery group.

The total number of reinterventions was 14 in the endovascular group and 9 in the open-surgery group. After up to 5 years of follow-up, five patients in the endovascular group required an aneurysm-related revision, a rate of 3.6%.

The 5-year, cumulative rate of endoleak events in the endovascular group was 17%, with 8% occurring during the first year after surgery. Most of the endoleaks were type I, blood flow between the wall of the stent graft and the aneurysm's wall; four endoleaks were type II, retrograde flow from collateral branches, Dr. Makaroun said.