PYTHAGORAS: Bifurcated stent graft confers durable benefit in patients with AAA, challenging anatomy

At 5 years, a bifurcated stent graft was associated with positive outcomes in patients with abdominal aortic aneurysms and challenging anatomy, according to results from the PYTHAGORAS trial.

Mahmoud B. Malas, MD, associate professor of surgery and director of endovascular surgery at Johns Hopkins Bayview Medical Center, presented the findings at the Society for Vascular Surgery 2016 Vascular Annual Meeting in National Harbor, Maryland.

“The U.S. PYTHAGORAS trial is the first [endovascular aneurysm repair] clinical trial to include a majority of highly angulated (> 60°) infra-renal aortic necks as well as a higher percentage of female patients (29%),” Malas said in a press release issued by Lombard Medical. “Moreover, the suitability of patients to be included was determined by the investigators rather than the company, resulting in many more ‘real-world’ cases being recruited.”

The prospective, controlled, multicenter U.S. trial was designed to evaluate the safety and efficacy of the bifurcated stent graft (Aorfix, Lombard Medical) in treating patients with abdominal aortic aneurysms (AAAs) who had highly angulated aortic necks or tortuous aortoiliac anatomy. According to the release, highly angulated necks have traditionally been associated with worse outcomes in endovascular aneurysm repair (EVAR), as has female sex.

Of the 218 patients enrolled in the trial, 151 had high neck angles. Eighty-seven percent of surviving patients had 5-year follow-up. At 1 year, a core lab adjudicated no reports of type 1 or type 3 endoleaks in any CT imaging.

At 5 years, there were no new cases of type 1 or type 3 endoleak. The group with normal-angle necks had a migration rate of 4% and a sac expansion rate of 4%, whereas the group with higher-angle necks had a migration rate of 5.1% and a sac expansion rate of 15.3%, according to the researchers, who reported that the differences were not statistically significant.

All-cause mortality, aneurysm-related mortality and aneurysm-rupture rates at 5 years were found to be equivalent when compared with the Lifeline registry of U.S. EVAR trials in normal anatomy, according to the release.

At 5 years, freedom from all-cause mortality was 64%, freedom from aneurysm-related mortality was 96.5%, freedom from sac rupture was 98% and freedom from secondary intervention was 81%, Malas and colleagues reported.

“The results attest to the long-term durability of the Aorfix design and support the use of this endovascular option, which is ‘on-label’ even in patients with hostile anatomy, including highly angulated aortic necks,” Malas said in the release. – by Dave Quaile

Reference:

Malas MB, et al. Plenary Session 7/Late-Breaking: SS31. Presented at: Society of Vascular Surgery 2016 Vascular Annual Meeting; June 8-11, 2016; National Harbor, Md.

Disclosure: Malas reports no relevant financial disclosures.