Long-Term PYTHAGORAS Data Presented for Lombard Medical's Aorfix Bifurcated Stent Graft

June 13, 2016—Lombard Medical, Inc. announced the presentation of findings from PYTHAGORAS, the Prospective Aneurysm Trial: High Angle Aorfix Bifurcated Stent Graft, at the Society for Vascular Surgery’s 2016 Vascular Annual Meeting, which was held June 8–11 in National Harbor, Maryland. The Aorfix device is intended for the endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms. 

PYTHAGORAS is a prospective, controlled multicenter trial in the United States that is designed to evaluate the safety and effectiveness of the Aorfix endograft for the treatment of highly angulated aortic necks or tortuous aortoiliac anatomy. The United States PYTHAGORAS trial enrolled 218 patients of which 151 had high neck angles; 87% of surviving patients were followed-up at 5 years.

According to Lombard Medical, the core lab reported no type 1 or type 3 endoleaks in any annual computed tomography imaging follow-up after the first year. At 5 years, 60% of angled neck patients had significant aneurysm sac shrinkage. Low-angle patients had similar outcomes, illustrating the tolerance of Aorfix to extreme angulation.

All-cause mortality, aneurysm-related mortality, secondary intervention, and aneurysm rupture rates over 5 years were compared with the Lifeline Registry of United States EVAR trials in normal anatomy and were found to be equivalent. There were no significant differences between Aorfix results in standard and highly angulated necks.

In the company’s press release, Mahmoud B. Malas, MD, commented, “The United States PYTHAGORAS trial is the first EVAR clinical trial to include a majority of highly angulated (> 60º) infrarenal aortic necks as well as a higher percentage of female patients (29%). 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. Angulation alone has been associated with worse outcomes in EVAR and unfortunately, female EVAR patients usually have complication rates that far exceed those of males. These factors and the addition of ‘real-world’ anatomy made the study group of patients highly challenging from many perspectives.”

Dr. Malas continued, “Pertinent outcomes were better than or similar to trials that did not have these risk factors. 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.” Dr. Malas is Associate Professor of Surgery and Director of Endovascular Surgery at Johns Hopkins Bayview Medical Center in Baltimore, Maryland.