Five-year outcomes of the PYTHAGORAS U.S. clinical trial of the Aorfix endograft for endovascular aneurysm repair in patients with highly angulated aortic necks.

Abstract

Early and midterm outcomes of the Prospective Aneurysm Trial: High Angle Aorfix Bifurcated Stent Graft (PYTHAGORAS) trial in patients with highly angulated aortic necks (≥60 degrees) have already been published and shown comparable outcomes to other endografts in normal anatomy. Herein, we present the long-term outcomes of the PYTHAGORAS trial of Aorfix (Lombard Medical, Irvine, Calif) for patients with highly angulated aortic neck anatomy. The Aorfix endograft is a highly conformable nitinol/polyester device designed for transrenal fixation. The U.S. trial enrolled 218 patients and observed all patients at 1 month, 6 months, and 12 months and then annually for a total of 5 years. Endovascular aneurysm repair (EVAR)-specific complications were compared between the standard-angle (<60 degrees) and highly angulated (≥60 degrees) neck groups at 5 years using standard statistical methods. Kaplan-Meier analysis was performed to evaluate the overall 5-year survival and freedom from aneurysm rupture, aneurysm-related mortality, and reintervention. Of the 218 patients enrolled in the trial, there were 67 patients in the standard-angle neck group (I) and 151 patients in the highly angulated neck group (II). Mean proximal neck angle was 45 degrees in group I vs 83 degrees in group II (P < .001). At 5 years, 87% of surviving patients were followed up. The 5-year EVAR-specific results showed no type I or type III endoleak in either group, 4% migration in group I vs 3% in group II, and 4% sac expansion in group I vs 15.0% in group II (P ≥ .27). The 5-year freedom from all-cause mortality was 69% (73% in group I vs 68% in group II; P = .43); from aneurysm-related mortality, 96% (99% vs 95%; P = .44); from aneurysm rupture, 99% (99% vs 99%; P = 1.0); and from device-related secondary intervention, 83% (88% vs 80%; P = .18). None of these differed between groups. The U.S. PYTHAGORAS trial of the Aorfix endograft is the first EVAR clinical trial to include a majority of highly angulated (≥60 degrees) infrarenal aortic necks and is the first to produce evidence after 5 years of implantation. Despite predictors of worse short- and long-term outcomes, pertinent outcomes were better than or similar to those of trials with less severe anatomy. These results support the use of this "on-label" endovascular option, particularly in patients with highly angulated aortic neck anatomy.