The Impact of Aneurysm Morphology and Anatomic Characteristics on Long-Term Survival after Endovascular Abdominal Aortic Aneurysm Repair.

Background: Hostile anatomic characteristics in patients undergoing endovascular abdominal aortic aneurysm repair (EVAR) and the placement of endografts not in concordance with the specific device anatomic guidelines (or instructions for use [IFU]) have shown decreased technical success of the procedure. But these factors have never been evaluated in regard to patient postoperative survival. We sought to assess the association between survival and (1) aneurysm anatomy and characteristics and (2) implantation in compliance with manufacturer's anatomic IFU guidelines in patients undergoing endovascular aortic aneurysm repair.

Methods: The cohort included 273 consecutive patients who underwent EVAR at Baylor Heart and Vascular Hospital between January 1, 2002 and December 31, 2009 and had their preoperative computed tomography (CT) scan digitally retrievable. The CT scans and operative notes were then reviewed, and the anatomic severity grading (ASG) score, maximum aneurysm diameter, thrombus width, patency of aortic side branch vessels, and implantation in compliance with IFU guidelines were assessed. The unadjusted association between survival (assessed until November 1, 2011) and these variables was assessed with the Kaplan-Meier method. Moreover, propensity-adjusted (for a comprehensive array of clinical and nonclinical risk factors) proportional hazard models were developed to assess the adjusted associations.

Results: Seven (2.56%) patients died within 30 days from EVAR, and 88 (30.04%) patients died during the study follow-up. Patient mean survival was 6.3 years. The unadjusted analysis showed a statistically significant association between survival and thrombus width (P = 0.007), ASG score (P = 0.004), and implantation in compliance with IFU guidelines (P = 0.007). However, the adjusted analysis revealed that none of the anatomic and compliance factors were significantly associated with long-term survival (ASG, P = 0.149; diameter, P = 0.836; thrombus, P = 0.639; patency, P = 0.219; and implantation compliance, P = 0.219).

Conclusions: Unfavorable aneurysm morphologic characteristics and endograft implantation not in compliance with IFU guidelines did not adversely affect patient survival after EVAR in this group of patients. This implies that unfavorable anatomy, even that which would necessitate implantation of the EVAR device outside of the IFU guidelines, should not necessarily contraindicate EVAR.