Aortic neck evolution after endovascular repair with TriVascular Ovation stent graft

Objective: Aortic neck dilation has been reported after endovascular aneurysm repair (EVAR) with self-expanding devices. With a core laboratory analysis of morphologic changes, this study evaluated midterm results of aortic neck evolution after EVAR by endograft with no chronic outward force. Methods: This was a multicenter registry of all patients undergoing EVAR with the Ovation endograft (TriVascular, Santa Rosa, Calif). Inclusion criteria were at least 24months of follow-up. Standard computed tomography (CT) scans were reviewed centrally using a dedicated software with multiplanar and volume reconstructions. Proximal aortic neck was segmented into zone A (suprarenal aorta/fixation area), zone B (infrarenal aorta, from lowest renal artery to the first polymer-filled ring), and zone C (infrarenal aorta, at level of the first polymer-filled ring/sealing zone). Images were analyzed for neck enlargement (≥2mm), graft migration (≥3mm), endoleak, barb detachment, neck bulging, and patency of the celiac trunk and superior mesenteric and renal arteries. Results: Inclusion criteria were met in 161 patients (mean age, 75.2years; 92% male). During a mean follow-up period of 32months (range, 24-50), 17 patients died (no abdominal aortic aneurysm-related death). Primary clinical success at 2years was 95.1% (defined as absence of aneurysm-related death, type I or type III endoleak, graft infection or thrombosis, aneurysm expansion >5mm, aneurysm rupture, or conversion to open repair). Assisted primary clinical success was 100%. CT scan images at a minimum follow-up of 2years were available in 89 cases. Patency of visceral arteries at the level of suprarenal fixation (zone A) was 100%. Neither graft migration nor barb detachment or neck bulging was observed. None of the patients had significant neck enlargement. The mean change in the diameter was 0.18± 0.22mm at zone A,-0.32± 0.87mm at zone B, and-0.06± 0.97mm at zone C. Changes at zone B correlated significantly with changes at zone C (correlation coefficient, 0.183; P= .05), whereas no correlation was found with zone A (correlation coefficient, 0.000; P= 1.0). Conclusions: No aortic neck dilation occurred in this series at CT scan after a minimum 24-month follow-up. This may suggest that aortic neck evolution is not associated with EVAR at midterm follow-up when an endograft with no chronic outward radial force is implanted.