FJVIS 17. Quantification of Suprarenal Aortic Neck Dilation After Fenestrated Endovascular Aneurysm Repair

Abstract

Suprarenal aortic neck dilation (AND) after fenestrated endovascular aneurysm repair (FEVAR) has not yet been characterized. The aim of this study was to measure diameter changes in the juxtavisceral aorta after FEVAR. This is a single-center retrospective review involving patients with pararenal or juxtarenal aneurysms treated with Cook ZFEN devices (Cook, Bloomington, Ind). Patients with at least 1 year of radiologic follow-up were included. Aortic diameter, defined as the average outer-to-outer diameter on three-dimensional centerline imaging, was measured at seven locations along the length of the ZFEN device from the proximal fixation struts to the bottom of the second seal stent (Fig, left). The first postoperative computed tomography scan (≤1 month) served as a baseline with which subsequent measurements at annual intervals were compared. A total of 43 patients who underwent FEVAR met inclusion criteria, with a total of 119 target vessels (83 renal stents, 41 superior mesenteric artery scallops or large fenestrations). Median follow-up time was 30.3 months. AND at latest follow-up was found to occur at all measured locations from the top of the fixation struts (1.9 ± 2.4 mm; P < .001) to the bottom of the first seal stent (3.4 ± 3.3 mm; P < .001). AND was most pronounced in the middle of the first seal stent, with mean AND of 3.6 ± 3.2 mm (Fig). At this location, aortic diameter was found to increase at each interval compared with the baseline scan (mean, 1.4 mm/y). Aortic diameter did not significantly change along the second seal stent (−1.8 to +1.3 mm; P = .08-.1). AND ≥3 mm at any location was found to occur in 32 (74.4%) patients. Increasing device oversizing relative to the native visceral aorta was the strongest predictor of AND (0.34 mm per 10% increase in oversizing; P = .007), whereas increasing length of the seal zone was protective of AND (−1.97 mm per 10-mm increase in seal length; P = .023). Seal lengths ≥3 cm were associated with less AND compared with <3 cm (2.6 vs 4.9 mm; P = .022). However, type IA endoleak in this cohort was rare (n = 1). Dilation of the suprarenal aorta is a common and benign finding in midterm follow-up after FEVAR. Aggressive device oversizing is predictive of dilation, whereas longer seal lengths are associated with less dilation along the suprarenal seal zone.