Quantification of suprarenal aortic neck dilation after fenestrated endovascular aneurysm repair

Suprarenal aortic neck dilation (AND) after fenestrated endovascular aneurysm repair (FEVAR) with commercially available devices has not yet been well characterized. The aim of this study was to measure diameter changes in the supravisceral aorta after FEVAR.

This is a single-center retrospective review involving patients with juxtarenal aneurysms treated with Cook ZFEN devices (Cook Medical, Bloomington, Ind). Patients with at least 1 year of cross-sectional radiologic follow-up were included. AND was defined as ≥3 mm at any measured location. 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. The first postoperative CT scan (≤1 month) served as a baseline from which subsequent measurements at annual intervals were compared.

A total of 43 patients who underwent FEVAR from 2012 to 2018 met inclusion criteria, with a total of 119 target vessels (83 renal stents, 41 superior mesenteric artery scallops or large fenestrations). Mean follow-up time was 30.3 months. Any AND was found to occur in 32 (74.4%) patients. Aortic diameter dilation 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 < .0001) to the middle of the second seal stent (1.3 ± 3.8 mm; P < .01). Diameter growth was most pronounced in the middle of the first seal stent, with mean AND of 3.6 ± 3.2 mm. At this location, the aorta experienced nearly linear annual growth of 0.99 mm (95% confidence interval, 0.7-1.28 mm) per year. Increasing device oversizing relative to the native visceral aorta was the strongest predictor of postoperative neck diameter growth (1.34 mm per 10% increase in oversizing; P = .02), whereas increasing proximal seal length was protective of growth (-1.82 mm per 10-mm increase in seal length; P = .016). Proximal seal lengths ≥3 cm were associated with less neck dilation compared with <3 cm (2.6 mm vs 4.9 mm; P = .022). Type IA endoleak in this cohort was rare (n = 1) and not associated with AND (P = .256).

Dilation of the suprarenal aorta is a common finding in midterm follow-up after FEVAR and not associated with proximal endoleak. Aggressive device oversizing is predictive of dilation, whereas longer seal lengths are associated with less dilation along the suprarenal seal zone. These results support the continued use of FEVAR for juxtarenal aneurysms, particularly in patients in whom ≥3 cm of healthy seal length can be obtained.