Endograft platform does not influence aortic neck dilatation after infrarenal endovascular aneurysm repair with primary endostapling.

Abstract

Aortic endografts used for endovascular aneurysm repair (EVAR) are based on varying skeletal platforms such as stainless steel or nitinol stents, using radial force applied to seal at the aneurysm neck, and varying proximal fixation methods, applying either suprarenal or infrarenal fixation. This study assesses whether varying skeleton/fixation platforms affect neck-related outcomes after primary endostapling with Heli-FX EndoAnchors at EVAR. Retrospective analysis of a prospective database of infrarenal EVAR undertaken at a single centre. Chimney-EVAR, secondary cases were excluded. Primary outcomes analysed included neck diameter evolution from pre-EVAR to latest imaging follow-up, including a comparison of stent platforms to see if there was any outcome difference between those using stainless steel or nitinol, as also freedom from type I endoleakage and migration. Secondary outcomes assessed included average number of EndoAnchors, and sac size patterns before and after EVAR. A total of 101 patients underwent endostapled infrarenal EVAR between September 2013 and March 2020. After exclusion of ineligible patients, 84 patients (76 male, 8 female, age 73.7 ± 7.8 years) were available for analysis. 57/27 endografts used suprarenal/infrarenal fixation, whilst 16/68 devices were based on stainless steel/nitinol platforms, respectively. Mean oversizing was higher for stainless steel/suprarenal fixation endografts (p = 0.02). A total of 582 EndoAnchors were deployed, averaging 7 ± 2 per patient. Median neck diameter was 25 mm (IQR 22-31) with 22 necks having non-parallel morphology (conical, tapered or bubble). Median follow-up period was 28.5 (IQR 12-43) months. Neck evolution studies suggested aortic neck dilatation of 5 ± 4 mm (p <0.001, paired T-test), independent of platforms employed (p = NS, ANOVA). There was no endograft migration; one immediate post-EVAR endoleak settled by eight weeks. There was a mean 5.7 ± 8.2 mm sac size reduction (p < 0.001, paired T-test). Aortic neck dilatation occurs after EVAR with primary endostapling, but the process may be independent of stainless steel/nitinol platforms, possibly due to the attenuating effect of EndoAnchors. Adjunct aneurysm neck fixation by primary endostapling prevents migration regardless of whether suprarenal/infrarenal fixation is the primary fixative method. Device platform choice therefore may be left to the operator discretion if primary endostapling is applied at EVAR. Freedom from complications such as migration and endoleakage in the intermediate term suggests a higher level of 'tolerance' to aortic neck dilatation with primary endostapling. We would therefore suggest routine usage of EndoAnchors at EVAR when not otherwise contraindicated.