Long-Term Influence of Suprarenal or Infrarenal Fixation on Proximal Neck Dilatation and Stentgraft Migration After EVAR

BackgroundWe evaluated the influence of the proximal fixation systems of stentgrafts on proximal inter-renal or infrarenal aneurysm neck dilatation after endovascular repair of abdominal aortic aneurysms. Anatomic and clinical predictive factors of neck dilatation and stentgraft proximal migration were searched for.Material and MethodsTaking account of a prospective and monocenter register, 58 patients’ files, with a complete minimum 3-year follow-up, were analyzed after treatment with stentgrafts with a suprarenal fixation (SRF: 33 Talent) or an infrarenal fixation (IRF: 25 AneuRx). Both groups were compared in terms of inter-renal neck dilatation (D1: diameter between the two renal arteries), infrarenal neck dilatation (D2: 7-mm diameter under the lowest renal artery), and specific complication (proximal migration, endoleak). The diameter measured on the last control computed tomography scan was compared with the postoperative diameter. Neck dilatation was defined by a diameter increase exceeding 3 mm and by the proximal migration due to a caudal displacement of the stentgraft ≥10 mm. Predictive factors of proximal migration or neck dilatation were searched for (anatomy of the neck, aneurysm anatomy, stent graft oversize percentage, demographic factors).ResultsPreoperatively, both groups were comparable in terms of anatomic and demographic characteristics of the aneurysm. Mean follow-up was longer in the AneuRx group (62 ± 17 months vs. 53 ± 13 months, p = 0.045) and the percentage of stent graft oversize was greater in the Talent group (18 ± 6% vs. 13 ± 5%, p < 10−4). Freedom from a dilatation exceeding 3 mm in D1 and D2 did not bring any significant difference between the two groups. In each group, the remodeling of the aneurysmal sac (AneuRx median = −4 mm, Talent median = −5 mm, p > 0.05) was only moderately related to proximal neck remodeling. A small angulation of the neck and a smaller neck were the only predictive factors of neck dilatation found respectively in D1 (p = 0.007) and in D2 (p = 0.022). Stent graft proximal migration was more frequent in the AneuRx group (p = 0.031) and was more frequent with large aneurysms (p = 0.029).ConclusionIn the long term, the absence of proximal stent graft fixation system on the dilatation of the aneurysm proximal neck enhances proximal migration. Conversely, the inter-renal or infrarenal proximal neck dilatation does not depend on the type of proximal fixation but on anatomic factors and on the natural evolution of the aneurysmal disease.