Prognostic Role of Severe Infrarenal Aortic Neck Angulation in Endovascular Aneurysm Repair

Abstract

To investigate whether patients with severe infrarenal aortic neck angulation have worse outcomes than those without severe angulation after endovascular aneurysm repair (EVAR). The HDAS (Healthcare Database Advanced Search) interface developed by NICE (National Institute for Health and Care Excellence) was used to search electronic bibliographic databases. Studies comparing outcomes of standard EVAR in patients with and without severe neck angulation were considered. Pooled outcome estimates were calculated using the odds ratio (OR) or hazard ratio (HR) and 95% confidence interval (CI), using the Mantel–Haenszel or inverse variance method, as appropriate. Random effects models of meta-analysis were applied. The GRADE (Grading of Recommendation, Assessment, Development, and Evaluation) methodology was used to assess the certainty of evidence. Ten studies reporting a total of 7 371 patients (1 576 with severe neck angulation and 5 795 without) were included. The studies reported medium term follow up. No statistically significant difference was found for the primary outcomes (overall mortality: HR 1.27, 95% CI 0.88 – 1.85, low certainty; aneurysm related mortality: HR 1.07, 95% CI 0.80 – 1.44, moderate certainty; aneurysm rupture: HR 1.41, 95% CI 0.66 – 2.99, low certainty). The hazard of type Ia endoleak (HR 1.86, 95% CI 1.32 – 2.61) and re-intervention was higher in patient with severe angulation (HR 1.24, 95% CI 1.01 – 1.54), but there was no significant difference in the odds of adjunctive procedures (OR 1.23, 95% CI 0.48 – 3.11), or the hazard of sac expansion (HR 0.83, 95% CI 0.44 – 1.55) or stent migration (HR 1.22, 95% CI 0.78 – 1.92). Meta-analysis of studies that conducted multiple Cox regression analysis showed no significant difference for any of the primary outcomes. Severe neck angulation may not be a poor prognostic indicator for overall/aneurysm related mortality and rupture in the medium term after EVAR but may increase the risk of late type 1 endoleaks and re-intervention; therefore, patients require close surveillance.