Aortic Neck Severity in Endovascular Aneurysm Repair is Determined by Multiple Morphological Characteristics

Abstract

Introduction: The anatomy of the aortic neck influences the outcome of endovascular abdominal aneurysm repair (EVAR) and is defined severe (SPN) when at least one of the following characteristics, length, diameter, angle, and thrombus/calcification hamper a proper proximal sealing.1Aim of this study was to evaluate the individual role ofeach one of these characteristics on early and late EVAR outcomes. Methods: Data were retrieved from a monocentric inhouse database prospectively maintained from January 2012 to July 2018. Anatomical aortic neck risk factors (NRF) considered were short length (< 15 mm), wide diameter (>28 mm), severeb-angle (>60°), severe mural thrombus/calcification (>50%), not cylindrical shape (tapered/reverse tapered), Chaikof aortic neck severity score = 3 (CSS)1and analyzed in terms of early [adjunctive intraoperative aortic cuff (IAC) and neck-related technical success (TS), including type Ia endoleak (ELIa), renal coverage, open-conversion]and late complications [ELIa, freedom from proximal neck-related re-interventions (FFR), survival]. Results: Five-hundreds-ninety-fourpatients (mean age, 75±7 years) underwent elective EVAR for abdominal aortic aneurysm (mean diameter, 57±11 mm). The anatomical proximal aortic neck features are reported in Table 1. Fourteen (2.4%) IAC needed to be deployed during EVAR. By univariate analysis, short neck (p=.005), severeb-angle (p=.03) and CSS (p=.05) were related to IAC, and severe angle was confirmed as independent risk factor at the multivariate analysis (p=.05, 95% CI .117-1.022).Seven (1.1%) ELIa and 1 (0.2%) renal coverage occurred. Overall neck-related TS was achieved in 586 (99%) patients. At the univariate analysis, severe b-angle (p=.003), tapered shape (p=.003) and CSS (p=.003) significantly affected the neck-related TS, with severe b-angle confirmed as the only independent predictor (p=.009, 95% CI 1.634-30.49). At a mean follow-up of 30 ± 22 months, survival was 94%, 85% and 67% at 1, 3 and 5 years, respectively. Thirteen (2.2%) ELIa occurred during follow-up. At the univariate analysis,short neck (p=.005), wide neck (p=.03), severe angle (p=.02), tapered (p=.001) / reversed tapered (p=.02) shape and CSS (p=.004) were risk factors for late ELIa, and short neck (p=.04, 95% CI .081-.958), tapered (p=.001, 95% CI .006 - .268) and reversed tapered shape (p=.034, 95% CI .068 - .900) were independent risk factors at multivariate analysis. Of 34 (5.7%) late reinterventions, 12 (2%) were related to the proximal neck and were associated with severe b-angle (p=.02).Overall FFR was 98%, 95% and 86% at 1, 3 and 5 years, respectively. Severe b-angle was significantly related to IAC (p=.02), neck-related TS (p=.02) and re-interventions(p=.03), only if associated with short neck, and with late ELIa (p< .001) and re-interventions(p< .001) only if associated with wide neck. Conclusion: Severe b-angle is one of the main predictors of early outcomes, due to the higher risk of IAC and neck related TS. However, if it is associated with a neck length >15 mm and diameter < 28 mm is less prone to short- and long-term complications. Differently, ELIa, are mainly influenced by the short and non-cylindrical neck. Our results suggest that the severity of the aortic neck is better defined by the association of several risk factors rather than CSS alone.Table 1Anatomical proximal aortic neck features Disclosure: Nothing to disclose