Predictors of Decline in Renal Function 5 Years after EVAR

Introduction While there exists copious short-term data regarding renal function following infra-renal endovascular abdominal aortic aneurysm repair (EVAR), long-term analysis is sparse. This is a single institution retrospective review of predictors of renal function decline 5 years after elective EVAR. Methods All EVAR between 2007 and 2015 were queried. Patients in whom renal function was documented 5 years postoperatively were included in analysis. Exclusion criteria were ruptured aneurysm, mortality before 56 months, lack of follow-up, ESRD status, and concomitant renal intervention. The primary outcome investigated was a 20% or greater drop in glomerular filtration rate (GFR) 5 years postoperatively. The following variables at the time of surgery were investigated as potential predictors: age, gender, hypertension, hyperlipidemia, diabetes, CAD or prior MI, COPD, prior stroke, baseline eGFR under 60 mL/min/1.73 m(2), supra-renal fixation, infra-renal fixation, neck diameter, neck length, and number of contrast CT. Results 354 EVAR were identified of which 143 met inclusion criteria (211 excluded). Univariate analysis revealed female gender (OR 2.7), hypertension (OR 9.4), baseline renal insufficiency (OR 3.8), larger neck diameter, and supra-renal fixation (OR 2.32) all predictive (P < .05) of GFR drop at 5 years. Multivariate binary logistic regression analysis found female gender (multivariate OR 3.9, P = .023) and baseline renal insufficiency (multivariate OR 3.0, P = .029) as significant predictors of greater than 20% GFR drop at 5 years. Only 2 patients of the 143 progressed to dialysis requirement at 5 years. Conclusions Females and patients with baseline renal insufficiency are more vulnerable to significant decline in renal function 5 years following EVAR. Consistent with analogous literature, supra-renal fixation appears moderately deleterious toward renal function with no clinical significance in those with baseline normal renal function. The potential benefit of avoidance of supra-renal fixation in female patients with baseline renal insufficiency is worth further investigation in a more robust multi-center study.