Study Identifies Predictors of Renal Dysfunction After AAA Repair

April 19, 2017—A study of the predictors of renal complications after endovascular aneurysm repair (EVAR) and open repair of abdominal aortic aneurysms (AAAs) was published by Sara L. Zettervall, MD, et al in the Journal of Vascular Surgery (2017;65:991–996).

Renal complications after repair of AAAs have been associated with increased morbidity and mortality; however, limited data have assessed risk factors for renal complications in the endovascular era. This study aimed to identify predictors of renal complications after EVAR and open repair.

For the study, patients who underwent EVAR or open repair of a nonruptured infrarenal AAA between 2011 and 2013 were identified in the National Surgical Quality Improvement Project Targeted Vascular module. Patients were excluded if they were on hemodialysis preoperatively. Renal complications were defined as new postoperative dialysis or serum creatinine increase > 2 mg/dL. Patient demographics, comorbidities, glomerular filtration rate (GFR), operative details, and outcomes were compared using univariate analysis between those with and without renal complications. Multivariable logistic regression was used to identify independent predictors of renal complications.

As summarized in the Journal of Vascular Surgery, 4,503 patients were identified for analysis (EVAR, n = 3,869; open repair, n = 634). Renal complications occurred in 1% of patients after EVAR and in 5% of patients after open repair. There were no differences in comorbidities between patients with and without renal complications.

A preoperative GFR < 60 mL/min/1.73 m² occurred more frequently among patients with renal complications (EVAR, 81% vs 37%; P < .01; open repair, 60% vs 34%; P < .01).

Thirty-day mortality was also significantly increased (EVAR, 55% vs 1%; P < .01; open repair, 30% vs 4%; P < .01). After adjustment, renal complications were strongly associated with 30-day mortality (odds ratio [OR], 38.3; 95% confidence interval [CI], 20.4–71.9).

Independent predictors of renal complications included GFR < 60 mL/min/1.73 m² (OR, 4.6; 95% CI, 2.4–8.7), open repair (OR, 2.6; 95% CI, 1.3–5.3), transfusion (OR, 6.1; 95% CI, 3.0–12.6), and prolonged operative time (OR, 3.0; 95% CI, 1.6–5.6).

Elevated baseline GFR, open approach, transfusion, and prolonged operative time were found to be predictors of renal complications. Because of the increased mortality associated with renal complications, renoprotective strategies should be used, transfusions should be limited by achieving meticulous hemostasis, and an endovascular approach should be used when technically feasible, advised the investigators in the Journal of Vascular Surgery.