Postoperative Renal Dysfunction Independently Predicts Late Mortality in Patients Undergoing Aortic Reconstruction

Abstract

Preoperative chronic kidney disease (CKD) has been shown to predict postoperative renal complications and late survival following aortic surgery, whereas the impact of postoperative renal complications less severe than permanent dialysis are unknown. We evaluated the effect of increasingly severe postoperative renal dysfunction on survival using a regional quality improvement registry. Patients undergoing intact open aortic reconstruction in the Vascular Study Group of New England registry (2003-2012) were stratified by severity of postoperative renal complications; none, creatinine increase >0.5 mg/dL (IncCr), or any dialysis (HD). Predictors of renal dysfunction and impact of renal complications on survival were analyzed using multivariable methods. A total of 2095 patients were included, of which 72% had open abdominal aortic aneurysm repair, and 28% open aortoiliac reconstruction. Of these, 15% of patients had moderate CKD, and 1.2% had severe CKD at baseline. Postoperatuve renal complications were none in 90%, IncCr in 8.6%, and HD in 1.6%. Multivariable cumlogit regression identified moderate CKD (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.8-3.9; P < .01), severe CKD (OR, 17; 95% CI, 7-41; P < .01), operating room time (OR, 1.004 minutes; 95% CI, 1.003-1.006; P < .01), and supra-renal clamp use (OR, 2.1; 95% CI, 1.4-2.9; P < .01) as independent predictors of worsening strata of postoperative renal dysfunction. Risk-adjusted multivariable Cox regression showed that IncCr (hazard ratio, 1.6; 95% CI, 1.1-2.3; P = .01) and HD (hazard ratio, 3.2; 95% CI, 1.8-5.7; P < .01) increased risk of late death independent of age, gender, baseline moderate or severe CKD, congestive heart failure, chronic obstructive pulmonary disease, and postoperative myocardial infarction or death. Five-year survival was lower (log rank P < .01) in patients with IncCr (71% ± 4%), and HD (29% ± 10%) compared with those with none (79% ± 1%; Fig). Increasing severity of postoperative renal dysfunction independently predicts increased risk of late mortality after open aortic surgery. Perioperative measures to reduce renal complications may potentially prolong the survival of patients following open aortic surgery.