Results of the Italian Collaborators for EVAR (ICE) Registry on Acute Kidney Injury After Elective Endovascular Aortic Repair of Infrarenal Abdominal Aortic Aneurysm

Abstract

The aim of this study was to analyze the incidence and predictive factors of postoperative acute kidney injury (AKI) after elective standard endovascular aortic repair (EVAR) in a large recent, multicenter cohort. This is a multicenter, retrospective, financially unsupported physician-initiated observational cohort study. Between January 2018 and March 2021, only patients treated with elective standard EVAR for infrarenal noninfected abdominal aortic aneurysm were analyzed. Patients already on hemodialysis (HD) were excluded. AKI was defined as an increase in serum creatinine (SCr) ≥0.3 mg/dL within 48 hours or an increase in SCr to ≥1.5 times baseline known or presumed to have occurred within 7 days, or a urine volume of <0.5 mL/kg/h for 6 hours. AKI severity stage was classified according to the Acute Kidney Injury Network (AKIN) criteria. Primary outcomes were AKI incidence at 30 days and freedom from HD at 1 year of follow-up. Secondary outcomes were freedom from severe postoperative complication, and freedom from aorta-related mortality (ARM) at 1 year. We analyzed 526 patients (86.5%). There were 489 males (93%) and 37 females (7%): the median age was 76 years (interquartile range, 3-8 years). AKI was observed in 17 patients (3.2%): it was classified as AKIN stage 1 in 12 (2.3%), AKIN stage 2 in three (0.6%), and AKIN stage 3 in two (0.2%). Renal replacement therapy was needed in four (0.8%): HD in three (0.6%, transitory in 2), and continuous veno-venous hemofiltration in one (0.2%). Binary logistic regression analysis identified chronic kidney disease (odds ratio [OR] 4.68; 95% confidence interval [CI], 2.10-10.45; P < .001), and the presence of renal artery stenosis (OR, 3.80; 95% CI, 1.35-10.66; P = .011) to be associated with an increased risk of postoperative AKI. Freedom from ARM was 99.2% at 1 year. Both serum creatinine and estimated glomular filtration rate were significantly different in comparison with preoperative and postoperative level. Of the patients who developed AKI postoperatively, 15 (88.2%) did not require further renal replacement therapy at 1 year; only two patients (0.4%), who already required HD postoperatively, remained on renal replacement therapy by HD at 1 year. Mortality at 1 year was higher in patients who developed postoperative AKI (18.7% vs. 5%; OR, 5.63; P = .051). AKI after elective standard EVAR still occurs but with an acceptably low incidence rate. Preoperative chronic kidney disease is the most important predictor for postoperative AKI, which was not associated with the need of HD at 1-year follow-up but with a higher propensity of mortality.