Renal function-adjusted contrast medium volume is a major risk factor in the occurrence of acute kidney injury after endovascular aneurysm repair

Acute kidney injury (AKI) is a complication that can occur during endovascular aneurysm repair (EVAR), increasing postoperative mortality and disease-related death. We therefore evaluated the incidence of AKI after elective EVAR, as well as related factors affecting AKI occurrence, investigating the volume of contrast medium (CV)/estimated glomerular filtration rate (eGFR) ratio as a predictive factor. We retrospectively reviewed the data of patients who underwent EVAR for infrarenal abdominal aorta aneurysm at a single center between April 2011 and December 2018. AKI was defined according to the Kidney Disease: Improving Global Outcomes criteria. We evaluated the occurrence of AKI within the first 7 days postoperatively, comparing serum creatinine levels, eGFR, CV, CV/eGFR ratio, fluid input and output, and morbidity between the AKI and no-AKI groups. The data of 147 patients were analyzed, of which 131 (89.1%) were males (mean age: 72.10±7.40 years); the incidence of AKI was 4.1% (6/147 patients). The mean dose of contrast agents used was greater in the AKI group than in the no-AKI group (249.17 ± 83.21 mL vs 179.43 ± 84.32 mL, respectively; P = .05). The baseline eGFR was 42.69 ± 22.08 mL/kg/1.73 m(2) in the AKI group and 77.96 ± 18.92 mL/kg/1.73 m(2) in the no-AKI group (P = .001). The CV/eGFR ratio was significantly higher in the AKI group (8.21 ± 6.13 vs 2.46 ± 1.44; P = 0.003). Baseline eGFR (odds ratio [OR] = 0.922, P = .001) and the CV/eGFR ratio (OR = 2.049, P = .008) were observed to be factors related to the occurrence of AKI in the logistic regression analysis for patients’ characteristics, operation-related factors, and renal outcomes. In the receiver operating characteristic curve analysis, the area under the curve of the CV/eGFR ratio was 0.856, indicating the greatest influence. A CV/eGFR ratio cutoff value of 3.84 was considered the most appropriate, with an 83.3% sensitivity and 83.0% specificity. The CV/eGFR ratio, rather than the absolute amount of contrast agents, was associated with the development of AKI after EVAR. The CV/eGFR ratio could be used as a possible indicator to limit the amount of contrast media required for the procedure.