A prospective, multicentre cohort study of perioperative intravenous contrast administration and the incidence of acute kidney injury in major gastrointestinal surgery

Introduction: This study aimed to determine the impact of preoperative exposure to intravenous contrast for computed tomography (CT) and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.
Methods: This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, reversal of stoma, or liver resection. Both elective and emergency procedures were included. Preoperative intravenous contrast exposure was defined as contrast administration for the purposes of CT imaging up to 7-days preceding surgery. The primary endpoint was the 7-day AKI rate. Propensity score matched (PSM) models were adjusted for patient, disease, and operative variables. Model results are reported with odds ratios (OR) and 95% confidence intervals (CI). In a sensitivity analysis, a PSM model explored association between preoperative contrast exposure and AKI in the first 48-hours following surgery.
Results: A total of 5378 patients across 173 centres were included. Overall, 23.2% (n=1249) of patients received intravenous contrast media. The overall 7-day postoperative AKI rate was 13.4% (718/5378). In the propensity-score matched model preoperative contrast exposure was not associated with 7-day AKI (OR 0.95, 95% CI 0.73-1.21, p=0.669). The sensitivity analysis found no association between preoperative contrast administration and 48-hour postoperative AKI (OR 1.09, 95% CI 0.84-1.41, p=0.498).
Discussion: There was no association between preoperative intravenous contrast administered for CT scans up to 7-days prior to surgery and postoperative AKI. Risk of contrast-induced nephropathy should not routinely be used as a reason to avoid contrast-enhanced CT imaging.