Incidence of and risk factors for delayed acute kidney injury in patients undergoing colorectal surgery

Abstract Background The risk of delayed AKI (AKI development beyond the perioperative period) in patients undergoing colorectal surgery is greater than that in patients undergoing other major operations. However, the characteristics of and risk factors for delayed AKI are unclear. Methods We investigated 683 patients who underwent colorectal surgery with intestinal resection at a single tertiary hospital. All patients were followed-up for a year postoperatively. The primary outcome was the development of AKI during follow-up. Results AKI occurred in 177 (25.9%) during the first postoperative year. Patients who developed AKI were significantly older, showed a lower body mass index, and significantly lower preoperative hemoglobin and serum albumin levels. AKI occurred most commonly during the first 3 months postoperatively. However, AKI occurred persistently even after this initial period. Older age, lower preoperative serum albumin levels, and late ostomy closure were independently associated with a higher risk of delayed AKI. Conclusion AKI commonly occurs beyond the perioperative period. Careful risk stratification and modification of risk factors may prevent delayed AKI in patients undergoing colorectal cancer surgery.