Background

Despite the overall safety of metabolic and bariatric surgery (MBS), the potential for postoperative complications such as acute kidney injury (AKI) remains a critical concern. We aim to investigate the incidence of AKI after MBS and the associated risk factors.

Methods

A retrospective review of patients undergoing primary MBS between May 2008 and October 2022 was performed. Determination of AKI was based on postoperative increase in serum creatinine (sCr) by 0.3mg/dL within 72 hours. A conditional logistic regression analysis was performed to identify AKI risk factors.

Results

Among 1697 patients, the incidence of AKI was 3%(n=51). The occurrence of AKI was significantly more likely to occur in patients who had preoperative insulin-requiring diabetes (25.5%vs.15.1%,p=0.04), hypertension (52.9%vs.39.4%,p=0.006) and renal insufficiency (39%vs.4%,p=0.038). Patients with AKI had significantly longer procedure durations (172.5+-71.2 mins) compared to those who did not (150+-56.2 mins)(p=0.03). The odds of AKI were higher in males (aOR=3.63, 95%CI[1.98,6.63]) and patients on therapeutic anticoagulation (aOR=2.41, 95%CI[1.21,5.79]). There was no significant difference in anesthesia medications used and dosages between groups. Among those with AKI, 7 patients (13.7%) required postoperative dialysis, and 3 (5.9%) progressed to chronic kidney disease, with all 3 eventually receiving transplant.

Conclusions

AKI is a rare but serious complication following MBS that occurs in approximately 3% of cases. AKI incidence is higher in male patients, those with hypertension, insulin-requiring diabetes, renal insufficiency, and longer procedure durations. Heightened awareness of the identified risk factors should help guide patient selection, and additional efforts should be directed towards refining postoperative follow-up.