Assessment of predictors of acute kidney injury and progression to chronic kidney disease following bariatric surgery

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. Decade-old studies from our institution reported rates of AKI following MBS between 5.8% and 8.6%, with factors such as higher body mass index (BMI), diabetes, and hypertension identified as potential contributors. However, the incidence and factors associated with AKI following MBS have remained underexplored in contemporary literature.

Objectives: To investigate the incidence and risk factors associated with postoperative AKI, as well as the potential for progression to CKD and renal failure.

Setting: Quaternary academic medical center with a high-volume MBS practice.

Methods: A retrospective review of adult patients undergoing primary laparoscopic MBS between 2008 and 2022 to identify patients who developed AKI, defined as postoperative increase in serum creatinine (sCr) by .3 mg/dL within 72 hours. A multivariable logistic regression was constructed to identify potential AKI risk factors.

Results: Among 1697 patients, the incidence of AKI was 3.0% (n = 51). The distribution of AKI was not significantly different between procedure types. There was no significant correlation between anesthesia medications given and the occurrence of AKI. Male gender was the most significant predictor of AKI (adjusted odds ratio [aOR] = 3.87, 95% confidence interval {CI} [2.14-6.99]), followed by hypertension (aOR = 2.12, 95% CI [1.03-4.83]) and longer surgical duration (aOR = 1.19, 95% CI [1.05-1.35]) per 30 minutes. Of those who developed AKI, 7 (13.7%) required dialysis acutely for management, while 3 patients (5.9%) progressed to chronic renal failure and required 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.