Acute changes in renal function after laparoscopic gastric surgery for morbid obesity

Background: Acute renal failure (ARF) is a serious complication that contributes to patient morbidity and may result in death. To date, no data are available regarding the predictive risk of ARF or its effect on the outcome of patients who undergo laparoscopic gastric bypass. Methods: The medical records of 1800 patients who underwent gastric bypass from July 1997 to July 2003 at a single institution were analyzed. The data collected included demographics, comorbid factors, operative details, and postoperative outcomes. Multivariant analysis was performed and the results were compared with those of 500 age-, gender-, and comorbidity-matched control patients who underwent similar operations. Results: The mean age was 50 ± 8 years; 23 were men and 19 were women. Of the 1800 patients, 42 (2.3%) developed ARF after surgery. Dialysis was required in 6 patients, 2 of whom became dialysis dependent. ARF completely resolved in the remaining patients. Conclusion: Primary ARF after laparoscopic gastric bypass is an uncommon complication, with an incidence of 2.3% in our institution. Patients with a body mass index >50, previous chronic renal failure, and long operating times and intraoperative hypotension are at the greatest risk of postoperative renal failure. All patients who had normal renal function preoperatively returned to normal renal function within 6 months.