Acute Pancreatitis in Patients After Bariatric Surgery: Incidence, Outcomes, and Risk Factors

Background The incidence of acute pancreatitis (AP) in bariatric surgery patients is not known. Ouraim was to determine the incidence, outcomes, and risk factors of AP in postbariatric surgery patients. Methods An historical cohort study was conducted of all patients who underwent Roux-en-Y gastric bypass, sleeve gastrectomy, adjustable gastric banding, and revisional procedures at our institution from January 2004 to September 2011. Patients who developed AP were identified by review of the electronic medical record. A nested case-control study using Cox regression analysis was done to identify risk factors. Results A total of 2695 patients underwent bariatric surgery. Twenty-eight patients (1.04 %) developed AP during a median follow-up of 3.5 years (interquartile range [IQR] 1.9-5.8). One patient had severe AP, and there was one AP-related death. In the case-control study, the only baseline variable that predicted post-operative AP was a prior history of AP. Three other variables identified after surgerywere associatedwithAP: (1) rapid weight loss as measured by percent of excess weight loss (EWL) at the first post-operative visit, (2) abnormal findings on post-operative ultrasound (stones, sludge or ductal dilation), and (3) postoperative complications of bowel leak or anastomotic stricture. Conclusions The incidence of AP in this cohort is 1.04 %, which is higher than that reported for the general population (similar to 17/100,000, 0.017 %). Most cases were clinically mild and managed conservatively with good outcomes. Rapid postoperative weight loss and the presence of gallstones or sludge on post-operative ultrasound were significant risk factors for AP.