The Type of Bariatric Surgery Impacts the Risk of Acute Pancreatitis: A Nationwide Study

OBJECTIVE: We investigated whether vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass surgery (RYGB) have a differential impact on post-operative risk of acute pancreatitis (AP). METHODS: This retrospective study uses the 2012–2014 National Readmission Database. We compared morbidly obese patients who underwent VSG (n = 205,251), RYGB (n = 169,973), and hernia repair (HR) control (n = 16,845). Our main outcome was rates of AP within 6 months post- vs. 6 months pre-surgery in VSG, RYGB, and HR. We also investigated risk factors and outcomes of AP after bariatric surgery. RESULTS: The rates of AP increased post- vs. pre-VSG (0.21% vs. 0.04%; adjusted odds ratio [aOR] = 5.16, P < 0.05) and RYGB (0.17% vs. 0.07%; aOR = 2.26, P < 0.05) but not post-HR. VSG was associated with a significantly greater increase in AP risk compared to RYGB (aOR = 2.28; 95% CI: 1.10, 4.73). Furthermore, when compared to HR controls, only VSG was associated with a higher AP risk (aOR = 7.58; 95% CI: 2.09, 27.58). Developing AP within 6 months following bariatric surgery was mainly associated with younger age (18–29 years old: aOR = 3.76 for VSG and aOR: 6.40 for RYGB, P < 0.05) and gallstones (aOR = 85.1 for VSG and aOR = 46 for RYGB, P < 0.05). No patients developed “severe AP” following bariatric surgery. CONCLUSIONS: More patients develop AP within 6 months after VSG compared to RYGB and controls. This risk is highest for younger patients and those with gallstones. Prospective studies examining mechanisms and prevention are warranted.