Acute Pancreatitis in Patients with a History of Bariatric Surgery: Is It Less Severe?

Introduction: Bariatric surgery (BSx) leads to weight loss and causes alterations in gastrointestinal and pancreatic peptides. This raises questions on acute pancreatitis (AP) occurrence and outcomes in this cohort of patients. We aim to assess mortality, morbidity, and resource utilization of AP in patients with BSx. Methods: Observational retrospective cohort study (2012–2016) with propensity score match. Patients with a principal diagnostic ICD9-10CM code for AP were included. Stratification for the coexistence of history of BSx was performed. The primary outcome was mortality. Secondary outcomes were morbidity, resource utilization, length of hospital stay (LOS), total hospital charges, and costs. Results: Out of 920,615 AP patients, 15,345 had undergone BSx. After propensity matching, 8220 patients with BSx had AP. The mortality for AP was 0.42 (p < 0.01) and for biliary AP 0.29 (< 0.04) in the history of BSx group compared to patients without BSx history. Acute kidney insufficiency (AKI), shock, ICU, multiorgan failure, ERCP, costs, charges, and LOS were all lower for patients with AP who had history of BSx. Patients with biliary AP showed even lower odds of AKI, ICU, multiorgan failure, costs, charges, and LOS, but higher odds of cholecystectomy. Conclusion: Patients with AP with history of BSx have lower mortality, morbidity, and resource utilization. This may be due to post-surgical alterations in pancreatic and gastrointestinal functions including hormonal and anatomical changes. Interestingly, patients with biliary AP and BSx had even lower odds of mortality and morbidity than patients with non-biliary AP, suggesting an added benefit with milder disease course.