Acute Pancreatitis (AP) in Post-bariatric Surgery (BRS) Status: Analysis of National Trends, Complications, and Outcomes 2007-2011: ACG Obesity Award

Abstract

Introduction: Rates of BRS are increasing, and post-BRS patients have a high incidence of gallstones for which biliary intervention (ERCP) can be difficult. There are no studies addressing rates and outcome of AP in patients with BRS. Methods: The Nationwide Inpatient Sample (2007-2011) was reviewed for all adult patients (≥18 years) with primary diagnosis of AP. All patients with history of BRS admitted with AP (BRS-AP) were identified. BRS patients with pregnancy were excluded. ICD-9-CM codes were used to identify patients with AP (577.0) and history of BRS (V45.86). Univariate analysis was performed for demographics, hospital factors, and etiologies of AP. A multivariate analysis correcting for variables with p<0.05 was utilized to compare outcomes of complications, mortality, length of stay (LOS), and total hospitalization charges. Results: There were 1,349,842 admissions for AP, and patients with BRS accounted for 1.07% (n=14,386) of all admissions. There was a significant increase in prevalence of BRS among patients admitted with AP (0.73% to 1.39% over 5 years; p<0.001; Cochran-Armitage test). Univariate analysis comparing BRS-AP to non-BRS AP revealed differences in demographics, hospital factors, and etiologies. BRS-AP was more frequently observed in women (82.5% vs. 47.5%; p<0.01), gallstone-related AP (24.8% vs. 22.4%; p<0.01), and in those with obesity (BMI >30 kg/m2, 37.5% vs. 9.8%; p<0.01), while non-BRS AP was more frequent with alcohol related etiology (20.9% vs. 17.1%; p<0.01). Due to post-BRS anatomical changes, BRS-AP patients underwent fewer ERCPs (4.2% vs 7.7%; p<0.01) albeit more cholecystectomies (14.1% vs. 11.9%; p<0.01). After adjusting for patient, hospital, and etiological factors, complications of AP inclusive of pseudocyst (5.8% vs 3.2%; OR 1.61; 95% CI 1.23, 2.08), respiratory failure (3.4% vs. 1.3%; OR 2.70; 95% CI 1.85, 3.85) and acute kidney failure (7.8% vs. 3.9%; OR 1.41; 95% CI 1.14, 1.72) were all associated with non-BRS AP. The mortality rate although lower for BRS-AP did not reach significance (0.22% vs 0.96%; OR 0.5; 95% CI 0.23, 1.16). However, adjusted LOS (4.4 vs. 6.3 days; p <0.01) and total hospital charges ($28,200 vs. $ 31,600; p<0.01) were significantly lower in BRS-AP patients. Conclusion: Gallstone-related AP was more common in patients with BRS. Although rates of admissions for BRS-AP are increasing and ERCP is challenging, these patients have shorter length of stay, lower hospital charges, and lower AP-related morbidities compared to non-BRS patients.