The Impact of History of Bariatric Surgery on Acute Cholangitis Mortality and Other Outcomes: A 10-Year Nationwide Analysis

Abstract

Introduction: Gallstone formation following rapid weight loss after bariatric surgery (BS) has been observed, with subsequent occurrence of acute cholangitis (AC). However, the complex post-surgical anatomy limits the possibility of performing an ERCP as part of AC treatment. Therefore, the aim of this study was to assess the impact of bariatric surgery on mortality and resource utilization among patients with AC using a national database. Methods: This was a case-control study using the National Inpatient Sample 2004-2013, the largest publically available inpatient database in the US. All patients with an ICD-9 CM code for a principal diagnosis of AC were included. There were no exclusion criteria. Patients with a past history of BS were identified using the appropriate ICD-9CM codes. The primary outcome was all cause mortality. The secondary outcome was resource utilization: use of ERCP, cholecystectomy, length of hospital stay (LOS), total hospitalization charges and costs (adjusted for inflation). Multivariate regression analyses were used to adjust for the following confounders: Age, sex, race, income in patients' zip code, Charlson Comorbidity Index, hospital region, location, size and teaching status. Results: A total of 106,500 patients with AC were included in the study, of which 1,361 (1.3%) had BS. The mean patient age was 61 years and 49% were female. After adjusting for confounders, patients with and without history of bariatric surgery did not display a statistically significant difference in adjusted odds of mortality (aOR: 0.55, 95% CI: 0.08-3.91, P=0.55). In terms of resource utilization, patients with bariatric surgery had an expectedly lower adjusted odds of ERCP (aOR: 0.36, 95%CI: 0.25-0.52, P<0.01), but similar odds of cholecystectomy (aOR: 1.45, 95%CI: 0.88-2.42, P=0.14). Both patient groups had similar LOS (adjusted mean difference: -0.33 days, 95% CI: -0.93-0.26, P=0.27), total hospitalization costs (adjusted mean difference: -$692, 95% CI: -$2512 - $1128, P=0.46), and charges (adjusted mean difference: -$2865, 95%CI: -$9472 - $3742, P=0.40). Conclusion: A history of bariatric surgery was not associated with different odds of inpatient all-cause mortality among patients who develop acute cholangitis, despite its association gallstone acute pancreatitis and limited ERCP performance. In addition, bariatric surgery does not affect resource utilization in this patient population as measured by length of stay and total hospitalization costs and charges.Table: Table. Adjusted means and odds ratio of evaluated parameters in patients with cholangitis that had a past surgical history of bariatric surgery, compared to patients with no history of bariatric surgery