2809 The Role of Serum Total Bilirubin Level Pattern in Predicting Spontaneous Passage of Common Bile Duct Stones

Abstract

INTRODUCTION: In patients with suspected choledocholithiasis, total bilirubin (T. bili) level is widely accepted as a marker of biliary obstruction. We sought to evaluate the role of bilirubin decline pattern and extent in predicting spontaneous passage of stone in patients with suspected choledocholithiasis. METHODS: Patients who were 18 or older and admitted to our institution between October 2015 and December 2017 with ICD 10 code(s) commonly used in patients with confirmed or suspected choledocholithiasis were identified through the University of Kentucky Medical Services Database. Only pts with documented elevated T. bili with at least three measurements 12 hours apart were included for further review. Only pts with high-probability of choledocholithiasis based on very strong and/or strong clinical predictors of choledocholithiasis per ASGE guidelines were included in the final analysis. All selected pts underwent one or more of the following studies: MRCP, ERCP, EUS or IOC during their hospitalizations. Categorical variables were compared using chi square tests and continuous variables using two-sample t-tests. Odds ratios and 95% confidence intervals (CI) were calculated for variables of interest. RESULTS: 825 patients were identified according to the screening criteria. 723 patients were excluded due to having pathologies other than documented or suspected choledocholithiasis and 102 patients (48 males and 54 females) were included in this study. Mean age was 57.4 years +/- 22. Of the 102 patients, 74 (72.4%) were eventually documented to have retained stones requiring clearance. 75 (73%) patients had consistent decline in T. bili ( > 3 measurements) while 33 (27%) had fluctuating levels. In patients with a consistent decline in T. bili, 26 (34.7%) were found to have retained stones while 49 (65.3%) were confirmed to have spontaneous passage of stone based on subsequent study. In comparison, significantly lower number (3; 7.4%) of patients with fluctuating T.bili level had spontaneous passage (OR 6.6; 95% CI 1.5, 30.2; P = 0.06). The mean change of T. bili in patients with and without spontaneous stone passage on day 2 was not significant (1.16 mg/dl +/-2.23 vs. 1.04 mg/dl +/- 1.17, P = 0.78). CONCLUSION: Patients with consistent total bilirubin decline beyond day two after initial presentation were seven times more likely to have had spontaneous passage of bile duct stone regardless of the decline level and can be used to determine need for further diagnostic and/or therapeutic interventions.