Mortality Rates of EUS-Guided Biliary Drainage (EUS-BD) in Malignant Biliary Obstruction Patients in EUS-BD Era versus Non-EUS-BD Era: A Retrospective Cohort Study

Abstract

Introduction: Most of the Cholangiocarcinoma (CCA) patients are commonly found in an advanced stage and often presents with Malignant Biliary Obstruction (MBO). Palliative treatment using biliary drainage plays a major role in the treatment modalities. However, only a few studies with small number of subjects have reported their long term outcomes. Aim: To compare the mortality rates of MBO patients in Endoscopic Ultrasound-guided Biliary Drainage (EUS-BD) era versus non-EUS-BD era. Materials and Methods: The present study was a retrospective cohort study which enrolled 132 MBO patients who had received palliative treatment between January 2014 to August 2020 at Thabo Crown Prince Hospital, Nong Khai, Thailand. The patients were treated either with EUS-BD (group l, n=30) or non-EUS-BD (group ll, n=94). Due to imbalance of follow-up time between two groups, the Overall Survival (OS) rates were compared using parametric survival analysis with restricted mean difference at 12 months follow-up, adjusted by other covariates, and presented in term of Kaplan-Meier curve, Hazard Ratio (HR) and 95% confidence interval. Results: Most of the patients (99.19%) were having CCA. The clinical characteristics between the two groups showed no significant difference, except the mean follow-up time that group II was shorter than group I (2.43 vs. 7.12 months; p<0.001). At 12 months after treatment, the OS rate of group I remained significantly higher than group II (mean difference=2.23; 95%CI: 0.54-3.92; p=0.010). The parametric-Cox proportional hazard model showed that the 1-year mortality of patients in group I were 63% less than those in group II, the parametric model between two groups showed statistical significance with p-value=0.043. Conclusion: From present study it can be concluded that EUS-BD in MBO patients achieves lower mortality rate at one year follow-up. For conclusive findings of the benefit of EUS-BD, a prospective long term study with larger numbers of subjects should be performed.