Endoscopic ultrasound versus endoscopic retrograde cholangiopancreatography-guided biliary drainage for primary decompression of malignant biliary obstruction: protocol for a systematic review and meta-analysis of randomised controlled trials

Introduction Current evidence supporting the utility of endoscopic ultrasound-guided biliary drainage (EUS-BD) as a first-line treatment option for malignant biliary obstruction (MBO) is limited. We plan to provide a systematic review and meta-analysis to compare the performance of EUS-BD and endoscopic retrograde cholangiopancreatography-guided biliary drainage (ERCP-BD) as primary palliation of MBO. Methods and analysis Randomised controlled trials evaluating EUS-BD versus ERCP-BD in primary drainage of MBO will be searched in MEDLINE, EMBASE, Web of Science, the Cochrane Library, ClinicalTrials.gov and Google Scholar, from database inception to 31 October 2018. Data on study design, participant characteristics, intervention details and outcomes will be extracted. Primary outcomes to be assessed are technical and clinical success. Secondary outcomes include adverse events, stent patency, stent dysfunction, reinterventions, procedure duration and overall survival. Study quality will be assessed using the Cochrane Risk of Bias Tool. Meta-analysis will be performed using RevMan V.5.3 statistical software. Data will be combined with a random effect model. The results will be presented as a risk ratio for dichotomous data, weighted mean difference for continuous data and HR for time-to-event data. Publication bias will be visualised using funnel plots. Ethics and dissemination This study will not use primary data, and therefore, formal ethical approval is not required. The findings will be disseminated through peer-reviewed journals and committee conferences. PROSPERO registration number CRD4201811704