Rate of suitable cases for primary EUS-guided biliary drainage in distal malignant biliary obstruction

Abstract

Endoscopic ultrasound (EUS) has been suggested as the primary modality in lieu of endoscopic retrograde cholangiopancreatography (ERCP) for drainage of malignant distal biliary obstruction. However, the presence of a dilated bile duct (≥12 mm) is a prerequisite for the success of the EUS approach. In a retrospective study, we found that 44.9% of 439 ERCP patients over a 3-year period had insufficiently dilated bile duct that was not conducive for an EUS-based intervention. 29 patients were treated by a salvage EUS approach, with median bile duct diameter of 16 mm (IQR 13–18 mm). Although indispensable as a rescue technique, adopting current techniques and technology, this study does not suggest a universal primary role for EUS in this setting. Although ERCP is the preferred therapeutic strategy for malignant distal biliary obstruction, duodenal invasion by tumour can limit technical success. Also, stent dysfunction from tumour ingrowth and post-ERCP pancreatitis are well recognised limitations. Since the early 2000s, EUS-guided biliary drainage (EUS-BD) has emerged as a promising treatment alternative for ERCP. The ability to bypass tumour invasion and avoid instrumentation of the pancreatic duct increases the likelihood of technical success and minimises risk for pancreatitis. A recent meta-analysis of six randomised controlled trials (RCT) comparing EUS and ERCP involving 570 subjects found that patients undergoing EUS-BD required fewer reinterventions and had reduced risk of postprocedure pancreatitis.1 Given these promising observations, it has been suggested that EUS could potentially replace ERCP as the primary treatment modality. However, technical manoeuvres such as accessing the bile duct using a 19-gauge fine needle aspiration (FNA) device to enable guidewire passage or cauterised delivery tip to facilitate lumen-apposing metal stent (LAMS) placement require the presence of a dilated common bile duct (CBD). In two of six RCTs, CBD diameter of ≥12 mm was specified as eligibility criteria …