Indeterminate Biliary Strictures

Abstract

No standard definition for indeterminate biliary stricture exists. Biliary strictures are typically referred to as indeterminate in cases with nondiagnostic lab work, cross-sectional imaging, and brushings and/or intraductal biopsies obtained during endoscopic retrograde cholangiopancreatography (ERCP) or in cases of benign results but a strong clinical suspicion of malignancy. Indeterminate biliary strictures pose a diagnostic challenge for endoscopists. This diagnostic dilemma can either delay surgical intervention and targeted treatment for malignant lesions or results in unnecessary surgical resections in patients with benign strictures. A benign cause is found in approximately 15–24% of surgical resections for presumed malignant strictures (Bowlus et al., Nat Rev Gastroenterol Hepatol 13:28-37, 2016; Singh et al., Gastroenterol Rep (Oxf) 3:22, 2015). Traditional diagnosis using ERCP with brush cytology and fluoroscopic-guided biopsies lacks sensitivity and precision in distinguishing between benign or malignant lesions. Diagnostic accuracy of malignancy has improved with the combination of newly discovered circulating tumor markers, advancement in ancillary cytology, targeted tissue acquisition techniques, and better-quality imaging and endoscopic modalities including peroral cholangioscopy (POC), intraductal endoscopic ultrasonography (IDUS), and confocal laser endomicroscopy (CLE). Despite these advancements, up to 20% of biliary strictures remain indeterminate after additional evaluation and ultimately undergo surgical intervention for definitive diagnosis (Bowlus et al., Nat Rev Gastroenterol Hepatol 13:28-37, 2016). No standard approach to evaluating a patient with an indeterminate biliary stricture exists. Often, multiple modalities and repeat procedures are required to achieve a definitive diagnosis. This chapter discusses the various modalities that may be utilized in working up an indeterminate biliary stricture.