Introduction

Strictures of the biliary tract represent a common diagnostic and management problem in pancreaticobiliary practice, often requiring close multidisciplinary collaboration among endoscopists, surgeons, radiologists, pathologists and oncologists. The underlying aetiologies, clinical manifestations and prognostic significance are protean, encompassing both benign and malignant entities; single and multifocal disease distributions; extrahepatic and intrahepatic site involvement; silent and symptomatic presentations, and clinically indolent as well as rapidly progressive natural histories. From a practical standpoint, however, the most critical distinction to make, both accurately and expeditiously, is between benign and malignant aetiologies since timely surgical resection of early-stage malignant disease remains the only route to cure. Definitive differentiation, however, is not always feasible, and many cases remain indeterminate even after extensive investigation.

The differential diagnosis of biliary strictures is predominantly a function of geography and consequent variations in disease epidemiology. In the Western world, most biliary strictures are secondary to malignant disease in the form of pancreatic cancer, cholangiocarcinoma, gallbladder cancer, malignant hilar lymphadenopathy and hepatocellular carcinoma. Important benign aetiologies include iatrogenic causes (usually in the setting of bile duct injury during cholecystectomy) chronic pancreatitis, primary sclerosing cholangitis (PSC) and immunoglobulin G-subfraction 4 (IgG4)-related sclerosing cholangitis (IgG4-SC). Other causes of benign biliary strictures include gallstone disease (choledocholithiasis or Mirizzi syndrome); ischaemic and non-ischaemic injury in the setting of liver transplantation; anastomotic disease after biliary tract surgery; abdominal trauma; percutaneous therapy of hepatocellular carcinoma (radiofrequency or ethanol ablation and chemoembolisation); radiotherapy; portal bilopathy, vasculitides; and miscellaneous infections (such as recurrent pyogenic cholangitis, cytomegalovirus infection and human immunodeficiency virus).

The clinical manifestations of biliary strictures are equally diverse, principally dictated by the severity of luminal obstruction and nature of causative disease process, ranging from being entirely asymptomatic with or without biochemical or radiological features of cholestasis, as in many post-cholecystectomy bile duct injuries, to those of …