A novel technique for endoscopic transpapillary “mapping biopsy specimens” of superficial intraductal spread of bile duct carcinoma (with videos)

Bile duct cancer (BDC) has a lower propensity for distant metastasis during the early part of its natural history, and local extension into adjacent vessels and longitudinal intraductal extension are of critical prognostic importance. Superficial intraductal spread (SIDS) is a characteristic feature of this tumor and is associated with a more-differentiated phenotype and a less-aggressive clinical course. However, the presence of SIDS correlates with positive resection margins after surgery. Hence, preoperative identification of the exact proximal and distal margins is important for deciding whether the surgical approach should comprise extrahepatic bile duct resection with or without pancreatoduodenectomy (PD) and whether rightor left-sided hepatectomy is needed. Direct cholangioscopic intraductal visualization, with or without narrow-band imaging, is important for evaluating SIDS. Despite these enhanced imaging techniques, stent-induced or cholangitis-induced mucosal changes are often difficult to differentiate from neoplastic involvement in a segment of bile duct, without tissue sampling. The use of intraductal biopsy specimens for diagnosing SIDS of BDC can be performed by percutaneous transhepatic cholangioscopy, but this technique is time consuming, invasive, and might result in cancer seeding. Hence, using an endoscopic route for obtaining transpapillary biopsy specimens may be preferable. Although the use of forceps biopsy in the diagnosis of stenotic bile duct lesions with fluoroscopic targeting or