Diagnosis for the cancer extension of cholangiocarcinoma. The current status

Described is the diagnosis for the cancer extension of cholangiocarcinoma by various imaging techniques and processes to support the current surgical procedure based on preoperative biliary drainage. The cancer tends to locally extend horizontally and/or vertically and its diagnosis is important for surgical indication. For the indication, multi-detector raw CT (MDCT) and MR cholangio-pancreatography (MRCP) are useful and particularly, the former can give multi-phase (arterial, portal and delayed) images to reconstruct multiplanar (MPR) and CT angiographic 3D images, which have made the previous invasive examinations like angiography and percutaneous transportal contrasting unnecessary. MDCT and MRCP can almost complete the diagnosis of the extension. The operative procedure is decided dependently on the site of the lesion, and of which diagnosis, whether it is hepatic hilar/on upper bile duct or middle/lower ductal, is different. MDCT-MPR and MRCP are virtually satisfactory for the former lesion site and more exactly for the horizontal spread, retrograde contrasting cholangiography through indwelled endoscopic naso-biliary drainage (ENBD) and intraductal US (IDUS) are recommended. For the latter middle to lower duct, endoscopic US and IDUS are efficient and more exactly, peroral cholangioscopy is useful. Trained experts able to deal with the complex biliary lesions and specialized facilities are needed. (T.T.)