Figure 5. The changes of endoscopic retrograde cholangiopancreatography (ERCP) findings during the clinical course. ERCP performed 3 weeks after endoscopic nasal biliary drainage (ENBD; 1 month after onset) shows that the stenoses extend to the anterior and posterior sectoral duct roots more clearly (A). A guide wire and a cannula have been inserted to the right anterior sectoral duct. An ENBD tube has been inserted to the left hepatic duct branch. The right posterior sectoral duct is branched from the left hepatic duct upstream of the bifurcation of the right anterior sectoral duct. ERCP performed after treatment by ENBD for stent dysfunction (7 months after onset) shows that the stenosis extends from the left hepatic duct and right anterior branch to the lower end of the common bile duct continuously (B). The right posterior branch is not visualized. A guide wire has been inserted to the left hepatic duct branch. A cannula has been inserted to the common bile duct.