Transpapillary intraductal US prior to biliary drainage in the assessment of longitudinal spread of extrahepatic bile duct carcinoma

Background: The utility of intraductal US via the transpapillary route prior to biliary drainage in the assessment of longitudinal extension of extrahepatic bile duct carcinoma was investigated. Methods: In 19 patients with extrahepatic bile duct carcinoma who underwent surgical resection, an ultrasonic probe (diameter, 2.0 mm; frequency, 20 MHz) was inserted into the bile duct via the transpapillary route prior to biliary drainage. Longitudinal cancer extension along the bile duct was prospectively determined and compared with the histologic findings in the resected specimens. Results: Results on the hepatic side were as follows: Intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 9 of 19 patients with one instance of overdiagnosis. The accuracy of intraductal US in assessing the extent of spread (84%) was superior to that of cholangiography (47%) (p < 0.05), Results on the duodenal side were as follows: In patients with suprapancreatic bile duct cancer (n = 14), intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 8 of 14 patients. The accuracy of intraductal US in assessing the extent of the spread (86%) was superior to that of cholangiography (43%) (p < 0.05). Conclusions: Transpapillary intraductal US prior to biliary drainage is useful in demonstrating longitudinal extension of bile duct cancer. However, the surgical margins were inaccurate in some patients.