The Usefulness of IDUS-Guided Transpapillary Bile Duct Biopsy for the Diagnosis of Malignant Biliary Strictures

Background/Aim: Tissue acquisition is the essential for the management of biliary strictures. Fluoroscopically guided transpapillary bile duct biopsy during ERCP may allow the diagnosis of malignancy with limitation by a low sensitivity. IDUS produces a high quality cross sectional image that is useful for the characterization of biliary stricture and can provide optimal biopsy forceps positioning. We compared the diagnostic yields of IDUS-guided transpapillary bile duct biopsy with those of fluoroscopically guided biopsy in tissue diagnosis of malignant biliary stricture.

Methods: From 2007 through 2009, Forty three patients (26 men, mean age 66.5 years) with suspicious malignant biliary stricture by ERCP were enrolled. After ERCP, fluoroscopically guided transpapillary bile duct biopsy followed by IDUS guided biopsy was performed. The IDUS probe remained in that position during and after IDUS guided biopsy. Malignant biliary stricture was classified polypoid, or sessile tumor by morphology on IDUS. The histological examination of the biopsy specimen was performed prospectively by GI pathologist. Reference standards for comparison were surgery, a biopsy confirming malignancy, or the clinical course during follow-up in cases without histopathologic proof of malignancy. The cancer detection rates of IDUS-guided transpapillary bile duct biopsy were evaluated and compared with those of fluoroscopic guided biopsy.

Results: Malignant biliary stricture was diagnosed in 39 of 43 patients with 34 bile duct cancers, 3 pancreatic carcinomas, and two metastatic cancers. IDUS-guided transpapillary bile duct biopsy is technically feasible for bile duct sampling. The cancer detection rate was 26 of 39 (66.7%) using fluoroscopically guided biopsy and 34 of 39 (87.2%) with IDUS-guided biopsy in patients with malignant biliary stricture. For intraductal sessile bile duct tumor, a correct preoperative diagnosis with IDUS-guided bile duct biopsy was significantly higher than the accuracy of fluoroscopically guided biopsy. There is no significant complication after transpapillary bile duct biopsy.

Conclusion: Significantly higher diagnostic yields can be obtained by IDUS guided transpapillary bile duct biopsy compared with fluoroscopically guided biopsy in patients with suspected malignant biliary stricture. We are expecting new type of IDUS probe or accessories for IDUS-guided bile duct biopsy.