CHARACTERIZATION OF BILIARY STRICTURES USING INTRADUCTAL ULTRASONOGRAPHY - COMPARISON WITH PERCUTANEOUS CHOLANGIOSCOPIC BIOPSY

Background: We determined the accuracy of intraductal ultrasonography (IDUS) in distinguishing between bite duct cancer and benign bile duct disease. Methods: Patients (n = 42) who required bile duct biopsy usi ng percutaneous transhepatic cholangioscopy (PTCS) to evaluate bile du ct strictures or filling defects were studied. A thin-caliber ultrason ic probe (2.0 mm diameter and 20 MHz frequency) was inserted into the bile duct, and its images were prospectively reviewed before PTCS. Res ults: Disruption of the bile duct wall structure, seen on IDUS, was as sociated with malignancy in 25 of 26 patients. When IDUS demonstrated a lesion with normal bile duct structure, six of nine patients were fo und to have no malignancy. IDUS demonstrated no intraductal lesion in seven patients, and bile duct biopsy also did not indicate cancer in a ny of these patients. The accuracy, sensitivity, and specificity of ID US for diagnosing bile duct cancer were 76%, 89%, and 50%, respectivel y. When used in tandem with IDUS, the sensitivity of bile cytology (64 %) and PTCS (93%) improved to 96% and 100%, respectively Conclusions: The accuracy of IDUS for diagnosing bile duct cancer was less than tha t of PTCS (95%). However, the sensitivity for bile cytology, or bile d uct biopsy improved when performed in combination with IDUS.