Limitations of three-dimensional intraductal ultrasonography in the assessment of longitudinal spread of extrahepatic bile duct carcinoma

Abstract

We investigated the utility and limitations of three-dimensional intraductal ultrasonography (3D-IDUS), for the assessment of the extent of longitudinal cancer spread to the hepatic side by extrahepatic bile duct carcinoma. In eight patients with extrahepatic bile duct carcinoma. 3D-IDUS was used to assess longitudinal cancer extension to the hepatic side prior to resection. When the linear dimension of 3D-IDUS showed bile duct wall thickening that was connected to the tumor and which became thin at a point, it was determined to be the front formation of longitudinal cancer extension. The findings were examined in relation to histologic information from the resected specimen. Although 3D-IDUS showed front formation of wall thickening in two patients, it accurately reflected the histological margin of the longitudinal cancer extension in only one patient. In the other patient, the wall thickening was longer than the histological margin. When 3D-IDUS showed bile duct wall thickening without front formation (n = 2), the wall thickening was longer than the histological margin of the longitudinal cancer extension. Even when 3D-IDUS did not show wall thickening (n = 4), one of these patients showed cancer spread histologically. As a result, the accuracy in assessing longitudinal cancer extension by 3D-IDUS was only 50%. Even if the linear dimension of 3D-IDUS demonstrated front formation of thickening of the bile duct, it reflected not only cancer extension but also inflammatory wall thickening.

Ultrasound of the gallbladder and the biliary tree

“…Endoscopic ultrasonography is reported to have sensitivity in detecting bile duct stones >90% and specificity >95% [52]. Similar values are reported for intraoperative and intraductal ultrasonography [53,54,55,56,57,58,59,60]. Magnetic resonance cholangiopancreatography is the only non-invasive technique with very high values of sensitivity and specificity, but it still remains of limited availability in many institutions and of considerable cost.…”

Intraductal ultrasonography (IDUS) for the diagnosis of biliopancreatic diseases

“…It allows the reconstruction of acquired data as a multiplanar display or as a 3-D view, which facilitates easier recognition of cancer spread along the bile duct and the configuration of the tumour and the surrounding structures than what is possible with only cross-sectional two-dimensional (2-D) views. Preliminary data on 3-D IDUS have been reported [46][47][48]. Three-dimensional IDUS requires a thick sheath catheter, over three mm in diameter, to achieve smooth movement of the transducer mounted inside during data acquisition.…”

“…As mentioned above, the longitudinal spread of the bile duct cancer from the main tumour is visualised by IDUS as an irregular and asymmetric thickening of the wall. It is necessary to perform IDUS before establishing biliary drainage as it causes thickening of the bile duct wall, which mimics cancer extension [28, 31,32,45] Although the number of patients included was small, Tamada et al [48] reported the accuracy of IDUS in the evaluation of longitudinal spread of bile duct cancer to be only 50% (four out of eight cases), even with 3-D imaging. Noda et al [45] carried out a comparative study of preoperative IDUS with histological findings in surgical cases with bile duct cancer.…”

Is contrast-enhanced intraductal ultrasonography helpful in the differential diagnosis of a thickened bile duct wall?

“…Although we expected that IDUS could distinguish cancer infiltration from fibrosis, this determination was difficult. Similarly, Tamada et al 13 have reported difficulty in distinguishing bile duct wall thickening due to cancer spread from that secondary to intlammation, using IDUS and 3D-IDUS.…”