Characterization of dominant bile duct stenoses in patients with primary sclerosing cholangitis using intraductal ultrasound

Background & Aims: Primary sclerosing cholangitis (PSC) is associated with the development of cholangiocarcinoma (CC) in approximately 9% of patients. Cholangiography or endoscopic tissue sampling does not reliably allow to distinguish CC from a benign dominant bile duct stenosis. The aim of the present study was to assess the value of intraductal ultrasound (IDUS) in discriminating between benign and malignant dominant stenoses in PSC patients.

Methods & Patients: Forty PSC patients with dominant bile duct stenoses were prospectively studied. Transpapillary IDUS and endoscopic tissue sampling were performed in addition to endoscopic retrograde cholangiography (ERC). Cholangiography as well as the IDUS findings were classified as malignant or benign by the investigators. Final diagnosis of malignant stenosis was based on positive histology and/or cytology, whereas benign character was assumed in cases of negative tissue sampling and uneventful extended clinical follow-up.

Results: Eight PSC patients (20%) had dominant bile duct stenoses caused by CC, whereas 32 of 40 patients (80%) had benign dominant bile duct stenoses. IDUS was significantly superior to ERC for detection of malignancy in terms of sensitivity (87.5% vs. 62.5%, p<0.05), specificity (90.6% vs. 53.1%, p<0.05), accuracy (90% vs. 45%, p<0.05), positive predictive value (70% vs. 25%, p<0.05), and negative predictive value (96.7% vs. 85%, p<0.05). Transpapillary IDUS is more sensitive and specific for characterization of malignant bile duct stenosis compared with endoscopic brush cytology.

Conclusion: Transpapillary IDUS significantly increases the ability to distinguish malignant from benign dominant bile duct stenoses in patients with PSC.