Objective  To explore the value of endoscopic balloon dilatation combined with endoscopic biliary brushings in the diagno-sis of bile duct strictures.

  Methods  A prospective single center study was conducted to summarize the clinical and follow-up data of patients with malignant biliary stricture who were confirmed by CT or MRI during January 2018 to January 2020. All of them were informed consent to endoscopic retrograde cholangiopancreatography (ERCP) procedure. All the patients were treated with endoscopic balloon dilatation of bile duct stricture. Before and after dilation, pathological samples were taken as control group and experimental group. All the pathological diagnosis was made by the same two senior pathologists after reading and discussing the results of cytology. If there are cancer cells or significant heterogenous cells, it indicates that the brush test is positive. Otherwise, it is negative. Among the negative patients, those who still highly considered cholangiocarcinoma and agreed to surgery and confirmed cholangiocarcinoma after surgery or who were difficult to be diagnosed as cholangiocarcinoma progressed after 2 months of follow-up were considered as false negative. The advantage test (McNemar test) was used to analyze the difference between the two diagnostic methods.

  Results  A total of 39 cases were included, 26 males and 13 females, with an average age of (68.0±5.2) years. 35 cases of cholangiocarcinoma were considered by pathology, surgery or 2 months-follow-ups. In the control group, 17 cases were brush positive, and the sensitivity rate was 48.6% (17/35). In the experimental group, 26 cases were brush positive, and the sensitivity rate was 74.2% (26/35). In addition, 2 patients in the control group were brush positive, while in the experimental group, brush negative. A total of 28 cases were positive in the two groups. The sensitivity rate of cell brush test was 80.0% (28/35). There was significant difference between the two groups (P < 0.05).

  Conclusions  Endoscopic balloon dilatation combined with endoscopic biliary brushings can improve the sensitivity of pathological diagnosis of cholangiocarcinoma, and endoscopic biliary brushings before and after balloon dilatation can improve the sensitivity of diagnosis, and the procedure is relatively easy to master and worth spreading in clinical works.