Diagnostic efficacy of a novel rotating brush for endoscopic sampling of malignant biliary strictures: a multicenter prospective study

Objectives: Although cytologic examination of biliary stricture brushings obtained via endoscopic retrograde cholangiopancreatography (ERCP) is commonly used for diagnosing malignant biliary strictures (MBSs), it has low sensitivity. Several new brushes have capabilities that are still being debated. We have developed a novel brush working from conventional back-and-forth movement to rotation in situ (RIS) that may be more efficient for MBS sampling. We aimed to compare the MBSs detection sensitivity of our RIS brush with that of the conventional brush. Methods: In this multicenter prospective study, we enrolled patients who underwent ERCP for suspected MBSs involving biliary stricture brushings obtained via our RIS brush. The historical control group consisted of the 30-brushings arm of our previous randomized trial (patient inclusion, 2018–2020) that employed the study design in the same centers and with the same endoscopists as were utilized in the present study. The primary outcome was to compare the sensitivity and specificity of detecting MBSs via cytologic evaluation of biliary stricture brushings between the two groups. Results: We enrolled 155 patients in the intent-to-treat analysis. Using the same number of brushing cycles, the RIS brush showed a higher sensitivity than the conventional brush (0.73 vs. 0.56, P = 0.003). In per-protocol population, the sensitivity was also higher in RIS brush group than in conventional brush group (0.75 vs. 0.57, P = 0.002). Multivariate analysis revealed that the RIS brush was the only predictive factor for MBSs detection. No significant differences were observed in procedure-related complications between the two groups. Conclusions: The RIS brush was a promising tool for effective and safe MBSs sampling and diagnosis. Further randomized studies are warranted to confirm our results. (Chictr.org.cn, identifier: ChiCTR2100047270).