Optimizing Outcomes of Single-Operator Cholangioscopy-Guided Biopsies Based on a Randomized Trial

BACKGROUND & AIMS: Although single-operator cholangioscopy is considered to be the most sensitive method for tissue acquisition in patients with indeterminate bile duct strictures (IBDS), methods are needed to optimize the specimen collection and processing techniques. We aimed to determine the optimal method for specimen processing and identify the number of biopsies required to establish a definitive diagnosis. METHODS: Patients with IBDS were randomly assigned to groups that underwent specimen processing using the onsite (n = 32) or offsite (n = 30) method. The primary outcome was to compare operating characteristics of onsite vs offsite specimen processing techniques. The secondary outcome was number of biopsies needed to establish definitive diagnosis. A final diagnosis was established at surgery or after a minimum clinical follow-up period of 18 months RESULTS: The final diagnosis was benign disease in 33 patients and malignancy in 29 patients. There were no significant differences between the offsite and onsite groups in diagnostic accuracy (90% vs 87.5%; P=.99), sensitivity (76.9% vs 75%; P=.99), specificity (100% vs 100%; P=.99), positive predictive value (100% vs 100%; P=.99), or negative predictive value (85% vs 80%; P=.99). Although diagnoses were established by analysis of a median of 1 biopsy in the onsite cohort (interquartile range, 1-1.5), the diagnostic accuracy was identical (90%) in each group, regardless of whether 3 or 4 biopsies were collected from each patient in the offsite cohort. CONCLUSIONS: In a prospective comparative study, we found that centers without onsite cytopathology support that analyze 3 single-operator cholangioscopy-guided biopsies of a biliary stricture and process the specimens offsite make the correct diagnosis for 90% of cases.