Acceptable number of cholangioscopy-guided biopsies for diagnosing perihilar cholangiocarcinoma.

Introduction: Diagnosing perihilar cholangiocarcinoma can be challenging. Previous studies suggest that the sensitivity of taking three cholangioscopy-guided biopsies is approximately 70%. We hypothesized that obtaining four or more biopsies might improve the sensitivity for diagnosing perihilar cholangiocarcinoma.

Objective: To determine the acceptable number of cholangioscopy-guided biopsies to improve sensitivity for diagnosing perihilar cholangiocarcinoma.

Methods: This retrospective study analyzed clinical records of adults with perihilar stenosis who underwent cholangioscopy-guided biopsies. Patients with gallbladder cancer or metastatic bile duct obstruction were excluded. Data were grouped based on the number of biopsies taken: Group A (1 to 3 biopsies), Group B (4 to 6 biopsies), and Group C (7 to 10 biopsies). Results from each group were compared against a composite standard, including clinical follow-up and/or biopsies performed by alternative methods.

Results: The group that underwent 4 to 6 biopsies had a sensitivity of 77.4%, while the group with 7 to 10 had a sensitivity of 70.8%. The group with 1 to 3 biopsies had a sensitivity of 34.5%. Statistically significant differences were observed between the groups, with comparisons showing improved sensitivity in the 4 to 6 biopsy group versus the 1 to 3 biopsy group (χ² = 14.42, P = 0.0001), and the 7 to 10 biopsy group versus the 1 to 3 biopsy group (χ² = 6.56, P = 0.010).

Conclusions: Performing 4 to 6 cholangioscopy-guided biopsies significantly improves sensitivity for diagnosing perihilar cholangiocarcinoma compared to 1 to 3 biopsies. Further studies are needed to validate these findings.