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 (one to three biopsies), group B (four to six biopsies), and group C (seven to ten 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 4-6 biopsies had a sensitivity of 77.4 %, while the group with 7-10 biopsies had a sensitivity of 70.8 %. The group with 1-3 biopsies had a sensitivity of 34.5 %. Statistically significant differences were observed between the groups, with comparisons showing improved sensitivity in the 4-6 biopsy group versus the 1-3 biopsy group (χ² = 14.42, p = 0.0001), and the 7-10 biopsy group versus the 1-3 biopsy group (χ² = 6.56, p = 0.010).

Conclusions: performing four to six cholangioscopy-guided biopsies significantly improves sensitivity for diagnosing perihilar cholangiocarcinoma compared to one to three biopsies. Further studies are needed to validate these findings.