Percutaneous transhepatic cholangioscopy reveals epithelial changes in the biliary tract induced by drainage catheters

Percutaneous transhepatic cholangioscopy (PTC) is an endoscopic technique that directly visualizes the biliary epithelium and enables targeted biopsy acquisition to evaluate indeterminate biliary lesions and manage benign and malignant biliary diseases.Its diagnostic and therapeutic applications continue to expand.This case series describes PTC-observed epithelial changes associated with biliary drainage catheters and their histopathologic correlation in four patients with benign biliary disease.Device dwell times ranged from 21 to 390 days.PTC demonstrated diffuse mucosal erythema, marked hyperemia, villous-like papillary projections, and exophytic polypoid granulation tissue in areas of biliary device contact.Targeted biopsies revealed acute and chronic inflammation, exuberant granulation tissue, and subepithelial fibrosis with no evidence of atypia or dysplasia, providing histopathologic correlation with the PTC findings.These changes suggest that exposure to biliary drainage devices may be associated with localized epithelial abnormalities.PTC enabled direct assessment of the biliary epithelium and targeted tissue sampling, allowing endoscopic findings to be correlated with microscopic histopathologic alterations.This approach helps evaluate biliary mucosal abnormalities and characterize epithelial changes associated with indwelling biliary devices.Combining cholangioscopy visualization with histologic assessment may improve understanding of device-related mucosal responses and help distinguish reactive changes from lesions that require further diagnostic evaluation and management.