Feasibility of ex vivo single-operator cholangioscopy in liver grafts

I read with interest the article by Ly et al.1 describing ex vivo cholangioscopy in discarded human liver grafts during cold static storage and normothermic machine perfusion (NMP). Biliary complications remain a major cause of morbidity after liver transplantation, and real-time assessment of the biliary tree before implantation remains an unmet clinical need. In this context, the authors should be commended for proposing an innovative approach for direct biliary visualization during organ preservation and expanding the potential applications of single-operator cholangioscopy.2

The principal novelty of this study lies in being the first report of successful ex vivo cholangioscopy of human liver grafts. The authors demonstrated technical feasibility in eight discarded grafts using a modified single-operator cholangioscopy platform and further extended the approach to cholangioscopy-guided biopsy, confocal endomicroscopy, and anatomical guidance during ex vivo liver splitting. They observed luminal debris and dull mucosa during cold storage, with hyperemic, heterogeneous, and mottled ductal appearances after reperfusion in NMP.

This study has clear strengths, including its originality, the use of human grafts, practical procedural details, and the integration of histological and confocal correlates. However, several caveats should be emphasized. The sample size was very small, all grafts were discarded, and no grafts underwent transplantation; therefore, the findings cannot be linked to biliary outcomes or clinical utility. Furthermore, it remains uncertain whether the hyperemic, heterogeneous, and mottled ductal appearances after normothermic reperfusion are clinically meaningful ischemia/reperfusion injuries or nonspecific reperfusion-related mucosal changes. In addition, the study lacked a comparator, standardized scoring system, and a reproducibility assessment. Practical issues remain unresolved, including procedural time, workflow integration, equipment availability, and the possibility of cholangioscopy-related mucosal injury.

The next step should be a prospective translational study correlating predefined cholangioscopic findings with biliary viability markers, histopathology, and posttransplant biliary complications. Such a validation will determine whether this promising proof-of-concept technique can become a clinically actionable tool.