Endoscopic treatment and outcome-oriented classification of biliary strictures after liver transplantation: a multicenter retrospective cohort study.

Background: To date, there is no consensus classification of post-liver transplantation biliary strictures (LTBS), particularly for guiding treatment. This study aimed to propose a novel classification system for guiding treatment choice and prognosis prediction. Methods: Patients with biliary stricture (BS) from three centers were analyzed retrospectively. Combined with the latest guidelines, a location-based classification system was developed that included the following categories: extrahepatic BS (type I), perihilar BS (type II), and intrahepatic BS (type III). Stent treatment choices were assessed, and a fully covered self-expandable metal stent (FCMS) with plastic biliary stent (PBS) implantation method for type II was introduced. Treatment characteristics and outcomes among the three types were also analyzed. Results: According to initial successful endoscopic cholangiography, 96 patients were classified into three types: I (43.8%), II (32.3%) and III (24.0%). For type I patients, fewer treatment sessions (P=0.02) and lower costs (P=0.04) were noted for FCMS compared to PBS. Compared to PBS implantation alone, FCMS + PBS had a similar advantage as the type II group. During the follow-up period, 69.0% of type I, 61.3% of type II and 34.7% of type III patients achieved stent-free success, and type III patients demonstrated the worst treatment effects (P=0.03). The stent duration, number of endoscopic procedures increased from type I to type III patients (P=0.04). Conclusions: This location-based classification provides insights for clinical treatment recommendations, offering a typological basis for establishing a standardized treatment protocol for BS after liver transplantation.