Abstract:Radical resection remains the cornerstone of long-term survival in biliary tract cancers (BTC). However, obstructive jaundice, cholangitis, impaired hepatic reserve, and treatment-related liver injury concentrate perioperative risks along a "cholestasis-infection-functional failure" cascade, and minimally invasive access alone cannot offset these functional costs. Based on current guidelines and emerging evidence, we propose a multistage care pathway centered on the concept of functional resectability, encompassing conversion/neoadjuvant therapy, preoperative functional reassessment, function-oriented surgery, and postoperative rehabilitation with long-term follow-up. Preoperative decision-making is anchored to combined "volume-plus-function" evaluation of the future liver remnant. When necessary, regional liver function is quantified using 99mTc-mebrofenin SPECT/CT and indocyanine green clearance testing, while selective biliary drainage, infection control, nutritional and coagulation optimization, and portal vein embolization are applied to establish a functional safety window. Intraoperatively, indocyanine green fluorescence imaging, intraoperative ultrasound, and three-dimensional planning are integrated to facilitate R0 resection and optimize reconstruction. Postoperatively, ERAS-based management is adopted, and key endpoints-including post-hepatectomy liver failure, clinically relevant postoperative pancreatic fistula, and patient-reported outcomes-are used to evaluate treatment benefit. This pathway emphasizes a "function-first, minimally invasive second" strategy, forming a closed loop of dynamic assessment, proactive intervention, and outcome measurement to maximize functional preservation and quality of life while maintaining oncological radicality.