Biliary Drainage and Complex Hepatobiliary Surgery in Biliary Tract Cancers: A Framework for Selective Centralization

Background/Objectives: Biliary tract cancers (BTCs) are rare, heterogeneous malignancies that frequently present with biliary obstruction and require complex multidisciplinary care. Decisions regarding biliary drainage, future liver remnant (FLR) optimization, and major hepatobiliary surgery may influence perioperative risk and treatment eligibility. This narrative review evaluates the evidence supporting selective centralization and proposes a network-based framework that considers tumor subtype, procedural complexity, and access to care. Methods: The scope and principal topics were defined during the multidisciplinary COST Training School “Biliary Tract Cancers: Practical Approaches in Challenging Environments”, held in Barcelona, Spain, on 20–21 March 2026. Members of the author group conducted topic-specific PubMed/MEDLINE searches within their areas of expertise. Guidelines, systematic reviews, meta-analyses, and relevant clinical studies were synthesized narratively. BTC-specific findings were distinguished from evidence derived from mixed populations. No formal risk-of-bias assessment or consensus voting process was undertaken. Results: Preoperative biliary drainage should be selective, with the indication, target, and modality determined by clinical status, biliary anatomy, treatment intent, and planned intervention. FLR assessment should integrate volume and function, particularly in patients with cholestasis or cholangitis. Evidence supporting augmentation strategies varies by technique and population. Observational studies associate higher procedural volumes with favorable outcomes, although patient selection and case-mix differences limit causal interpretation. Tumor-specific pathways distinguish perihilar, intrahepatic, and distal cholangiocarcinoma and gallbladder cancer. The proposed network combines expert-center coordination of complex interventions with regional care supported by shared protocols, defined responsibilities, escalation pathways, and outcome monitoring. Conclusions: Selective centralization offers an organizational approach to balancing specialist expertise with timely and equitable access. Prospective multicenter evaluation is needed to assess safety, treatment delays, access to curative therapy, patient-centered outcomes, and resource use before wider clinical or policy adoption.