Anatomic Versus Non-anatomic Liver Resection for Intrahepatic Cholangiocarcinoma: A Systematic Review and Patient-Level Meta-Analysis

Background. The current standard treatment for intrahepatic cholangiocarcinoma (ICC) involves complete liver resection with negative surgical margins and lymphadenectomy, followed by adjuvant chemotherapy. Debate is ongoing regarding the necessity of systematic anatomic resection (AR). This study aimed to summarize existing literature to determine whether AR leads to better oncologic outcomes than non-AR for patients with resectable ICC. Methods. A systematic literature review (PubMed, Embase, and Google Scholar) was performed until December 2023. Only studies comparing the oncologic outcomes of AR and non-AR for ICC using propensity score matching or inverse probability of treatment weighting were considered. A meta-analysis of aggregated data for perioperative variables and a reconstructed patient-level meta-analysis for survival data were performed. Results. Five articles were gathered (n = 930 patients after matching: 465 AR/465 non-AR patients). The overall survival (OS) rates were higher in the AR group than in the non-AR group at 1, 3, and 5 years (71.5%, 46.1% and 34.3% vs. 63.6%, 32.9%, and 24.8%, respectively; hazard ratio [HR] 0.74; 95% CI 0.63-0.87; P < 0.001). The same results were observed for the disease-free survival (DFS) rates (58.3%, 33.4%, and 24.5% for AR vs. 45.6%, 23.1%, and 17.4% for non-AR; HR 0.74; 95% CI 0.63-0.86; P < 0.001). The results were confirmed in the two-stage meta-analysis for OS (HR 0.73; P < 0.001) and DFS (HR 0.73; P < 0.001). No differences were observed between the two approaches in terms of operative time, intraoperative blood loss, overall and major morbidity, and hospital length of stay. Conclusions. By pooling the available evidence, the current study demonstrated that AR for ICC patients is associated with better OS and DFS without any negative impact on postoperative outcomes.