Anatomic versus non-anatomic resection for intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

Background: The value of anatomic resection (AR) in intrahepatic cholangiocarcinoma (ICC) remains controversial. This study compares the perioperative safety and long-term outcomes of AR versus non-anatomic resection (NAR) in ICC patients. Methods: A systematic search was conducted in PubMed, Medline, Embase, Cochrane Library, China National Knowledge Infrastructure(CNKI) and Wanfang database for prospective or retrospective studies comparing the efficacy of AR and NAR in, ICC published to June 1, 2024. Meta-analyses were performed on surgical factors, perioperative outcomes and long-term prognosis for both the entire cohort and the propensity score-matched (PSM) cohort. The primary outcome measures were overall survival (OS) and disease-free survival (DFS). Results: Seven studies, including 1801 ICC patients, were analyzed. In both the entire and the PSM cohort , the AR group demonstrated superior OS (HR=0.71, 95% CI=0.57-0.88, P =0.002 and HR=0.70, 95% CI=0.59-0.83, P <0.0001, respectively) and DFS (HR=0.75, 95% CI=0.62-0.91, P =0.004 and HR=0.68, 95% CI=0.58-0.79, P <0.00001, respectively) compared to the NAR group. AR significantly improves 1-year, 3-year, 5-year DFS and 5-year OS(all P <0.05). In the PSM cohort, AR and NAR groups showed comparable blood loss, operative times, overall complications, and major complications (all P >0.05). Subgroup analysis revealed that among patients with tumor >5 cm, AR achieved better OS and DFS, whereas patients with tumors ≤5 cm did not experience survival benefits from AR. Conclusion: This study suggests that AR, compared to NAR, can improve OS and DFS without increasing perioperative risks, particularly in ICC patients with tumors larger than 5 cm.