Extent of liver resection for incidental gallbladder cancer: Anatomic versus nonanatomic approaches in T2-T3 disease

Incidental gallbladder cancer (IGBC) is increasingly diagnosed after cholecystectomy performed for presumed benign disease. For T2 and selected T3 tumors, completion radical re-resection with liver resection and regional lymphadenectomy is recommended, but the optimal hepatic extent-nonanatomic wedge resection versus anatomic segment IVb/V resection-remains debated.

This narrative review summarizes evidence from IGBC-specific series and registries, international multicenter cohorts, meta-analyses, and contemporary consensus guidelines comparing wedge resection and segment IVb/V resection for T2-T3 gallbladder cancer, with emphasis on oncologic outcomes, perioperative morbidity, and the evolving role of systemic therapy.

Across contemporary cohort studies and meta-analyses, margin-negative wedge resection appears to provide long-term oncologic outcomes comparable to segment IVb/V resection for T2 disease, while segment IVb/V is consistently associated with higher perioperative morbidity. Tumor location (T2a vs T2b) may correlate with prognosis, but does not independently mandate greater liver volume when nodal and margin status are considered. In IGBC, outcomes are driven primarily by nodal involvement, residual disease, and margin status rather than by the specific hepatic volume removed. For T3 and other high-risk presentations, large international datasets suggest limited incremental benefit from escalation to major hepatectomy or routine extrahepatic bile duct resection, although bile duct resection is indicated when the cystic duct margin is positive. Neoadjuvant systemic therapy is increasingly considered in selected borderline-resectable or node-positive disease to enable biologic selection and improve the likelihood of achieving an R0 resection with limited hepatic excision.

For T2 IGBC, a parenchyma-sparing, margin-negative wedge resection of the gallbladder bed combined with high-quality regional lymphadenectomy appears to provide oncologic outcomes comparable to segment IVb/V resection in most patients. Current evidence does not demonstrate a consistent survival advantage for routine segment IVb/V resection. In T3 and high-risk disease, surgical strategy should prioritize biologic selection and integration of systemic therapy, with hepatic extent tailored to margin requirements rather than routine escalation.