Tri-Scenario-Based MAICOHAN Strategy for Minimally Invasive Extended Left Hepatectomy

Minimally invasive extended left hepatectomy (MI-ExLH) remains a technically challenging procedure that is not yet standardized.

We retrospectively reviewed cases of minimally invasive left hepatectomy (MI-LH) and MI-ExLH performed between 2018 and 2025 at a single institution. Surgical strategies were classified into three categories according to the tri-scenario-based MAICOHAN strategy (MHV-based Assessment and Involvement/non-involvement in Caudate-hilum-dependent Optimal extended left Hepatectomy Algorithmic Navigation): (1) the cranio-dorsal or cranio-ventral approach, selected depending on the tumor-middle hepatic vein (MHV) relationship, (2) the Arantius-first or caudate lobe resection approach, chosen based on caudate lobe involvement, and (3) the liver-transection-first or left-hepatic-duct-dissection-first approach, based on the tumor-left hepatic hilum relationship. We divided the cases into two groups-the MAICOHAN strategy group (MS group) and the non-MAICOHAN strategy group (non-MS group), where procedures were and were not performed according to the abovementioned scenarios, respectively.

Eleven MI-LH and 12 MI-ExLH cases were included (MS group, n = 11; non-MS group, n = 12). Operative time and length of hospital stay were significantly shorter in the MS group than in the non-MS group (262 vs. 376 min, p = 0.023; 6 vs. 9 days, p = 0.016). In the subgroup analysis restricted to MI-ExLH cases, the incidence of positive surgical margins was significantly lower in the MS group (0% vs. 50%, p = 0.046).

The tri-scenario-based MAICOHAN strategy provides a practical framework that may contribute to guiding surgeons in planning and performing MI-ExLH more safely and consistently.