Anatomical Liver Resections Guided by 3-Dimensional Parenchymal Staining Using Fusion Indocyanine Green Fluorescence Imaging

Objective: To investigate the feasibility and efficacy of anatomical liver resection (ALR) guided by fused images comprising a macroscopic view and indocyanine green fluorescence imaging (fusion IGFI. Background: ALR is established in treating hepatocellular carcinoma or other malignancies to achieve curability and functional preservation. However, the conventional demarcation technique (CDT) marks only the organ surface and sometimes fails to execute a completely valid demarcation. Methods: Twenty-four consecutive ALRs for focal liver malignancy were studied using fusion IGFI. Indocyanine green was administered systemically after selective inflow clamping in 12 patients or by portal puncture and direct injection in 12 patients, and we compared demarcation findings between fusion IGFI and CDT. The strength of contrast between target and nontarget areas was quantitatively calculated as contrast index and compared between IGFI and CDT according to injection technique or state of the liver surface. Results: Fusion IGFI achieved valid demarcation in 23 of 24 patients (95.8%), whereas CDT achieved valid demarcation in only 10 patients (41.7%) (P < 0.0001). The contrast index of fusion IGFI was 0.81 (0.18-2.51), which was significantly higher than that of CDT at 0.12 (0.01-0.42) (P < 0.0001), and the same result was obtained regardless of the injection method or liver surface state used. ALR was conducted referring to 3-dimensional staining of target parenchyma, with no related perioperative adverse events. Conclusions: Fusion IGFI is a safe imaging technique for ALR that attained valid 3-dimensional parenchymal demarcation with better feasibility and clearer demarcation than CDT.