Figure 14.2 shows a case of a patient who underwent extended right hepatectomy with excision of the middle hepatic vein for the tumor located in the segment VIII. Our previous criteria for reconstruction of the hepatic vein are described elsewhere [12]. Briefly, the stump of the hepatic vein in the veno-occlusive regions is reconstructed, when the remnant liver volume without venous congestion is less than 40 % of the total liver volume (TLV) for the patient with normal liver function. In this case, volume-analyzing software based on three-dimensional CT estimated the regional liver volume as non-veno-occlusive regions drained by the left hepatic vein (314 mL, 36.9 % of TLV) and veno-occlusive regions drained by the tributary of the middle hepatic vein (77 mL, 9.1 % of TLV) (Fig. 14.2a). In order to determine the need/lack for venous reconstruction, we applied fluorescence imaging technique for evaluation of veno-occlusive regions, after which the regions with decreased portal uptake were identified (Fig. 14.2b). The estimated concentration of ICG introduced in this region was 1.6 μg/mL and corresponded to 30.8 % of that in non-veno-occlusive regions (5.2 μg/mL). The functional remnant liver volume in this case was estimated as 337 mL (40 % of TLV) based on the formula: (functional remnant liver volume) = (liver volume without venous occlusion) + (liver volume with venous occlusion) × (the ratio of the concentration of ICG in the veno-occlusive regions to that in the non-veno-occlusive regions) [2]. Based on the information above, extended right hepatectomy was performed and the stump of the tributary of the middle hepatic vein was not reconstructed. The patient was discharged postoperative day 17 without presenting hepatic dysfunction.