When the main trunk of the portal vein or its first-order branch seems to abut the tumor, a hemi-hepatectomy, i.e., a right or left hepatectomy, should be considered, and the combined resection of the wall of the main portal vein may be required. In such cases, the combined resection and the following choledocho-jejunostomy may be also required, although much less frequently, and the indication should be limited from the oncological standpoint [5]. Indeed, the management of the portal vein, hepatic artery, and bile duct when a CLM tumor is located near the hepatic hilum, is almost the same as that in hilar bile duct carcinoma. When the tumor does not invade the whole circumference of the portal vein, a wedge resection of the wall is suitable (Fig. 17.2a). A primary closure may be enough to secure intrahepatic portal flow for a small defect of the venous wall (Fig. 17.2b); otherwise a patch repair is indicated (Figs. 17.2c and 17.3). The suture direction in a primary closure should be vertical, rather than longitudinal, to the portal axis in order to prevent stenosis of the portal vein (Fig. 17.2b). When the tumor invades the whole circumference or the area in contact with the tumor is relatively large, a segmental resection of the portal vein followed by either direct end-to-end anastomosis or interposed reconstruction using a tubular graft may be indicated (Fig. 17.2d). Compared with the caval flow, portal flow is more sensitive to the area of the anastomotic lumen, and meticulous care should be devoted to prevent stenosis during the suture. For example, the suturing thread should be pulled gently, and some surgeons prefer to make so-called “growth factor” finishing anastomosis (Fig. 17.2e).

When a CLM tumor is located near the hepatic hilum, as in hilar bile duct carcinoma, the reconstruction of the hepatic artery as well as portal vein is sometimes required. It is usually accompanied with hemi-hepatectomy, and the hepatic arterial reconstruction is required when a tumor invades the hepatic arterial branch feeding the hepatic remnant. Radical surgery is contra-indicated when the hepatic artery which is subject to reconstruction cannot be encircled at the distal side of the tumor, which should first be confirmed after the laparotomy. Arterial reconstruction may be performed in direct end-to-end anastomosis between the stumps of the hepatic arteries; otherwise, an arterial pedicle graft must be prepared using, for example, the right gastroepiploic artery, the gastroduodenal artery, the middle colic artery, and the left gastric artery.