Special attention must be given to taking down the hilar plate, followed by carefully mobilizing the left hepatic duct, the left hepatic artery, and the left branch of the portal vein from the undersurface of the overlying liver. These vessels enter the liver at the base of the umbilical fissure. After the vessels and other structures are gently dissected away from the liver, an area is exposed for the incision between the medial and lateral segments of the left lobe of the liver (Figure 6). The bridge of hepatic parenchyma across the umbilical fissure does not contain a major vascular structure and can be divided with electrocautery. Branches to Segment 4 from the left portal vein can be individually controlled along the right border of the round ligament as it traverses the umbilical fissure.
The right lobe is rotated medially away from the diaphragm, exposing the small hepatic veins communicating with the inferior vena cava. These small vessels are carefully and securely ligated, followed by exposure of the major right hepatic vein (Figure 7). As in right hepatectomy, the caval ligament is carefully divided to expose the right hepatic vein.
A vessel loop is passed around the large right hepatic vein, and the liver tissue gently pushed away from this large vein to permit the application of two curved Cooley vascular clamps to the vein. Sufficient vein must extend beyond the vascular clamp to enable oversewing of the open ends after the vein has been divided. Two rows of nonabsorbable vascular sutures are used to secure the end of the right hepatic vein. The middle hepatic vein can be treated in a similar manner or its branches ligated individually as the medial and lateral segments are divided (Figure 8). The hepatic veins can similarly be controlled using a vascular stapler.
The division of the liver lobes is made nearer the falciform ligament, rather than in the line of the vascular demarcation between the right and left lobes. Deeply placed stay sutures are placed parallel a few centimeters away from the falciform ligament. These sutures are placed on either side of the incision and tied to control the bleeding, but care is taken not to crush the liver substance. The liver is divided with an ultrasound dissector or electrocautery unit between the area supplied by the middle hepatic vein and medial to the ...