Hepatobiliary surgical and liver preservation techniques have evolved to the point that the reconstruction of critical hepatic vasculature can be performed with acceptable morbidity and mortality. As a result, the indications for surgery on tumor involving the hepatocaval confluence, inferior vena cava, and/or portal vessels are expanding—this is particularly true in centers that have a strong background in both hepatobiliary oncology and liver transplantation. The techniques described in this chapter are generally applicable to cases where the local aggression of the tumor involved—as it relates to vascular structures such as the cava and hepatic veins—does not preclude long-term survival. Examples of this concept include intrahepatic cholangiocarcinomas that are confined to the liver with no lymph node extension but invasion or encasement of major vascular structures in the liver, sarcomas that invade or impinge on major hepatic vascular structures, and selected cases of metastatic colon cancer or hepatocellular carcinoma. Whatever the diagnosis, careful patient selection is of paramount importance to ensure that the possible benefits outweigh the risks: these cases should always be approached in the context of multidisciplinary oncologic care.

The liver receives a dual vascular inflow of approximately 1500 ml/min. The portal vein provides three quarters of total hepatic blood flow while the hepatic artery provides the remaining 25%. This inflow is directed into the liver and subsequently the hepatic sinusoids. Outflow from the sinusoids is via the terminal hepatic venules, which subsequently coalesce into larger branches of the hepatic veins and then the major hepatic vein branches subsequently empty into the inferior vena cava.

During liver surgery, the hepatic parenchyma must be divided and measures to control the 1500 ml/min of blood flow through the liver must be used to minimize bleeding. The great majority of liver resections can be performed using standard techniques that control blood loss and minimize hepatocellular injury (see Chapter 18). Standard techniques include maintaining a low central venous pressure to minimize bleeding from small hepatic veins and meticulous ligation or control of small intrahepatic vessels while
maintaining hepatic perfusion. However, there are instances which may require varying degrees of hepatic vascular inflow and outflow control to avoid major hemorrhage. In standard liver resection, even without vascular involvement, it may be beneficial to perform pedicle clamping (Pringle’s maneuver) to reduce bleeding from the cut surface of the liver during transection. Pringle’s maneuver has been shown to be tolerated best when applied intermittently, with 15 minute clamp periods interspersed with 5 minute periods of perfusion. Alternatively a period of ischemic preconditioning of the liver using a short period of clamping followed by a more prolonged clamp application of up to one hour has been shown to attenuate ischemia reperfusion injury. There are few contraindications to using hepatic inflow occlusion, or pedicle clamping during most liver surgery. In patients that have an injured liver due to biliary obstruction, chemotherapy, or steatosis, it may be wise to avoid inflow occlusion but should be used if bleeding is excessive.

Cases that involve major vascular structures that require resection and reconstruction will need additional vascular control. If possible, the surgeon can take advantage of the dual blood supply to the liver (arterial and portal) and clamp one source while maintaining the other. For example, if only the portal vein needs to be resected and reconstructed, proximal and distal control of the vein can generally be achieved while maintaining arterial flow to the liver, thus avoiding prolonged ischemia. If hepatic arterial involvement requires resection and reconstruction portal venous flow can be maintained and hepatic ischemia is minimized.

Tumors that involve or are in close proximity to the inferior vena cava or confluence of the hepatic veins may require total vascular isolation of the liver, with control of both vascular inflow and outflow. Depending on the complexity of the vascular reconstruction that is to be performed, it may be necessary to increase the acceptable period of hepatic ischemia by using cold perfusion techniques, whether in situ, or ex vivo. Historically, complete vascular isolation has not been as well tolerated by the liver or the patient as simple inflow occlusion, and major vascular reconstruction during liver surgery has been associated with increased morbidity and mortality. Patients with any significant comorbidity, including even mild renal dysfunction are likely poor candidates for hepatic resection with vascular reconstruction. This chapter will focus on techniques involved in resecting and reconstructing the IVC and hepatic veins.