Samuel K. S. So

Description: Liver resections usually are performed to remove primary tumors or metastatic tumors to the liver. The most common malignant primary liver tumor is hepatocellular carcinoma (HCC), usually caused by chronic hepatitis B or C, and cirrhosis due to chronic alcohol abuse. Liver resection is also performed for an enlarging hepatic adenoma, which is a benign primary tumor that is susceptible to rupture. The most common secondary tumors removed are metastases from colorectal cancer. In rare cases, it may be necessary to resect a devitalized area of the liver following trauma. The mortality and morbidity following liver resection depends on the extent of the surgery, experience of the surgeon, and the patient’s hepatic function. In general, the risk of resection is higher in patients with primary HCC where the uninvolved part of the liver frequently is cirrhotic or diseased from chronic hepatitis B or C. Cirrhotic patients with Plt counts < 80,000, portal HTN with varices, ascites, albumin < 3.5 g/L, and prolonged INR are generally unsuitable candidates for major liver resection because of the high risk of postop liver failure.

Intraop blood loss is the most important predictor of short-term survival. Bleeding is largely from intrahepatic branches of portal and hepatic veins injured during the dissection, potentially leading to massive blood loss within minutes. Liver resection performed by experienced liver surgeon using modern dissection tools often can be performed successfully without the need for blood transfusions (cell salvage techniques should not be used when operating on cancer patients). The mortality rate of major liver resection should be < 2-5%. In my experience, most patients do not require postop ICU care and are usually discharged within 4-5 d. Improved outcomes result from better surgical exposure and mobilization of the liver combined with the standard adoption of new dissection tools to minimize blood loss. These include new ablation devices to coagulate along the planned line of a resection (such as InLine) combined with the use of dissectors using high-pressure water jet (Hydrojet) or ultrasonic pulses (CUSA) to expose the intrahepatic vessels and bile ducts. Intraop ultrasound is very helpful for two reasons: (1) in planning the line of resection and mapping out its relationship with the large intrahepatic portal and hepatic veins and (2) in surveying the entire liver to look for multifocal lesions.

Anatomic vs. nonanatomic liver resection: Until the last decade, most liver surgeons performed anatomic liver resections in which the porta hepatitis is dissected and the corresponding extrahepatic branches of the hepatic artery, portal vein, bile duct, and hepatic vein are mobilized and ligated before resection of the liver parenchyma (Fig. 7.5-1). In nonanatomic liver resections, only the tumor with a margin of 1-2 cm is removed instead of the entire anatomic lobe or segment. This approach is particularly appropriate in patients with cirrhosis or chronic hepatitis, in whom removing too much of the liver will predispose them to hepatic decompensation, and in patients with liver metastases where the risk of recurrence remains high. When nonanatomic resection is performed, dissection of the porta hepatis is unnecessary. Instead, branches of the vessels and hepatic ducts are ligated and resected as they are encountered during the resection of the liver parenchyma. All patients undergoing liver resection should also be grounded with the appropriate pads prior to draping for possible radiofrequency ablation of lesions found not to be suitable for resection.

Temporary occlusion of the hepaticoduodenal ligament that contains the main portal vein, hepatic artery, and common bile duct (Pringle maneuver) can be used in resection to minimize blood loss. Most patients will tolerate this maneuver for 15-20 min. In some patients, it may be necessary to repeat the maneuver twice to complete a major resection. However, with good surgical exposure and standard adoption of new dissection tools to minimize blood loss, the Pringle maneuver is rarely necessary.

Usual preop diagnosis: Benign and malignant primary or metastatic tumors of the liver