There are a number of indications for removal of all or part of the left lobe of the liver. The most common indication is evidence of one or more metastases from a previously resected colorectal cancer. The diagnosis is supported by a rising carcinoembryonic antigen (CEA) level during repeated postoperative evaluations. Liver function studies are performed and evaluated. Imaging scans verify the location, size, and probable number of metastases. The initial operative notes and the pathologist's report should be carefully studied for evidence of metastasis at the time of the initial operation. Studies to identify abdominal and lung metastases, including colonoscopy, must be negative. A period of delay may be chosen to reassess the trend of the CEA levels and CT scans, as well as to evaluate the risk of a second-look procedure in an elderly patient. PET/CT to identify occult intra and extrahepatic disease should be undertaken.
An informative discussion with the patient and the family is part of the preoperative preparation. Antibiotics are given and cross-matched blood is made available. Intravenous catheters are inserted in both arms for the administration of fluids and blood products, and central venous pressure is monitored.
A general anesthetic with the minimum of potential for injuring the liver is given.
The skin is prepared over the entire abdomen and the chest since a sternotomy may be required.
Various incisions have been used, but the bilateral subcostal incision with midline extension to the xiphoid provides excellent exposure. Extra assistants may be needed, unless special self-retaining retractors are available to retract the left costal margin. Alternatively, a long midline incision that can be extended with a median sternotomy can be used.
The abdominal cavity is carefully inspected for evidence of pinpoint or large metastases in the pouch of Douglas, colon, mesentery, small bowel, omentum, or peritoneum. Any suspicious areas are excised for frozen section examination. The liver surface is inspected for evidence of metastases, followed by bimanual palpation to verify the diagnostic procedures suggesting metastasis in the left lobe of the liver. Metastases deep within the left lobe rather than superficially are best evaluated with a hand-held ultrasound probe. Metastases readily seen on the surface of the left lobe can be locally excised with a 1-cm margin. Metastases near the inferior liver margin can be removed by wedge incision.
The incision is outlined extending into the bed of the gallbladder. The left hepatic vein is the major vessel in the dome of the left lobe (Figure 1). When the tumor is located deep in the left lobe, the left lobe is mobilized by division of the falciform and coronary ligaments (Figure 2).
Since the median margin of the left lobe extends into the gallbladder bed, a cholecystectomy is performed after ligation and division of the cystic artery and cystic duct. Removal of the gallbladder improves the exposure for the identification of the major hepatic ducts and vessels to be divided and ligated (Figure 3).
The hilar plate or bridge of the liver, if present, is divided to enhance the exposure of the structures entering the left lobe. The left hepatic duct is freed up for the sufficient distance to allow passage of a right-angle clamp. The duct is doubly ligated and then divided (Figure 4). The division of the left hepatic duct exposes the underlying left hepatic artery, which usually arises from the common hepatic artery. The surgeon should seek out the presence of aberrant arterial anatomy. The most common variation is the abnormal origin of the left hepatic artery from the left gastric artery. In this case, the left hepatic artery will run through the pars condensa in the lesser omentum.
The left hepatic artery is gently freed up a short distance from its point of origin and doubly tied with 2-0 nonabsorbable sutures proximally (Figure 5). The area of the arterial bifurcation is inspected to be certain the blood supply to the right lobe is intact and then the artery is divided between the ligatures.