The single biggest preoperative factor to account for when considering patients for major anatomic liver resection, including left hepatic lobectomy, is the health of the native background liver.

In a patient with a healthy background liver, anatomic trisegmentectomy can be performed and tolerated; however, in patients with chronic liver disease of any kind, the extent of resection needs to be carefully weighed against the possibility of postoperative liver insufficiency and/or failure.

Among others, historical factors that may indicate the presence of underlying chronic liver disease include accurate quantification of alcohol use (current and past); identification of risk factors for viral hepatitis exposure (intravenous [IV] drug abuse, tattoos, promiscuous sexual behavior, history of blood transfusions); comorbidities that predispose to nonalcoholic fatty liver disease (NALFD) such as hypertension, hyperlipidemia, diabetes, and high cholesterol; prior chemotherapy exposure(s) in cases of patients who are being considered for liver resection for oncologic purposes, the type and duration of which can predispose to chemotherapy-associated steatohepatitis (CASH); and past history suggestive of liver decompensation including prior episodes of jaundice, gastrointestinal (GI) bleeding, ascites production, and so forth.

Findings on physical examination of the stigmata of cirrhosis are indicative of advanced chronic liver disease and are generally considered as contraindications for major liver resection (Table 1).

Standard blood work including a complete blood count, complete metabolic panel, and coagulation panel are required prior to proceeding with any major liver surgery.
When the history and/or physical examination points to a chronic, underlying liver disease, additional serologic testing for any of the viral hepatitides as well as other obscure causes of cirrhosis (hemochromatosis, Wilson’s disease, etc.) may be advisable. In cases of liver tumors, carcinoembryonic antigen (CEA), α-fetoprotein (AFP), and/or carbohydrate antigen 19-9 (CA19-9) levels occasionally can provide diagnostic clarity and therefore should routinely be obtained.

Ultrasonography can identify cirrhotic liver morphology by providing information on the size, contour, and echotexture of the liver. While this modality has the advantage of being noninvasive, it is also highly operator dependent.

When planning major liver surgery, high-quality crosssectional imaging is a prerequisite. Either computed tomography (CT) or magnetic resonance imaging (MRI) can be used. Contrast enhancement, which should include both an early hepatic arterial phase as well as a delayed portal venous phase (so-called liver protocol scan), is the best manner in which to obtain detailed images of the liver as well as the relationship of tumor(s) to the major intra- and extrahepatic structures.

Additionally, liver protocol scans can, in some instances, obviate the need for invasive biopsy and the risks associated therein due to the fact that certain liver tumors including simple cysts, hemangioma, focal nodular hyperplasia, and hepatocellular carcinoma have radiographic appearances that can be diagnostic in the appropriate clinical setting.

MRI/magnetic resonance cholangiopancreatography (MRCP) may be preferred in cases in which bile duct resection/reconstruction is a possibility, as this modality provides superior anatomic definition of the biliary anatomy in comparison to CT scan alone.

Specifically, in regard to left hepatic lobectomy, careful attention should be paid to the relationship of any tumor(s) within the left lobe to the left hilar structures as well as the left hepatic vein and/or common trunk (FIG 3A). Welldescribed anatomic variants, such as a replaced or accessory left hepatic artery (FIG 3B) or a right posterior hepatic duct arising from the main left hepatic duct (FIG 3C), should be carefully evaluated for as their presence may alter the conduct of the operation.