Neoplastic Lesions

The key to successful hepatic resection of malignant disease is careful patient selection. In general:

• A primary liver tumour may be considered for resection if it involves a single lobe and there is no invasion of the portal vein or inferior vena cava. There should be little evidence of cirrhosis in the surrounding liver.

• A solitary metastatic deposit (the vast majority of which will be from a primary colorectal carcinoma) localised to a single lobe may be considered for resection. There should be no evidence of metastatic spread elsewhere and the primary tumour should have been adequately excised.

Obviously, the background physiological state of the patient has to be taken into account before surgery is considered, i.e., resection is only justified in relatively young and medically fit individuals.

As was stated above the liver is divided into right and left "surgical lobes" which are different to the anatomical lobes. The surgical lobes are separated along a plane which extends from the gall bladder bed to the inferior vena cava - the main portal plane. The surgical lobes are then subdivided into eight segments - each segment is supplied by its own portal venous and hepatic arterial pedicle (Figure 9.2).

Surgical Lobes Right Left

Figure 9.2. (a) Surgical lobes of the liver. The surgical lobes of the liver compared with the usual anatomical division into left and right lobes by the falciform ligament. (b) Segments of the liver (after Couinard). IVC = inferior vena cava, RHV = right hepatic vein, LHV = left hepatic vein, MHV = middle hepatic vein, LT = ligamentum teres. Reproduced from Mann CV, Russell RCG, Williams, NS (eds.) Bailey & Love's short practice of surgery, 22nd edition. Chapman and Hall: London, 1995.

Figure 9.2. (a) Surgical lobes of the liver. The surgical lobes of the liver compared with the usual anatomical division into left and right lobes by the falciform ligament. (b) Segments of the liver (after Couinard). IVC = inferior vena cava, RHV = right hepatic vein, LHV = left hepatic vein, MHV = middle hepatic vein, LT = ligamentum teres. Reproduced from Mann CV, Russell RCG, Williams, NS (eds.) Bailey & Love's short practice of surgery, 22nd edition. Chapman and Hall: London, 1995.

Major Liver Resection

An S-shaped right subcostal incision is used in all cases and once the abdomen is opened an initial laparotomy examination is done to ensure no other metastatic deposits are present. The definitive type of resection will depend on the site and extent of the tumour.

• Right hepatectomy - in this, the right surgical lobe is resected by transecting the liver through the main portal plane (main portal scissura). The cut surface of the residual liver is sprayed with thrombin glue to reduce postoperative blood loss and especially bile leakage.

• Left hepatectomy - this usually involves resection of the anatomical left lobe, the quadrate and caudate lobes (i.e., the left surgical lobe, although the caudate lobe may be left in situ). Again, the line of resection is the main portal plane.

• Left lobectomy - in this, the anatomical left lobe is resected by dividing the liver just to the left of the falciform ligament.

• Extended right hepatectomy - this involves the resection of the anatomical right lobe, i.e., the surgical right lobe plus the caudate and quadrate lobes. Again, the line of resection is just to the left of the falciform ligament

• Extended left hepatectomy - this is essentially a left hepatectomy which has been extended to also resect segments I, V and VIII.

As well as neoplastic conditions, major liver resection may also be used for other conditions such as trauma.

Segmental Liver Resection

Although major hepatic resection may be employed for large tumours, when a small tumour (either primary or secondary) occupies one or two segments, a segmental resection can be carried out. This removes a segment(s) of liver, which is supplied by its own vascular pedicle, and is therefore an anatomically based procedure. Whatever the segment to be resected, its vascular anatomy is delineated by intraoperative USS before dissection.

Segmental resection has several advantages over major resection; namely, as much functioning parenchyma is left as possible and the vascular supply to this is less likely to be compromised, there is reduced blood loss and the procedure is less likely to leave residual tumour.

If a metastatic deposit is single, small and superficial, a simple wedge resection using diathermy can be employed. This procedure may be performed during resection of the primary tumour, e.g., colorectal carcinoma, and sent for frozen section.

It is known that most metastatic tumours reach the liver by the portal circulation. However, the deposit itself gains its blood supply almost exclusively from hepatic arterial flow. Therefore, in inoperable metastatic disease, numerous techniques have been used to deliver chemotherapy directly into the hepatic arterial circulation:

• Infusion therapy - a catheter is passed percutaneously via the femoral artery.

• Implantable device - this can be placed at laparotomy and allows long-term infusion. An example of this technique is by using a portacath, which employs a self-sealing port which is placed subcutaneously and drugs can be injected into this at regular intervals. A catheter runs from the port to the hepatic artery.

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