Surgery is performed on the liver for a variety of both benign (non cancerous) and malignant (cancerous) conditions. Liver surgery varies from removing a very small portion of the liver to removing up to around 70 – 75% of the liver. Enough liver needs to be left behind to ensure the liver is still able to perform its role. The liver is divided into a left and right half, both of which have four segments. The liver has a dual blood supply from the hepatic artery and portal vein. The liver drains via three main hepatic veins. The liver also produces and drains bile via the common hepatic duct.
The liver has many functions which include the conversion of sugar into energy, the elimination of waste products, the production of bile which helps to break down fats, the production of clotting factors and the metabolism and elimination of certain medications.
Various techniques are employed to dissect through and remove liver tissue and minimise operative risks. Liver resection can be broadly classified into the following categories:-
- Subsegmental resection – the lesion is removed with a small amount of normal liver tissue surrounding it (a ‘margin’)
- Segmental resection – a segment of the liver containing the tumour is removed to ensure an adequate margin is obtained
- Hemi-hepatectomy – One half of the liver is removed. This is normally done for larger tumours or multiple tumours in one half of the liver.
- Extended Hepatectomy – This involves removing one half of the liver and part of the liver on the opposite side. This is done when the tumour approaches the opposite side of the liver so part of the opposite side needs to be removed to ensure the whole tumour is fully excised.
Liver surgery may be performed via the open or laparoscopic (keyhole) technique. As with other abdominal operations, the benefits of laparoscopic surgery are smaller incisions, less post operative pain and a quicker return to activity. Often a larger incision is still required to remove the specimen however this can be placed lower in the abdomen and results in less post operative pain.
Liver surgery is a technically demanding operation with many potential complications. General risks include blood clots in the legs (DVT) or lungs (PE), a severe reaction to the anaesthetic and post operative pneumonia (lung infection). Post operative bleeding, wound infections & a post operative incisional hernia can also occur. Complications specific to liver surgery include a leakage of bile from the liver or liver failure although this is rare and normally only seen when large portions of the liver are being removed.