The liver is an organ which is richly vascularized and has a double blood supply. Arterial blood originates from the hepatic artery and venous blood from the large portal vein which drains blood from the bowels. The liver blood is drained via the three hepatic veins into the vena cava close to the right atrium of the heart. It is therefore important to know the course of these vascular structures when surgically dissecting the liver. The remaining liver tissue must have an intact venous outlet. The choice of operation method is decided after accurate assessment of the tumor's size and relation to these large blood vessels.
A liver resection can either be performed by a traditional open resection or by laparoscopy. Both methods allow for both wide, formal resections following anatomical structures such as blood vessels and biliary ducts, as well as smaller local (tissue-sparing) resections where the procedure is limited to removing the tumor with a minimum of surrounding healthy liver tissue.
At Oslo University Hospital, Rikshospitalet, most of the large resection procedures are performed as open surgery. This always applies when involvement of blood vessels requires vessel reconstruction. Laparoscopic surgery is recommended in most local resections, including lateral left-sided resection (segment 2/3) and in selected cases of wider, formal resections. Previous liver resections are not a contraindication for laparoscopic surgery.
Depending on the size of the liver and quality of the surrounding tissue, up to 80% of the liver can be resected. Regeneration of the liver occurs after a few months.
The liver is divided into 8 segments. The left lobe of the liver includes segments 2-4 while the right lobe includes segments 5-8. Segment 1 (caudate) overlies the inferior vena cava. The division between the two lobes is defined by the separation of the portal vein into the right and left portal veins. The falciform ligament defines the separation between left liver lobe segment 4 and segment 2/3.
A formal resection (anatomical resection/segmentectomy/lobectomy) is performed according to the liver's vascular and biliary anatomy. The traditional resections are defined as follows:
- Lateral left-sided resection: Removal of segment 2 and 3 (Resection of about 20% of the liver's volume)
- Formal left-sided resection: Removal of segment 2-4. (about 40% resection)
- Formal right-sided resection: segment 5-8 including the gallbladder are removed (about 60%)
- Extended right-sided resection: segment 5-8 plus all or parts of segment 4 are removed (up to 80% is removed, often after pre-treatment with portal vein embolization)
The tumor is removed with a margin of around 1 cm (local, non-anatomical resection/wedge resection). This may be difficult when the tumor is located close to large vessels. This method may be applicable for multiple small metastases (multiple wedge resections).
- Primary liver cancer
- Cancer in intrahepatic biliary ducts
- Liver metastasis
- Complete removal of cancerous tissue