**3. Types of liver surgery and indications**

#### **3.1 Liver surgical procedures**

There are important surgical principles and prerequisites that are mandatory when planning any liver operation. These are relevant for open, laparoscopic and robotic surgery. Most surgical procedures performed upon the liver involve the removal or resection of defined portion(s) of the liver. At the end of liver surgery there must be an adequate volume of liver of suitable quality left in-situ—termed future liver remnant (FLR)—that is generally considered to be 30% of original liver volume. In addition the FLR must have arterial and portal inflow, venous outflow and biliary drainage.

The different types of hepatectomies are illustrated in **Figure 2**. As discussed above as each segment of the liver has its own arterial and venous blood supply,

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**Figure 2.**

*as non-anatomical resections.*

*Robotic Liver Surgery*

operations.

*DOI: http://dx.doi.org/10.5772/intechopen.87995*

**3.2 Indications for liver surgery**

referred to as non-anatomical resections (NARs).

biliary drainage and venous outflow, a single segment of the liver can be resected without significant risk to the patient (see below). Specifically resections that follow defined anatomical planes are referred to as anatomical resections (e.g. left hepatectomy or segment 7 resection) and those crossing anatomical planes are

These liver procedures have traditionally been performed as open surgical opera-

Most liver operations are performed for the management of both benign and malignant hepatic tumours. **Table 1** demonstrates the frequency of these liver

The vast majority of liver operations performed for metastatic liver disease are for colorectal liver metastasis, approximately 80% of all liver operations are performed for liver cancer. Other metastatic diseases considered for liver resection include neuroendocrine tumours and sarcoma. The most common primary malignant tumour of the liver is the hepatocellular carcinoma (HCC) and in patients with preserved liver function, hepatectomy can be considered. Importantly in patients were the liver is damaged or cirrhotic, liver surgery cannot be undertaken, as the liver will not regenerate. Cholangiocarcinoma is the other common primary liver tumour and in cases where there is no metastatic/extrahepatic disease hepatectomy as listed in **Figure 2** can be considered. Benign tumours include hepatocellular adenoma, hepatic haemangioma and focal nodular hyperplasia can be considered for liver resection in selected patients particularly if symptomatic. Hepatectomy may also be the procedure of choice to treat intrahepatic gallstones or parasitic

*The different types of hepatectomy. Liver resections are classified based upon the segments of the liver that are resected. A right hepatectomy/lobectomy is surgical resection of segments 5, 6, 7 and 8 whereas a left hepatectomy/lobectomy constitutes resection of segments 2, 3, 4. An extended left hepatectomy involves the further resection of segments 5 and 8. Combining a resection of segment 4 with a right hepatectomy is a classified as an extended right hepatectomy. Resection of a named segment is termed a segmentectomy and two contiguous segments a bi-segmentectomy. Resections crossing anatomical planes irrelevant of size are classified* 

tions but during the late 1990s there was a drive to perform these operations via minimally invasive techniques such a laparoscopic surgery and more recently via robotic-assisted surgery. These surgical approaches are discussed is more detail below.

#### *Robotic Liver Surgery DOI: http://dx.doi.org/10.5772/intechopen.87995*

*Liver Disease and Surgery*

**Figure 1.**

(segments 2 and 3) and a left medial section or segment 4. The right hemi-liver can be divided into the right anterior section (segment 5 and 8) and right posterior section (segment 6 and 7). This segmental liver anatomy was originally described by Couinaud and is based upon the eight major divisions of the hepatic artery, portal vein and the biliary system (**Figure 1**). Segment 1 or caudate lobe is a unique liver lobe and is discussed below. Each Couinaud segment has its own arterial and portal

*The segmental anatomy of the liver. The liver derives its blood supply from the hepatic artery and portal vein. Both divide these structures divide into a left and right vessel to supply the respective side of the liver. The hepatic artery and portal veins divide into segmental branches to supply each of the segments within the liver. Correspondingly each segment has its own biliary duct and venous drainage. Importantly segment 1/caudate lobe is a specialised lobe of the liver and receives blood supply from both the left and right hepatic arteries with biliary drainage to both the left and right biliary ducts. Hence the left liver is made up of the segments 2, 3 and* 

Blood enters the liver from two separate sources. Twenty percent of total liver blood flow is derived from the hepatic artery that is a branch of the coeliac artery. The remaining 80% is derived from the portal vein that is formed by the union of the Superior Mesenteric Vein and Splenic Vein behind the head of the pancreas. This venous blood brings nutrients and oxygen to liver parenchymal cells (e.g. hepatocytes, sinusoidal endothelial cells and cholangiocytes). Venous outflow of the liver is via the hepatic veins, which drain directly into the IVC and then the heart. This basic structure of the liver is integral to the planning of and performance of liver surgery.

There are important surgical principles and prerequisites that are mandatory when planning any liver operation. These are relevant for open, laparoscopic and robotic surgery. Most surgical procedures performed upon the liver involve the removal or resection of defined portion(s) of the liver. At the end of liver surgery there must be an adequate volume of liver of suitable quality left in-situ—termed future liver remnant (FLR)—that is generally considered to be 30% of original liver volume. In addition the FLR must have arterial and portal inflow, venous outflow

The different types of hepatectomies are illustrated in **Figure 2**. As discussed above as each segment of the liver has its own arterial and venous blood supply,

blood supply, venous outflow and biliary drainage.

*4 and the right liver of segments 5, 6, 7 and 8.*

**3. Types of liver surgery and indications**

**3.1 Liver surgical procedures**

and biliary drainage.

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biliary drainage and venous outflow, a single segment of the liver can be resected without significant risk to the patient (see below). Specifically resections that follow defined anatomical planes are referred to as anatomical resections (e.g. left hepatectomy or segment 7 resection) and those crossing anatomical planes are referred to as non-anatomical resections (NARs).

These liver procedures have traditionally been performed as open surgical operations but during the late 1990s there was a drive to perform these operations via minimally invasive techniques such a laparoscopic surgery and more recently via robotic-assisted surgery. These surgical approaches are discussed is more detail below.
