2. INTRODUCTION :
The liver is the largest organ in the body, weighing 1.7
kg in the average 80-kg man.
It sits in the right upper quadrant beneath the
diaphragm, and is protected by the rib cage.
The liver parenchyma is entirely covered by a thin
capsule (Glisson’s capsule) and by visceral peritoneum
on all but the posterior surface of the liver, termed the
it is divided into a large right lobe, which constitutes
three-quarters of the liver volume, and a smaller left
3. ANATOMY OF THE LIVER :
Understanding the segmental anatomy of the liver has
greatly facilitated safe liver surgery.
Couinaud, a French surgeon, described the liver as being
divided into 8 segments. Each one of these segments can
be considered as a functional unit, with a branch of hepatic
artery, portal vein, and bile duct, and drained by a branch of
the hepatic vein.
The overall anatomy of the liver is divided into a functional
right and left portions along the line between the gall
bladder fossa and the middle hepatic vein (line of Cantlie).
Each of these major right and left portions of the liver is
divided into sectors and segments depending on the
distribution of hepatic veins and portal structures.
4. Liver segments (Il – IV) lie to the left of the line
of Cantlie, functionally, is the left liver, which is
supplied by the left branch of the hepatic
artery and the left branch of portal vein and
drains bile via the left hepatic duct.
Liver segments (V – VIII) lie to the right of the
line of Cantlie, functionally, is the right liver,
which is supplied by the right branch of the
hepatic artery and the right branch of portal
vein and drains bile via the right hepatic duct.
6. Couinaud terminology for liver
resections 1957 :
Right hepatectomy: involves segment V, VI, VII, VIII
Extended right hepatectomy (right lobectomy): involves
segment IV,V, VI, VII, VIII ± I resection.
Left hepatectomy: involves segment II, III, IV resection.
Extended left hepatectomy: involves segment II, III, IV, V,
VIII ± I resection.
Left lobectomy (left lateral segmentectomy): involves
segment II & III resection.