Page 196 - Medicine and Surgery
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192 Chapter 5: Hepatic, biliary and pancreatic systems
T-tube is sited into the opening, which is brought out
Inferior vena cava
to the abdominal wall. The T-tube allows drainage of
Right lobe Left lobe bile and also allows a cholangiogram later. Alternatively,
common bile duct stones are removed at endoscopic ret-
rograde cholangiopancreatography (ERCP).
Laparoscopic cholecystectomy requires three or four
cannulae inserted through the anterior abdominal wall,
Caudate and for visualisation and access with operative instruments.
quadrate lobes
(functionally part The cystic duct and artery are clipped and dissected,
of left hemi-liver) while the gallbladder is held retracted.
Open cholecystecomy often requires quite a long stay
Gallbladder Hepatic artery and in hospital, possibly a week or more, whereas laparo-
portal vein scopic cholecystectomy may be conducted as a day case.
Complications include haemorrhage, respiratory
Figure 5.3 Anatomy of the liver. problems and wound infection. Bile leakage and haem-
orrhage may require further surgery. Laparoscopic tech-
This means that right hepatectomy, left hepatectomy nique reduces the incidence of respiratory problems and
and extended right hepatectomy (right lobe plus cau- surgical site infection.
date and quadrate lobes) or individual segments may be
resected. The liver is first mobilised from its peritoneal
attachments. The appropriate vessels for the segment(s) Disorders of the liver
are ligated and divided before the segment(s) are dis-
sectedawayfromtheremainderoftheliver.Carefuliden- Introduction to the liver and
tification and ligation of biliary ducts and smaller vessels liver disease
is required to reduce blood loss and therefore morbidity
and mortality. Drainage is required postoperatively, to Introduction to the liver
prevent bile from pooling intra-abdominally.
The liver is divided into two lobes, left and right (which
includes the caudate). It has two blood supplies: 25% of
Cholecystectomy
its blood originates from the hepatic artery (oxygenated)
Surgical removal of the gallbladder and associated stones and 75% originates from the portal vein that drains the
in the biliary tract may be by open surgery or laparo- gastrointestinal tract and spleen. This blood is therefore
scopic surgery. relatively low in oxygen, but rich in glucose, lipids and
Cholecystectomy may be indicated for symptomatic amino acids.
gallstones. Cholecystectomy is also considered in The functions of the liver are carried out by the hepa-
younger patients with asymptomatic gallstones in or- tocytes, which have a special architectural arrangement.
der to prevent complications such as acute pancreatitis. Blood enters the liver through the portal tracts, which
Carcinoma of the gallbladder is treated by wider resec- contain the triad of hepatic artery, portal vein and bile
tion, including neighbouring segments of the liver and duct. It then filters from the edges of the lobule to the
regional lymph nodes. central (efferent) vein. The lobule is classically used to
Open cholecystectomy is usually performed through describe the histology of the liver (see Fig. 5.4a) but the
aright subcostal (Kocher) incision or by a paramedian acinus forms the functional unit (see Fig. 5.4b).
or midline incision. Cholangiography may be used to The hepatocytes in zone 1 of the acinus receive well-
visualise the duct system. The gallbladder is removed oxygenated blood from the portal triads, whereas the
with ligation and division of the cystic duct and artery. hepatocytes in zone 3 receive poorly-oxygenated blood
If stones have been found, the common bile duct may and are therefore more vulnerable to damage when the
be opened longitudinally and the stones removed. A blood supply is compromised.