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Gall bladder
Dr.Dler Omer
Surgical anatomy and physiology
The gall bladder is pear-shaped, 7.5-12 cm long, with a normal capacity of about 50 ml,
but capable of considerable distension in certain pathological conditions.
The anatomical divisions are: fundus, body, neck and a narrow infundibulum.
The mucous membrane contains indentations of the mucosa that sink into the muscle
coat; these are the crypts of Luschka.
The cystic duct is about 3 cm in length but variable.
Its lumen is usually 1-3 mm in diameter.
The mucosa of the cystic duct is arranged in spiral folds known as the valves of Heister.
Its wall is surrounded by a sphincteric structure called the sphincter of Lutkins.
The cystic duct joins the common hepatic duct in its supraduodenal segment in 80% of
cases, it may extend down into the retroduodenal orretropancreatic part of the bile
duct before joining.
Occasionally the cystic duct may join the right hepatic duct or even a right hepatic
sectorial duct.
The common hepatic duct is usually less than 2.5 cm long and is formed by the union of
the right and left hepatic ducts.
The common bile duct is about 7.5 cm long and formed by the junction of the cystic and
common hepatic ducts.It is divided into four parts:
• The supraduodenal portion, about 2.5 cm long, running in the free edge of the lesser
omentum;
• The retroduodenal portion;
• The infraduodenal portion lies in a groove on the posterior surface of the pancreas;
• The intraduodenal portion passes obliquely through the wall of the second part of the
duodenum where it is surrounded by the sphincter of Oddi.It terminates by opening on
the summit of the papilla of Vater.
The arterial damage during cholecystectomy may cause ischaemia and result in
postoperative bile duct stricture.
The cystic artery, a branch of the right hepatic artery, is usually given off behind the
common hepatic duct.
Occasionally, an accessory cystic artery arises from the gastroduodenal artery.
In 15% of cases the right hepatic artery and/or the cystic artery cross in front of the
common hepatic duct and the cystic duct.
The most dangerous anomalies are where the hepatic artery takes a torturous course
on the front of the origin of the cystic duct, or the right hepatic artery is torturous and
the cystic artery short.
The tortuosity is known as the ‘caterpillar turn’ or ‘Moynihan’s hump’.This variation
is the cause of many problems during a difficult cholecystectomy with inflammation in
the region of the cystic duct. Inadvertent damage to the right hepatic artery is most
difficult to control laparoscopically.
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Lymphatics
The lymphatic vessels of the gall bladder (subserosal and submucosal) drain into the
cystic lymph node of Lund (the sentinel lymph node), which lies in the fork created by
the junction of the cystic and common hepatic ducts. Efferent vessels from this lymph
node go to the hilum of the liver, and to the coeliac lymph nodes.
The subserosal lymphatic vessels of the gall bladder also connect with the subcapsular
lymph channels of the liver, and this accounts for the frequent spread of carcinoma of
the gall bladder to the liver.
Surgical physiology
Bile, as it leaves the liver, is composed of 97% water, 1-2% bile salts, and 1% pigments,
cholesterol and fatty acids.
The liver excretes bile at a rate estimated to be approximately 40 ml/hour. The rate of
bile secretion is controlled by cholecystokinin which is released from the duodenal
mucosa. With feeding there is increased production of bile.
Functions of the gall bladder
1. Reservoir for bile. During fasting resistance to flow through the sphincter is high,
and bile excreted by the liver is diverted to the gall bladder. After feeding the
resistance to flow through the sphincter of Oddi is reduced, the gall bladder
contracts and the bile enter the duodenum. These motor responses of the biliary
tract are in part effected by the hormone cholecystokinin.
2. concentration of bile by active absorption of water, sodium chloride and
bicarbonate by the mucous membrane of the gall bladder. The hepatic bile which
enters the gall bladder becomes concentrated 5—10 times, with a corresponding
increase in the proportion of bile salts, bile pigments, cholesterol and calcium.
3. secretion of mucus — approximately 20 ml is produced per day.
With total obstruction of the cystic duct in a healthy gall bladder, a mucocele develops
on account of this function of the mucosa of the gall bladder.
Investigation of the biliary tract
Plain radiograph
radio-opaque gallstones in 10% of patients.
Rarely calcification of the gall bladder, a so-called ‘porcelain’ gall bladder
(premalignant and is an indication for cholecystectomy).
Oral cholecystography (Graham—Cole test)
Iopanoic acid BP is taken as tablets on the night before the examination. A control
radiograph is taken before the tablets are given and a series of X-rays is taken on the
following day, with further films after a fatty meal. The fatty meal stimulates gall-
bladder contraction and reveals the adequacy of gallbladder function.
This investigation has been discarded by most hospitals because of its inaccuracy
except to show diverticulae and polyps, and to assess function; adequate films depend
on the patient taking the tablets, and the tablets being absorbed, secreted by the liver
and concentrated in the gall bladder after passing into the gall bladder through an
unobstructed cystic duct. Thus, a cholecystogram which shows no concentration of
contrast can result from many causes and it not diagnostic of gallstone disease.
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Intravenous cholangiography
Intravenous cholangiography (biligram—meglumineioglycamate) permits radiological
visualisation of the bile ducts.
The drug is given intravenously and is rapidly secreted by the liver into the biliary tree.
Careful radiography with or without tomography can clearly define the ducts and the
gall bladder delineating the presence of stone disease. The contrast agent can cause
allergic reactions such that this test has been discarded in most units.
Ultrasonography
US is noninvasive and is now the standard initial imaging technique for the
investigation of the patient suspected of having a gallstone, and is also the prime
investigation for the patient presenting with jaundice.
demonstrate biliary calculi, the size of the gall bladder, the thickness of the gall-
bladder wall, the presence of inflammation around the gall bladder, the size of
the common bile duct and, occasionally, the presence of stones within the biliary
tree.
It may even show a carcinoma of the pancreas occluding the common bile duct.
Radioisotope scanning
Technetium-99m (99mTc) ~labelled derivatives of iminodiacetic acid (HIDA, PIPIDA)
are excreted in the bile and ate used to visualise the biliary tree.
In acute cholecystitis the gall bladder is not seen.
The technique is used when biliary enteric anastomoses are functioning inadequately as
it will show the extent of obstruction at the anastomosis and indicate the delay in
excretion.
Computerised tomography (CT)
CT is not a useful technique in investigating the biliary tree. Its only value is in the
investigation of patients who may have a cancer of the gall bladder or bile ducts, and in
these patients will define its extent, the presence of lymphadenopathy and the presence
of metastases.
Magnetic resonance cholangiopancreatography
MRCP is now becoming the standard technique for investigation of the biliary tree.
Contrast is not necessary and, with appropriate computing, a clear outline of the
biliary tree can be achieved with a sensitive and specific diagnosis of bile-duct stones.
This technique will replace alternative diagnostic aids as the appropriate magnets with
the specific software become more widely available.
Endoscopic retrograde cholangiopancreatography (ERCP)
The ampulla of Vater can be cannulated with the aid of a fibre-optic duodenoscope.
The bile ducts are visualized after injecting water-soluble contrast. Bile can be sent for
cytological and microbiological examination, and brushings can be taken from
strictures for cytological studies.
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Acute cholangitis may follow ERCP when contrast fills a dilated and obstructed duct;
antibiotics are given as prophylaxis, and if obstruction is encountered relief of that
obstruction by the placement of a stent must be undertaken. If drainage cannot be
achieved then percutaneous transhepatic drainage should be performed.
Diagnostic ERCP is now less commonly performed, but its value is its ability to remove
stones and stent strictures, thus becoming a therapeutic rather than a diagnostic
technique.
This investigation is only undertaken once a bleeding tendency has been excluded and
the patient’s prothrombin time is normal.
Antibiotics should be given prior to the procedure.
Under fluoroscopic control, a needle (the Chiba or Okuda needle) 15 cm long and 0.7
mm in diameter is advanced into the liver through the eighth intercostal space in the
midaxillary line to a point about 2 cm short of the right margin of the vertebral
column.
The stilette is then removed and while injecting contrast (e.g. meglumineiothalamate 60
%, w/v) the needle is slowly withdrawn until contrast is seen entering a bile radical.
Addition to this technique enables placement of a catheter into the bile ducts to provide
external biliary drainage or the insertion of indwelling stents. The scope of this
procedure can be further extended by leaving the drainage catheter in situ for a
number of days and then dilating the track sufficiently for a fine flexible
choledochoscope to be passed into the intrahepatic biliary tree in order to diagnose
strictures, take biopsies and remove stones.
Peroperative cholangiography
During cholecystectomy a catheter can be placed in the cystic duct and contrast
injected into the biliary tree. The technique defines the anatomy and excludes the
presence of stones.
With improved preoperative imaging and a more careful operative approach the value
of this technique is debatable.
The limitation of the technique using single plates can be overcome by an X-ray image
intensifier with a television monitor which enables a much more accurate diagnosis of
biliary pathology.
Operative biliary endoscopy (choledochoscopy)
At operation a flexible fibre-optic endoscope can be passed down the cystic duct into
the common bile duct enabling stone identification and removal under direct vision.
The technique can be combined with an X-ray image intensifier to ensure complete
clearance of the biliary tree. After exploration of the bile duct, a tube can be left in the
cystic duct remnant or in the common bile duct (a T-tube) and drainage of the biliary
tree established.
After 7—10 days, a track will be established.
This track can be used for the passage of a choledochoscope to remove residual stones
in the a wake patient in an endoscopy suite. This technique is invaluable in the
management of difficult stone disease and prevents the excessive prolongation of an
operative exploration of the common bile duct.
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Congenital abnormalities of the gall bladder and bile ducts
Embryology
The hepatic diverticulum arises from the ventral wall of the foregut and elongates into
a stalk to form the choledochus.
A lateral bud is given off which is destined to become the gall bladder and cystic duct.
During early foetal life the gall bladder is entirely intrahepatic.
1-Absence of the gall bladder
Occasionally the gall bladder is absent. Failure to visualise the gall bladder is not
necessarily a pathological problem.
2-The Phrygian cap
The Phrygian cap is present in 2-6% of cholecystograms and may be mistaken for a
pathological deformity of the organ.
3-Floating gall bladder
The organ may hang on a mesentery which makes it liable to undergo torsion.
4-Double gall bladder
Rarely, the gall bladder is twinned. One of them may be intrahepatic.
5-Absence of the cystic duct
This is usually a pathological, as opposed to an anatomical anomaly and indicates the
recent passage of a stone or the presence of a stone at the lower end of the cystic duct
which is ulcerating into the common bile duct.
The main danger at surgery is damage to the bile duct, and particular care to identify
the correct anatomy is essential before division of any duct.
6-Low insertion of the cystic duct
The cystic duct opens into the common bile duct near the ampulla.
All variations of this anomaly can occur.
At operation they are not important.
Dissection of a cystic duct which is inserted low in the bile duct should be avoided as
removal will damage the blood supply to the common bile duct and can lead to stricture
formation.
7-An accessory cholecystohepatic duct
Ducts passing directly into the gall bladder from the liver do occur and are probably
not uncommon. large ducts should be closed but before doing so the precise anatomy
should be carefully ascertained.
Extrahepatic biliary atresia
A etiology and pathology
Atresia is present in 1/ 14 000 live births, and affects male and females equally.
The extrahepatic bile ducts are progressively destroyed by an inflammatory process
which starts around the time of birth. Intrahepatic changes also occur and eventually
result in biliary cirrhosis and portal hypertension.
The untreated child dies before the age of 3 years of liver failure or haemorrhage.
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The inflammatory destruction of the bile ducts has been classified into three main
types:
• Type I — atresia restricted to the common bile duct;
• Type II — atresia of the common hepatic duct;
• Type III — atresia of the right and left hepatic ducts.
Associated anomalies include, in about 20% of cases, cardiac lesions, polysplenia, situs
inversus, absent vena cava and a pre duodenal portal vein.
Clinical features
About one-third of cases are jaundiced at birth.
In all jaundice is present by the end of the first week and deepens progressively.
The meconium may be bile stained but later the stools are pale and the urine is
dark. Prolonged steatorrhoea gives rise to osteomalacia (biliary rickets).
Clubbing and skin xanthomas, probably related to a raised serum cholesterol,
may be present.
Pruritis is severe.
Differential diagnosis
This includes any form of jaundice in a neonate giving a cholestatic picture. Examples
are
1. alpha1-antitrypsin deficiency,
2. cholestasis associated with intravenous feeding,
3. choledochal cyst and inspissated bile syndrome.
4. Neonatal hepatitis is the most difficult to differentiate. Both extrahepatic biliary
atresia and neonatal hepatitis are associated with giant cell transformation of the
hepatocytes. Liver biopsy and radionuclide excretion scans are essential.
Treatment
Patent segments of proximal bile duct are found in 10 per cent of type I lesions.
A direct Roux-en-Y anastomosis will achieve bile flow in 75 %, but progressive fibrosis
results in disappointing long-term results.
Type II and III are treated by the Kasai procedure, in which radical excision of all bile-
duct tissue up to the liver capsule is performed.
Postoperative complications include
Bacterial cholangitis,
hepatic fibrosis
portal hypertension, with one-third having variceal bleeding.
Liver transplantation may be considered in the failures.
Congenital dilatation of the intrahepatic ducts (Caroli’s disease)
This rare, congenital, nonfamilial condition is characterised by multiple irregular
sacular dilatations of the intrahepatic ducts separated by segments of normal or
stenotic ducts.
Biliary stasis leads to stone formation and cholangitis.
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The patients present in childhood or in early adult life.
Associated conditions include congenital hepatic fibrosis, medullary sponge kidney
and, rarely, cholangiocarcinoma.
The mainstays of treatment are antibiotics for the cholangitis and the removal of
calculi. As the condition can be limited to one lobe of the liver, lobectomy may be
indicated.
Choledochal cyst
Choledochal cyst is due to a specific weakness in a part of or the whole of the wall of the
common bile duct.
Anomalous junctions of the biliary pancreatic junction are frequently observed and
long common channels result in high levels of biliary amylase in 80 % of cases.
Common pancreatobiliary channels may be associated with repeated attacks of
pancreatitis.
The patient may present at any age with attacks of jaundice of obstructive type,
cholangitis and abdominal signs. In some patients a swelling may be detected in the
upper abdomen.
US=will confirm the presence of an abnormal cyst and (MRI) scan will reveal the
anatomy; in particular, the relationship between the lower end of the bile duct and the
pancreatic duct.
It appears that the anomaly is premalignant; carcinoma of the biliary tract is a well-
recognised complication and carries a poor prognosis, and therefore excision is the
appropriate management.
Radical excision of the cyst is the treatment of choice with reconstruction of the biliary
tract using a Roux-en-Y loop of jejunum.
Other procedures have been shown to be ineffective and associated with recurrent
attacks of cholangitis.
Trauma
Injuries to the gall bladder and extrahepatic biliary tree are rare.
They occur as a result of a penetrating wound or a crush injury.
Operative trauma is perhaps more frequent than external trauma.
The physical signs are those of an acute abdomen.
The treatment is cholecystectomy for gall bladder injuries and if the bile duct is
damaged then drainage using a T-tube to the bile duct and a drain to the site of damage
is appropriate. Many will stricture and these can be secondarily be repaired by a Roux-
en-Y anastomosis.
Torsion of the gall bladder
This is very rare and relies on a long mesentery which often occurs in an older patient
with a large mucocele of the gall bladder.
The patient presents with extreme pain and an acute abdomen.
Immediate exploration is indicated with cholecystectomy as the only treatment.