The gall bladder
- The gall bladder is a reservoir for bile, a pear-shaped structure, 7-12cm long, with a capacity of 50 ml and capable of concentration of bile 5-10 times.
- The cystic duct is variable about 3 cm long, lumen of 1-3 mm and join the common hepatic duct (3 cm) to form the common bile duct (7 cm).
- Common bile duct has a supra-, retro-, infra- and intra-duodenal parts.
- The cystic artery a branch of right hepatic artery (80%) cross behind the common hepatic duct.
- The lymph drains to cystic lymph node which is at level of cystic duct.
Investigations of the biliary tract.
- Laboratory test
- Blood cp, LFTs, hepatitis B & C, APT, PT, urine RE, bile salts, serum amylase, etc.
- Ultrasonography
- Initial modality of choice as it is accurate, readily available, inexpensive and quick to perform.
- Plain radiograph
- 10% of gallstones are radio-opaque.
- Porcelain gall bladder (calcification of GB) is commonly (25%) associated with carcinoma of GB and strong indication for cholecystectomy.
- Gas may be seen in GB or its wall (emphysematous cholicystitis).
- In evaluation of difficult cases further investigations are.
- Computerised tomography
- Anatomy of liver, gall bladder and pancreas, especially of cancer.
- Magnetic resonance cholangiopancreatography (MRCP)
- Anatomy of biliary system.
- Endoscopic retrograde cholangiopancreatography (ERCP)
- These days more therapeutic role than diagnostic e.g.; extraction of stone, stenting, etc.
- Percutaneous transhepatic cholangiography (PTC)
- Anatomy of biliary system.
- Peroperative cholangiography
- Operative biliary endoscopy (choledochoscopy)
- Radioisotope scanning (HIDA, IODIDA)
- Helpful in diagnosing of function of liver, post operative bile leaks and iatrogenic biliary obstruction.
- Computerised tomography
