Study of extrahepatic biliary apparatus

Anandhi, P G (2008) Study of extrahepatic biliary apparatus. Masters thesis, Madurai Medical College, Madurai.


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INTRODUCTION: The study of extra hepatic biliary system is not only interesting but also useful to operating surgeons and radiologist. Recently increased rate of recent advances like “Living donor liver transplantation with duct to duct anastomosis and cholecystectomies performed by laproscopic procedures has made it imperative that the surgeon should have an adequate knowledge of the normal anatomy and its variations of extra hepatic biliary system. Recent investigations like magnetic resonance cholangio pancreatography (MRCP) require definitive knowledge about the anatomy of ductal system. The gall bladder plays an important role in the metabolisms of bile salts and subsequently that of fat. The gall bladder in addition to congenital anomalies has various metabolic, endocrine, obstructive, inflammatory and malignant diseases. In United States about 15% of population suffered from biliary tract disease (Cliason and Stevena in 1994) and this increased about 30% after the age of 45 and above. The gallstone obstructing the passage results in surgery about 80% of operations done upon gall bladder and bile ducts. The gall bladder has been an organ of speculation since the times immemorable. Jacopo da carpi (1522) “sometimes a man lack gall bladder; he is then of infirm health and shorter life. AIM OF THE STUDY: In no region of the human body is anomaly so common as in the biliary ducts and its adjacent blood vessels. In analysis of the literatures, many investigations have been carried about the variational anatomy of extra hepatic biliary apparatus. The importance of the variational anatomy of the extra hepatic duct system and its related vessels, in operative and invasive procedures, was first predicted by “Schachner” (1916). Abnormalities of the major ducts and accessory hepatic duct during Cholecystectomy is the most frequent cause for postoperative complications such as leakage of bile, fistula, necrosis of liver and hepatic failure. Biliary peritonitis leads to more serious trouble, if unrecognized during surgery. Similarly, arterial variations give rise to frequent hemorrhage during surgery. They may lead to injuries to duct, as during the process of clamping the anomalous vessels, ducts can also be included in ligature along with artery. Moreover, recognition of the structures in the calot’s triangle is considered to be important to minimize injuries of bile ducts and their related vessels. Narrow exposure and variational anatomy are the two major things that contribute to operative difficulties to the surgeons. It is like wise true, that anatomical knowledge is critical to prevention of injuries of the structures in hepatoduodenal ligament for interpretation of cholangiograms like Percutaneous Transhepatic Cholangiography (PTCA), Endoscopic Retrograde Cholagio Pancreatography (ERCP) and Magnetic Resonance Cholangio Pancreatographic (MRCP) procedures. The importance of variations in the extrahepatic biliary ductal system and calot’s triangle has been much observed by the surgical gastroenterologist, radiologist and general surgeons. Such an extensive clinically oriented topic created much interest in me which in turn provoked me to dissect and analyse the variations in extrahepatic biliary apparatus. MATERIALS AND METHODS: The study material consisted of: 1. 20 adult dissection room cadavers. 2. 30 enbloc postmortem specimens. Specimen collection: 1. Cadaver specimens were studied from dissection room. 2. Postmortem enbloc specimens were collected from the Department of Forensic Medicine, Madurai Medical College, Madurai. They were studied by conventional dissection method. The autopsies had been carried out by laparotomy midline incision from xiphisternum towards umbilicus. Incision extended laterally, from xiphisternum along the costal margin. Rectus muscle cut open in the midline. Peritoneum opened and entered into abdominal cavity. Stomach identified and its curvatures were defined. Pulling the lesser curvature, lesser omentum identified and its right free margin was defined and then hepatoduodenal ligament was identified. Now the greater omentum was cut transversely below it was pushed forwards towards right. Coils of small intestine was pushed towards left and 2nd part of duodenum was exposed and two ligature were put, one at the pyloric end of stomach and second just below 2nd part of duodenum. CONCLUSION: After studying 50 specimens’ of extrahepatic biliary apparatus, I have come to the following conclusion as follows. • A single gall bladder, extra hepatic, lodged in the fossa for the gall bladder, covered with peritoneum only on the posterior surface, with rugae in the interior was observed, in all the cases. Supernumerary gall bladder, intra hepatic gallbladder, left sided gall bladder, floating gall bladder, diverticula of gall bladder, phyrgian cap and septate gall bladder, although occasionally reported earlier was not noted in present study. • Hartman’s pouch was found in 4% in this study as a variation in the shape. • Extrahepatic union of right and left hepatic ducts to form the common hepatic duct was noted in 64% of cases, which appeared to be more common than intrahepatic union. • Cystic duct joins the common hepatic duct as an angular type in 80% cases. • Cystic duct joins the common hepatic duct at a point in which it makes common hepatic duct shorter and common bile duct longer. This is consider as normal level of union. • The average length of the ducts observed in the study are cystic duct 2 to 4 cms, common hepatic duct 1.5 to 3.5 cms and common bile duct 5.5 to 8 cms. • The arrangement of structures in hepatoduodenal ligament was that, common bile duct lies anterior and to the right of the ligament, hepatic artery lies anterior and to the left of duct system and portal vein larger and posterior to these structures. • The frequency of occurrence of accessory ducts was 14%. • The most commonly occurring ductal variations are presence of accessory right hepatic ducts terminating anywhere in common hepatic duct. • Cystic artery arising from the right hepatic artery is seen inside the calot’s triangle dividing into superficial and deep branches to supply the respective surfaces of gall bladder is noted to be the commonest arrangement. • Right hepatic artery arises from hepatic proper and seen to the left side of duct system. • Both cystic and right hepatic arteries passing posterior to the common hepatic duct to reach the calot’s triangle is seen to be more common. Hence many variations have found in this study, I believe the understanding of these variations is important not only for the anatomists, but definitely useful for operating surgeons and radiologist.

Item Type: Thesis (Masters)
Uncontrolled Keywords: extrahepatic biliary apparatus.
Subjects: MEDICAL > Anatomy
Depositing User: Subramani R
Date Deposited: 05 Oct 2019 07:59
Last Modified: 05 Oct 2019 14:07

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