Biliary common hepatic duct

Outside the liver the common hepatic duct is joined by the cystic duct of the gallbladder and becomes the common bile duct (CBD). The extrahepatic and intrahepatic ducts are supplied with blood by a fine network of tiny arterial branches that originate from the hepatic and gastroduodenal arteries. As it has no other blood supply, the biliary tree is particularly susceptible to ischaemic injury, such as hepatic artery thrombosis or injury to the biliary plexus during laparoscopic surgery. This can result in extrahepatic and complex hilar and perihilar ischaemic strictures of the biliary tree. 

Quinn, R.J., Meredith, Ch., Slade, L. The effect of the Valsalva maneuver on the diameter of the common hepatic duct in extrahepatic biliary obstruction. J. Ultrasound Med. 1992 11 143-145... 

In 27 patients who received intrahepatic floxuridine, total dose 20-41 mg/kg extrahepatic biliary sclerosis was discovered by CT scan and ultrasound, followed by endoscopic retrograde cholangiopancreatography and/or percutaneous cholangiography in three cases (4). Radiological findings included complete obstruction of the common hepatic duct in one case, common hepatic duct stenosis in two cases, common bile duct obstruction in one case, and intrahepatic bile duct dilatation without identifiable obstruction in one case... 

Fig. 22.6a-c. Biliary lithiasis in a patient with hepaticojejunostomy. Coronal thin MIP 3D heavily T2-weighted MR chol-angiograms (a,b) show the presence of multiple stones into both the right hepatic duct and the pre-anastomotic common hepatic duct. Coronal thick MIP 3D heavily T2-weighted MR cholangiogram (c) better shows the dilation of the intrahepatic biliary system, the right and left hepatic ducts and the common hepatic duct... 

Bile is secreted by the liver, stored in the gallbladder, and used in the small intestine. It is transported toward the small intestine by the hepatic duct (from the liver) and the cystic duct (from the gallbladder), which join to form the common bile duct. Pancreatic juice is transported toward the small intestine by the pancreatic duct. The common bile duct and the pancreatic duct join to form the hepatopancreatic ampulla, which empties into the duodenum. The entrance to the duodenum is surrounded by the Sphincter of Oddi. This sphincter is closed between meals in order to prevent bile and pancreatic juice from entering the small intestine it relaxes in response to the intestinal hormone cholecystokinin, thus allowing biliary and pancreatic secretions to flow into the duodenum. 

The liver must be producing alkaline phosphatase to renew that on the outer surfaces of the bile canaliculi whose contents empty not into venules but into the common bile duct. The amount of alkaline phosphatase in bile is of a low order, and quantitatively can bear little comparison to that produced by the intestinal mucosa. There is the possibility, however, that the biliary alkaline phosphatase can be reabsorbed in an entero-hepatic circulation. 

An obstruction or occlusion of the common bile duct affects the clearance of the Tc-IDA complex into the duodenum, resulting in an increased transit time and an abnormal scintigram. The absence of biliary tract visualization in the presence of normal hepatic extraction indicates an acute common bile duct obstruction from a stone in the common bile duct (Fink-Bennett 1995). 

Surgical models also exit for evaluation of hepatic fibrosis. The most common method employed is ligation of the common bile duct in rats or mice. The subsequent response involves not only fibrosis but also proliferation of biliary epithelial cells, oval cells, portal inflammation, and, of course, cholestasis. With time, there is progression to biliary cirrhosis and hepatic failure. Relatively high mortality... 

Fig. 4.2. 25. Bile duct anastomotic stricture. A 37-year-old female status post fulminant acute hepatitis A, followed by orthotopic cadaveric liver transplant presenting now with abnormal liver function tests. Coronal thick-slab T2-weighted single-shot fast spin echo (SSFSE) MRCP image shows a short-segment stenosis (arrow) at the biliary anastomosis with upstream dilatation of the common bile duct. The remnant of the cystic duct (arrowhead) and a small amount of hyperintense fluid in the duodenal lumen (asterisk) are also seen...

The Group II (biliary tract) enzymes are abnormal usually when the serum bilirubin concentration is also abnormal. Most commonly used is alkaline phosphatase which is a highly sensitive indicator of biliary tract obstruction, perhaps because the enzyme is synthesized as an induced response to obstruction of even small bile ducts. Most techniques used to identify the origin of an elevated serum alkaline phosphatase are not very useful from a clinical viewpoint (23). The simultaneous measurement of GMT activity has been found to be useful in differentiating between the hepatic and bony origin of alkaline phosphatase. An increased GMT activity in a patient with an increased ALP activity is a good indication that there is biliary biliary tract disease (62,63). 

Extrahepatic biliary atresia may involve all or part of the extrahepatic bifiary tree. The gallbladder is usually absent. Involvement of the hepatic or common duct leads to the characteristic syndrome of severe cholestatic jaundice. It occurs in 1 in 10,000 births, with females more commonly affected than males. Jaundice and pruritus usually appear in the first week. Stools are pale and the urine is tea colored. Jaundice is deep, but the aminotransferases are only mildly elevated. If jaundice persists beyond 14 days of age, a direct or conjugated bilirubin measurement must be performed to exclude biliary atresia. If it is elevated, the urine should be tested for bile and the stool color inspected if the color is not green or yellow, biliary atresia is likely. Early identification of this condition is essential if these infants are to benefit fi"om the operation of portoenterostomy, which should be performed no later than 60 days after birth. If portoenterostomy is not successful, liver transplantation is the treatment of choice. Children rarely live beyond 3 years unless the lesion is surgically correctable. 

Intrahepatic biliary atresia is characterized by a paucity of intrahepatic bile ducts. Jaundice usually appears within the first few days of life. Serum bilirubin is elevated and serum cholesterol may be very high and lead to the formation of xanthomas. The hepatic histology is nonspecific, showing bile duct paucity, giant cells, inflammation, and fibrosis. Survival into adolescence is common, although growth is usually retarded. 

The liver can be involved in CF. Biliary cirrhosis secondary to bile duct obstruction occurs in as many as 18% of patients, whereas fatty infiltration occurs in about 30% of patients in a pattern unrelated to nutritional status. Bile ducts may be obstructed by inspissated mucus, which may lead to focal or multilobar cirrhosis. Such hepatic involvement can occur at any age but is more common with advancing age and can lead to portal hypertension, esophageal varices, and hypersplenism. The most common laboratory abnormality associated with hepatic involvement is elevated serum hepatic isoenzymes (gamma-glutamyltranspeptidase, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase)." ... 

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