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. 

Other materials, such as bile acids and many xenobiotics, move from the hepatocytes into the bile-carrying canaliculi, which merge into larger ducts that follow the portal vein branches. The ducts merge into the hepatic duct from which bile drains into the upper part of the small intestine, the duodenum. The gall bladder serves to hold bile until it is emptied into the intestine. 

In health the liver is a large smooth organ covered in a protective cellophane-like membrane known as Glisson s capsule. This thin layer of connective tissue becomes thicker around the hilum, where the portal vein and hepatic artery enter the liver and where the right and left hepatic ducts and lymphatics exit. The surface of the liver is broadly... 

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... 

A case report of blastomycosis of the hepatobiliary i yi -tem describes the following conditions (39) development of chronic cholangitis in the area of the left hepatic duct with encroachment of the mycotic inflammation to the left lobe of liver in cases of predisposing and/or preexisting choledocholithiasis histological evidence of liver granulomas and periportal fibrosis marked increase in alkaline phosphatase and y-GT. (40)... 

During cholecystectomy, choledocholithiasis was found in 12-24%o of cases. A stone-free gall bladder does not exclude cholangiolithiasis. About 80% of the bile-duct stones are found in the choledochus, 15% in the common hepatic duct and 5% in the intrahepatic bile ducts. In obstructive cholangitis, the recognition and removal... 

Fig. 32.15 Staghorn calculus in the common bile duct and the two branches of the common hepatic duct (so-called Mercedes-star type) in primary sclerosing cholangitis...

Klatskin, G. Adenocarcinoma of the hepatic duct and its bifurcation within the porta hepatis. An unusual tumor with distinctive clinical and pathological features. Amer. J. Med. 1965 38 241 -256... 

Sato, M., Watanabe, Y., Tokul, K., Kohtani, T., Nakata, Y., Chen, Y., Kawachi, K. Hepatobihary cystadenocardnoma connected to the hepatic duct a case report and review of the literature. Hepato-Gastroenterol. 2003 50 1621 — 1624... 

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... 

Intrahepatic cholestasis caused by mechanical obstruction is also common, but is rarely associated with jaundice or with visibly dilated ducts on imaging studies, although it may be associated with increased direct bilirubin. Jaundice typically occurs only with lesions that are very large, or are located near the porta hepatis, where they may obstruct both hepatic ducts. Common causes of intrahepatic obstruction include (1) tumors (particularly metastases), (2) granulomatous diseases (such as sarcoidosis and tuberculosis), and (3) infiltrative processes (such as lymphoma, leukemia, and extramedullary hematopoiesis). 

Bile produced by hepatocytes is secreted into the bile canaliculi between adjacent hepatic cells. The wall of the canaliculus is formed by the plasma membrane of the hepatocytes, which are held together by tight junctions. Canaliculi arise near central veins and extend to the periphery of the lobules. The direction of bile flow in the canaliculi is centrifugal, whereas that of the blood flow is centripetal. Canaliculi coalesce to form ducts, which are lined by epithelium, and the ducts coalesce to form the right and left hepatic ducts. Outside the liver these ducts form the common hepatic duct. 

Right hepatic duct Left hepatic duct... 

Finally, an intraoperative cholangiogram will finally depict the anatomy of the biliary ducts and will assess whether the main right and left hepatic ducts have the caliber necessary to perform the Kasai hepatic portoenterostomy (Gazelle et al. 1998) (Fig. 4.2e). 

The blood supply to the bile duct system was studied by Northover and Terblanche in 1979 [29]. They found that the right and left hepatic ducts were supplied by numerous small vessels from the right and left hepatic arteries. The upper common bile duct is supplied by axial vessels from the retroduodenal or gastroduodenal arteries [30]. Therefore, necrosis of the right and left hepatic ducts may occur after radioembolization when the catheter is placed at the... 

Fig. 3.9. Coronal reformatted CT image (left) shows enhancing mass (arrow) in common hepatic duct obstructing the duct and causing jaundice. Findings are most consistent with cholangiocarcinoma. ERCP image (right) confirms stricture which was proven to he a cholangiocarcinoma at surgery...

Fig. 22.1a,b. Aberrant bile duct. Both coronal oblique MIP 3D heavily T2-weighted (a) andmangafodipir-trisodium-enhanced Tl-weighted (b) MR cholangiograms show the aberrant drainage of the right posterior duct into the common hepatic duct in this patient with a history of recurrent choledocholithiasis after cholecystectomy, a residual cystic duct is also appreciable... 

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... 

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