Common bile duct

The common bile duct ( from Latin ductus "gear " duct " bile taping " ), also called the common bile duct, is the union of the common hepatic duct with the duct of the gallbladder ( cystic duct ) and serves for the transport of bile into the duodenum ( duodenum). In mammals, which lack a gall bladder (eg horses), the union of the right and left hepatic duct is called the common bile duct.

Anatomy

The common bile duct is a membranous - muscular tube of the people circa 2-3 mm in diameter and 10 cm length. He moves in with the portal vein and the hepatic artery through the hepatic portal. Then it passes through the small mesh behind the C- loop of the duodenum along the head of the pancreas. There he joins in humans with the main excretory duct of the pancreas ( pancreatic duct or pancreatic duct after the German anatomist JG Wirsung ) and opens to the passage of a sphincter ( papilla of Vater or major duodenal papilla ) on the inside of the C- loop of the duodenum. The blood supply of the common bile duct via the cystic artery.

Function and meaning

In the fasting state, the bile is dammed up in the gallbladder. There, the bile is collected and slightly thickened. Gall bladder serves as a reservoir.

After dinner, the flow returns to the cystic duct. The gallbladder contracts, empties the bile into the duodenum.

The flow velocity in the passage is too slow to be detected by an ultrasonic Doppler device. Appreciated it is 0.1-1 centimeters per second. The different flow directions are controlled by sphincter and by hormones, especially the cholecystokinin.

Diseases

A permanent occlusion of the bile duct is a serious health disorder. Firstly it is to jaundice and eventually liver failure. Due to medical measures, a closure of the bile duct must therefore be removed again.

The closure of the common bile duct can be caused by a gallstone ( choledocholithiasis ), a bile duct tumor or external compression (eg pancreatic head tumor). After a gall bladder operation, an accidental injury or cross-clamping (OP clip) lead to a complete closure.

Inflammation of the bile duct can occur in the form of bacterial cholangitis (secondary sclerosing cholangitis ), or as an autoimmune disease ( primary sclerosing cholangitis ). However, the resulting narrowing of the bile duct are usually found in the intrahepatic bile ducts

A atresia may occur as a congenital malformation. In the mouth area malformations are also possible: choledochal cyst (cystic enlargement of the common bile duct ), Choledochocele (3 to 6 cm cystic enlargement of the ampulla of Vater ), inner duodenal diverticulum ( outpouching of a non- regressed residual membrane in the duodenum at the level of the papilla of Vater ).

Study opportunities

Through a series of analysis possibilities of the common bile duct can be fairly well judged today. Most important are the ultrasound, various laboratory values ​​(gamma - glutamyl transferase, bilirubin, alkaline phosphatase) and Endoscopic Retrograde Cholangiopancreatography ( ERCP). Also, a percutaneous transhepatic cholangiography ( PTC), computed tomography ( CT) or magnetic resonance cholangiopancreatography (MRCP ) is possible.

The former practice of indirect representation of the Ganges by common bile contrast agent is applied now little more, since the ultrasound and ERCP provide faster and better statement and account for the previously more common contrast agent incompatibilities with it.

Ultrasound

An experienced examiner with a good ultrasound machine can usually quite fast choledochus make a valid statement about the ductus. For the less experienced examiners, it offers some pitfalls: The gait is usually less than 0.7 cm wide. In pathological condition, it can swell up to 2 cm in width. After gallbladder surgery, a width of up to 1.1 cm is still considered normal, because the bile duct can take over the memory function of the gallbladder partially.

The common bile duct enters the porta hepatis with a hepatic artery ( hepatic artery ) and the portal vein. It runs parallel to the portal vein and is crossed several times by the hepatic artery. Differentiation between portal vein and bile duct is not always possible especially for enlarged common bile duct without using a Doppler. The common bile duct passes from the liver coming from the upper right corner diagonally down to the left and turns to the caudal head of the pancreas.

The duodenum is usually full of air and makes the appearance of the common bile duct. In particular, the transition to the head of the pancreas is no longer so easily trace. Nevertheless, one can attempt to make the transition in the pancreatic head from the medial. Helpful for the study of the common bile duct is a good color Doppler, which can increase blood flow in the inferior vena cava, the portal vein and hepatic artery seen in the. In the common bile duct itself no color Doppler flow is detectable.

ERCP

A direct representation of the common bile duct is possible with X-ray contrast medium through the exploration of the papilla via an endoscope with side-view optics ( Endoscopic Retrograde Cholangiopancreatography, Endoscopic retrograde cholangiopancreatography ). In pathological findings, the therapy can be performed in the same session. There may be stones removed from the gear or bypassed stenoses with plastic or wire stents. Also malformations, such as Choledochocelen and inner duodenal diverticula are corrected endoscopic surgery. The first endoscopic Choledochocelen cleavage was from SE Miederer at the University of Bonn conducted in 1976.

CT and MRI

If the result of the ultrasound examination, no conclusive findings and is clinically still suspected biliary disease - eg stone disease, tumor or malformation - is an objectified, overlay poor and multidimensional imaging representable purposeful. For this purpose, computed tomography ( volume scan with MPR), which is readily available and inexpensive, but also means a radiation exposure as well as the MRT ( especially MRCP ), which is relatively expensive and only planned is possible. Both procedures are only finding representation. One possibility for intervention or therapy - as in the ERCP - is given only in exceptional cases.