Bile dilatation

In general, activation of alpha-1 adrenergic receptors causes a contraction of smooth muscle and of blood vessels, pilomotor muscles, dilator pupillae, vas deferens, nictitating membrane, splenic capsule, and sphincters of the intestine and urinary bladder and of the bile duct. An exception is the relaxation of the smooth muscle of the intestine. Prazosin [19216-56-9] indoramin [26844-12-2] and WB-4101 are relatively selective antagonists of these receptors. 

Dilatation of both the intrahepatic and extrahepatic ducts and the common bile duct is clearly seen by ultrasound, indicating obstruction, e.g. by gallstones or tumour. 

Varices Ultrasound scan -Doppler Dilated bile ducts... 

Aetiopathogenesis As with spider naevi, the capillary dilatation causing palmar erythema is attributed to an increased oestrogen content of the blood, a rise in bile acids or endotoxins and an activation of vasodilating substances with more numerous arteriovenous shunts and a hypercirculatory syndrome. Portal hypertension is seen as an important codeterminant. The blossoming of spider naevi and palmar erythema is also observed in the phenomenon of haemodynamic-related resistance to diuretics. 

Fig. 6.9 Blockage and dilation of the intrahepatic bile ducts ( lakeland plain ) in obstructive jaundice...

Songur, Y., Temudn, G., Sahin, B. Endoscopic ultrasonography in the evaluation of dilated common bile duct. X Clin. Gastroenterol. 2001 ... 

We regard stasis in dilated bile ducts as a contraindication of biopsy, although there are controversial views in the literature concerning this point. (108, 151) The risk of biliary complications should not be underestimated, especially since new examination techniques have indeed... 

Caroli s disease presents with multiple tubular structures, which correspond to focal cystic dilations of large interlobular bile ducts. The reduced density values of... 

Obstruction of a large bile duct leads to dilated intrahepatic bile ducts, which appear on CT scans as ramified linear or rounded structures with bile-equivalent density. Their luminal diameter increases progressively in the direction of the hilus. (47) Segmental dilation of the bile ducts may be indicative of a tumour. A dilation of the bile duct of >9 mm points to a peripheral obstruction, mostly near the papilla of Vater. 

Teefey, S., Baron, R.L., Schulte, S.J., Patten, R.M., Molloy, M.H. Patterns of intrahepatic bile duct dilatation at CT correlation with obstructive disease processes. Radiology 1992 182 139—142... 

This form of jaundice is initiated by a mechanical obstruction in the region of the extrahepatic or intrahepatic bile ducts, which is why the terms mechanical jaundice or obstructive jaundice are also common. The congestion of the bile flow is either incomplete or complete. Bile stasis results in dilation of the extrahepatic and intrahepatic bile ducts, allowing hepatomegaly to develop. (8, 9, 16, 19) (s. tab. 12.1)... 

Ultrasound examination is always indicated for the clarification of jaundice. The results determine the subsequent diagnostic steps. It is important to clarify whether the bile ducts are dilated, which is a hint for obstructive jaundice, (s. tabs. 6.8, 6.9) (s. p. 131)... 

ERC facilitates precise visualization of the bile ducts - this is also possible by means of PTC in cases of sonographically determined dilation of the bile ducts with suspected biliary obstruction. PTC is likewise indicated if ultrasound examination fails to produce evidence of enlarged bile ducts and/or ERC has proved inconclusive even though clinical and laboratory examinations suggest biliary obstruction, (s. pp 183, 184)... 

Morphology The morphologist uses the term cholestasis to describe the presence of bile in the hepatocytes as well as in hypertrophic Kupffer cells (= cellular bilirubino-stasis), particularly in the form of inspissated bile droplets and copper within the more or less dilated canaliculi (= canalicular bilirubinostasis). In extrahepatic cholestasis, bile is additionally found within the likewise mostly dilated interlobular bile ducts (= ductular bilirubinostasis) as well as in the parenchyma in the form of bile infarcts" or bile lakes . 

Histologically, cholestasis is moderate, focal and irregular, and the biliary capillaries are dilated, displaying biliary thrombi. Bile pigments may be detectable in the liver cells. Cell necroses and signs of inflammation are absent. 

In the case of non-dilated bile ducts, further specific laboratory parameters may be necessary for differential diagnosis, such as electrophoresis, immunoglobulins, hepatitis serology (s. p. 116) and tti-foetoprotein (s. p. 106). Determination of the AMA should always be considered. (s. p. 120) (s. tabs. 5.19-5.21 13.7)... 

If definitive clarification of cholestasis has still not been reached (even with MRC imaging), dilated bile ducts indicate an ERC or, if this is technically impossible, a PTC. The diagnostic sensitivity is 60-70%, the specificity 90-95 (-100)%. The ERC should also be used to visualize non-dilated bile ducts by means of direct presentation - e.g. in cases with suspicion of destructive primary biliary or sclerosing cholangitis as well as regionally restricted intrahepatic obstruction, (s. figs. 8.12, 8.13) (s. tab. 13.9)... 

Chronic choiangitis This disease shows dilated, proliferated, peripherally located ductules, which contain concentrated bile with degenerative epithelial changes. Large numbers of polymorphonuclear leucocytes are verifiable in the lumen and in the bile-duct wall leucocytic infiltrations spread to the neighbouring parenchyma. Increasing (lamellar) periductular fibrosis and... 

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