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Updated: 10/25/07 11:31 AM |
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| HOME | HEAL | EDUCATE | RESEARCH | DIRECTORY | OUTREACH |
Authors: W. Volwiler, R.A. Willson, A.M. Larson, and J.D. Ostrow
Download Chapter ♦ Download Lecture Slides & Notes
Download Chapter ♦ Download Lecture Slides & Notes
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O. Other Diseases of the Gallbladder and Bile Ducts
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1. Cholecystitis
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| 90% of cholecystitis is associated with cholelithiasis |
Other than gallstones, the most common disease of the gallbladder is cholecystitis - both acute and/or chronic forms. Over 90% of patients with cholecystitis have stones in the gallbladder (cholelithiasis).
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a. Chronic cholecystitis
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| Chronic cholecystitis is most common |
The gallbladder wall is usually thickened and greyish, due to: a) fibrosis of the serosa and the muscular layers; b) infiltration of chronic inflammatory cells in the mucosa; and c) proliferation and penetration of mucosal pouches from the luminal surface deep into the lamina propria ( Rokitansky-Aschoff sinuses).
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| Impaired motility and epithelial transport functions |
The fibrosis and disruption of the muscular layer leads to decreased functional capacity of the gallbladder. The fasting volume may be reduced and the contractile response that empties the gallbladder in response to CCK is impaired. The epithelium has impaired ability both to acidify and to concentrate the bile.
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b. Acute cholecystitis
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Role of occlusion of gallbladder, stasis, infection and bacterial hydrolases and endotoxins.
The feared complication is, perforation of the gallbladder, with bile peritonitis |
Acute inflammation is usually superimposed upon chronic cholecystitis. Over 90% of cases follow impaction of a gallstone in the neck of the gallbladder or cystic duct, and secondary infection of the stagnant gallbladder bile occurs in about 75% of the cases. Acute inflammation of the gallbladder wall results from the toxic effects of unconjugated bile acids and lysolecithins released by bacterial hydrolases, as well as bacterial endotoxins, in the bile. Cases without stones in the gallbladder likely result from reflux of pancreatic juice into the biliary tree due to obstruction of the common channel at the ampulla of Vater.
The gallbladder is usually tense, distended and erythematous, often with splotchy discolorations from intramural hemorrhage. The serosal surface is often covered with fibrin, and dilated vessels may be readily apparent. The bile in the lumen may contain pus as well as blood. Histologically, there is edema, polymorphonuclear leukocytic infiltration, and vascular dilation; frank abscess formation and necrosis are not uncommon. If the acute inflammation subsides, the inflammatory reaction reverts to the chronic phase. Occasionally, the acutely inflamed gallbladder perforates and a localized subhepatic abscess or peritonitis, develops. |
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| NSAIDs often effective. If not, surgery needed. |
Treatment: Non-steroidal anti-inflammatory agents often relieve the pain and cause the inflammation to subside. If, however, peritoneal signs, pain and fever worsen, urgent removal or drainage of the gallbladder is indicated to prevent perforation.
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2. Bile Duct Obstruction
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| Dilation and bile stasis proximal to bile duct obstruction |
Obstruction of the extrahepatic and larger intrahepatic bile ducts (by stone, tumor or stricture) engenders bile stasis and progressive dilation of the branches of the biliary tree cephalad (proximal) to the block. The intralobular bile ducts in the portal triads dilate and reduplicate. If persistent, the reaction of adjacent tissue to retained bile salts eventually leads to a biliary (portal) cirrhosis. In the liver lobule, the bile canaliculi dilate, show inspissation of dehydrated bile, and may extravascate bile, causing localized bile necrosis of small groups of periportal liver cells (“bile infarcts”). Bile pigments accumulate prominently in hepatocytes as they become unable to secrete bilirubin conjugates into the canalicular bile.
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| Ischemia may cause strictures of ducts |
Fibrous strictures of the common bile duct may result from surgical procedures in or near the hilum of the liver. This is thought to be due to chronic ischemia, resulting from severing the small arteries supplying the duct. The complex and fragile arrangement of its arterial supply, renders the common bile duct particularly vulnerable to this event.
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3. Cholangitis
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Biliary obstruction predisposes to bacterial cholangitis
Acute cholangitis requires urgent treatment |
Bacterial sepsis in bile commonly develops in the stagnant bile behind persistent, benign (less often malignant) obstructions of the large, extrahepatic bile ducts, especially of the common bile duct. Bacteria penetrate the adjacent bile duct walls and may ascend the blocked duct lumen and lymphatics to cause multiple peribiliary abscesses in the liver, and sometimes bacteremia. Such patients usually have a very toxic illness with fever, chills, and leukocytosis. This is an ominous situation leading to a very high mortality if the infected obstructed bile is not promptly drained endoscopically, (ERCP), radiologically, or surgically.
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Next Section (P): Diseases of Hepatic Cell Injury » |
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