Biliary atresia pathophysiology: Difference between revisions
Ahmed Younes (talk | contribs) No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
<div style="-webkit-user-select: none;"> | <div style="-webkit-user-select: none;"> | ||
{|class="infobox" style="position: fixed; top: 65%; right: 10px; margin: 0 0 0 0; border: 0; float: right; | {| class="infobox" style="position: fixed; top: 65%; right: 10px; margin: 0 0 0 0; border: 0; float: right;" | ||
|- | |- | ||
| {{#ev:youtube|https://https://www.youtube.com/watch?v=pyT95PVUINI|350}} | |{{#ev:youtube|https://https://www.youtube.com/watch?v=pyT95PVUINI|350}} | ||
|- | |- | ||
|} | |} | ||
| Line 12: | Line 12: | ||
As the biliary tract cannot transport bile to the intestine, [[bile]] is retained in the liver (known as stasis) and results in cirrhosis of the liver. | As the biliary tract cannot transport bile to the intestine, [[bile]] is retained in the liver (known as stasis) and results in cirrhosis of the liver. | ||
There have been many theories about etiopathogenesis such as Reovirus 3 infection, congenital malformation, congenital CMV infection, autoimmune theory. This means that the etiology and pathogenesis of biliary atresia are largely unknown. However, there have been extensive studies about the pathogenesis and proper management of progressive liver fibrosis, which is arguably one of the most important aspects of biliary atresia patients. As the biliary tract cannot transport bile to the intestine, [[bile]] is retained in the liver (known as stasis) and results in cirrhosis of the liver. Proliferation of the small bile ductules occur, and peribiliary fibroblasts become activated. These "reactive" biliary epithelial cells in cholestasis, unlike normal condition, produce and secrete various cytokines such as [[CCL2|CCL-2 or MCP-1]], [[Tumor necrosis factor| Tumor necrosis factor (TNF)]], [[Interleukin-6| Interleukin-6 (IL-6)]], [[Transforming growth factor-beta|TGF-beta]], [[Endothelin| Endothelin (ET)]], and [[Nitric oxide| nitric oxide (NO)]]. Among these, TGF-beta is the most important profibrogenic cytokine that can be seen in liver fibrosis in chronic cholestasis. During the chronic activation of biliary epithelium and progressive fibrosis, afflicted patients eventually show signs and symptoms of portal hypertension (esophagogastric varix bleeding, hypersplenism, hepatorenal syndrome(HRS), hepatopulmonary syndrome(HPS)). The latter two syndromes are essentially caused by systemic mediators that maintain the body within the hyperdynamic states. | There have been many theories about etiopathogenesis such as Reovirus 3 infection, congenital malformation, congenital CMV infection, autoimmune theory. This means that the etiology and pathogenesis of biliary atresia are largely unknown. | ||
at 20 days of gestation The extrahepatic bile ducts appear as an out-pouching of the foregut , while the intrahepatic bile ducts become visible at 45 days, which arise from the primitive hepatocytes. The porta-hepatis is where the extra and intrahepatic bile ducts combine, and any flaw in this joining results in an obstructed biliary system. The isolated type of biliary atresia may be due to flawed assembly at the hepatic hilum. Similarities in the cytokeratin staining of the bile ducts in patients with biliary atresia and first-trimester fetal bile ducts supports the possibility that biliary atresia could occur due to the failure of the bile duct remodeling at the hepatic hilum with the persistence of fetal bile ducts. | |||
However, there have been extensive studies about the pathogenesis and proper management of progressive liver fibrosis, which is arguably one of the most important aspects of biliary atresia patients. As the biliary tract cannot transport bile to the intestine, [[bile]] is retained in the liver (known as stasis) and results in cirrhosis of the liver. Proliferation of the small bile ductules occur, and peribiliary fibroblasts become activated. These "reactive" biliary epithelial cells in cholestasis, unlike normal condition, produce and secrete various cytokines such as [[CCL2|CCL-2 or MCP-1]], [[Tumor necrosis factor| Tumor necrosis factor (TNF)]], [[Interleukin-6| Interleukin-6 (IL-6)]], [[Transforming growth factor-beta|TGF-beta]], [[Endothelin| Endothelin (ET)]], and [[Nitric oxide| nitric oxide (NO)]]. Among these, TGF-beta is the most important profibrogenic cytokine that can be seen in liver fibrosis in chronic cholestasis. During the chronic activation of biliary epithelium and progressive fibrosis, afflicted patients eventually show signs and symptoms of portal hypertension (esophagogastric varix bleeding, hypersplenism, hepatorenal syndrome(HRS), hepatopulmonary syndrome(HPS)). The latter two syndromes are essentially caused by systemic mediators that maintain the body within the hyperdynamic states. | |||
===Associated Conditions=== | ===Associated Conditions=== | ||
Associated anomalies include, in about 20% cases, | Associated anomalies include, in about 20% cases, | ||
*Cardiac lesions | *Cardiac lesions | ||
*[[Polysplenia]] | *[[Polysplenia]] | ||
Revision as of 09:31, 17 February 2022
| https://https://www.youtube.com/watch?v=pyT95PVUINI%7C350}} |
|
Biliary atresia Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Biliary atresia pathophysiology On the Web |
|
American Roentgen Ray Society Images of Biliary atresia pathophysiology |
|
Risk calculators and risk factors for Biliary atresia pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Pathophysiology
As the biliary tract cannot transport bile to the intestine, bile is retained in the liver (known as stasis) and results in cirrhosis of the liver.
There have been many theories about etiopathogenesis such as Reovirus 3 infection, congenital malformation, congenital CMV infection, autoimmune theory. This means that the etiology and pathogenesis of biliary atresia are largely unknown.
at 20 days of gestation The extrahepatic bile ducts appear as an out-pouching of the foregut , while the intrahepatic bile ducts become visible at 45 days, which arise from the primitive hepatocytes. The porta-hepatis is where the extra and intrahepatic bile ducts combine, and any flaw in this joining results in an obstructed biliary system. The isolated type of biliary atresia may be due to flawed assembly at the hepatic hilum. Similarities in the cytokeratin staining of the bile ducts in patients with biliary atresia and first-trimester fetal bile ducts supports the possibility that biliary atresia could occur due to the failure of the bile duct remodeling at the hepatic hilum with the persistence of fetal bile ducts.
However, there have been extensive studies about the pathogenesis and proper management of progressive liver fibrosis, which is arguably one of the most important aspects of biliary atresia patients. As the biliary tract cannot transport bile to the intestine, bile is retained in the liver (known as stasis) and results in cirrhosis of the liver. Proliferation of the small bile ductules occur, and peribiliary fibroblasts become activated. These "reactive" biliary epithelial cells in cholestasis, unlike normal condition, produce and secrete various cytokines such as CCL-2 or MCP-1, Tumor necrosis factor (TNF), Interleukin-6 (IL-6), TGF-beta, Endothelin (ET), and nitric oxide (NO). Among these, TGF-beta is the most important profibrogenic cytokine that can be seen in liver fibrosis in chronic cholestasis. During the chronic activation of biliary epithelium and progressive fibrosis, afflicted patients eventually show signs and symptoms of portal hypertension (esophagogastric varix bleeding, hypersplenism, hepatorenal syndrome(HRS), hepatopulmonary syndrome(HPS)). The latter two syndromes are essentially caused by systemic mediators that maintain the body within the hyperdynamic states.
Associated Conditions
Associated anomalies include, in about 20% cases,
- Cardiac lesions
- Polysplenia
- Situs inversus
- Absent vena cava
- A preduodenal portal vein