XXXX : pathogenesis and treatment.

@entity1 @entity82 @entity1087 @entity70750 @entity101 @entity209 @entity843 @entity1578 @entity1463 @entity3851 @entity2876 @entity1146 @entity255
@entity2876 is a disorder of @entity1 in which there is obliteration or discontinuity of the extrahepatic biliary system, resulting in obstruction of bile flow. Untreated, the resulting cholestasis leads to progressive @entity70750 , @entity82 , and @entity1578 . @entity2876 has an incidence of approximately one in 10,000 live births worldwide. Evidence to date supports a number of pathogenic mechanisms for the development of @entity2876 . An infectious cause, such as by a virus, would seem most pausible in many cases. The clinical observation that @entity2876 is rarely encountered in premature @entity1 would support an agent acting late in gestation. However, no infectious or toxic agent has been conclusively implicated in @entity2876 . Genetic mechanisms likely play important roles, even regarding susceptibility to other specific causes, but no gene whose altered function would result in obstruction or @entity1146 of the biliary tree has been identified. The variety of clinical presentations support the notion that the proposed mechanisms are not mutually exclusive but may play roles individually or in combination in certain @entity1 . @entity2876 , when untreated, is fatal within 2 years, with a median survival of 8 months. The natural history of @entity2876 has been favorably altered by the Kasai portoenterostomy. Approximately 25 to 35% of @entity1 who undergo a Kasai portoenterostomy will survive more than 10 years without liver transplantation. One third of the @entity1 drain bile but develop complications of @entity82 and require liver transplantation before age 10. For the remaining one third of @entity1 , bile flow is inadequate following portoenterostomy and the @entity1 develop progressive @entity82 and @entity82 . The portoenterostomy should be done before there is irreversible @entity1463 of the intrahepatic bile ducts. Consequently, a prompt evaluation is indicated for any @entity1 older than 14 days with @entity1087 to determine if @entity70750 is present. If infectious, @entity209 are unlikely and if the @entity1 has findings consistent with @entity2876 , then exploratory laparotomy and intraoperative cholangiogram should be done expeditiously by a surgeon who has experience doing the Kasai portoenteostomy. @entity2876 represents the most common indication for pediatric liver transplantation, representing more than 50% of cases in most series. Transplantation is indicated when symptoms of @entity3851 occur, including recurrent @entity255 , progressive @entity1087 , portal @entity101 complications, @entity843 , decreased synthetic function, and growth/nutritional failure.
