Role of pressure and pancreatic reflux in the aetiology of choledochal malformation.

BACKGROUND: The aetiology of choledochal malformation is not known. Babbitt's hypothesis remains a popular concept, and assumes that activated pancreatic juice refluxes through the common pancreatobiliary channel causing mural damage and subsequent biliary dilatation. This hypothesis was tested clinically by evaluating the relationship between epithelial histology, choledochal pressure and degree of pancreatic reflux. METHODS: Children with choledochal malformation (cystic, type 1c; fusiform, type 1f; both intrahepatic and extrahepatic dilatation, type 4) operated on between January 1999 and October 2009 were identified. Where practical, choledochal pressure was measured on entry to the abdominal cavity, by puncture of the common bile duct, and bile was sampled for amylase content. Archival bile duct sections were scored using a semiquantitative epithelial lining/mural score (ELMS). RESULTS: A total of 90 children with choledochal malformations were operated on during the study interval. Histology was available for 73 children (median age 2·9 (interquartile range 1·3-7·9) years), 29 with type 1c, 31 with type 1f and 13 with type 4 malformations. There was a significant stepwise increase in pressure with choledochal morphology (median pressure 13, 17 and 20 mmHg for types 1f, 1c and 4 respectively; P = 0·037). There was an inverse relationship between choledochal pressure and bile amylase activity (r(s) = - 0·45, P < 0·001). High ELMS values were associated with higher choledochal pressure (P = 0·057) and low bile amylase activity (P = 0·002). CONCLUSION: High choledochal pressure (not bile amylase) was associated with more severe histopathological changes and choledochal morphology. These findings suggest that distal bile duct obstruction (and therefore high intraluminal pressure) contributes more to the key features of choledochal malformation than does pancreatic reflux.

Biliary atresia: lessons learned from the voluntary German registry.

INTRODUCTION: Aim of the study was to carry out a 5-year survey of German patients with biliary atresia (BA) and to launch a discussion regarding the feasibility of voluntary registries in unregulated healthcare systems. METHODS: A retrospective analysis of German BA patients born between 2001 and 2005, based on data collected from the voluntary European Biliary Atresia Registry (EBAR), was carried out and supplemented by data from all BA patients who underwent liver transplantation at the only 4 pediatric transplantation centers (pLTx) in Germany which are so far not registered at EBAR. Survival rates were calculated using Kaplan-Meier analysis and compared by Cox regression to determine the predictive value of age at surgery and the influence of the center size (fewer or more than 5 patients/study period) on overall survival and survival with native liver. RESULTS: A critical review of the 148 German EBAR charts revealed that 11 patients (7.4%) had no biliary atresia. The remaining 137 patients from EBAR together with 46 BA patients who underwent LTx without prior registration at EBAR were evaluated with a median follow-up of 39 months (range: 25-85 months). 29 hospitals performed a total of 159 Kasai procedures, but only 7 centers treated 5 or more patients (116 patients, range: 5-68), and 22 hospitals performed less than 5 KP (43 patients, range: 1-4). Primary LTx was performed in 21 patients (11.5%) and 3 patients died without surgical intervention. 16 patients were lost to follow-up (8.7%). Overall survival after 2 years was 83.3% (139 patients), including 105 patients (63%) who had undergone LTx and 34 patients (20.3%) with native liver. 28 patients died (16.7%), 8 after LTx (5.8%). The experience of the center was the only factor with a significant predictive value for jaundice-free survival with native liver (p=0.001). CONCLUSION: 25% of all German BA patients were not registered at EBAR, and 29 clinics were involved in the surgical management of BA patients. Therefore a new approach consisting of an internet-based decentralized registry for rare neonatal liver diseases is outlined which could improve the future management of patients with BA. The centralization of such patients at experienced centers with higher caseloads is necessary in Germany and would improve the outcome of patients with biliary atresia.

Preconceptional oral vaccination prevents experimental biliary atresia in newborn mice.

INTRODUCTION: Biliary atresia (BA) in humans resembles BA induced in Balb/c-mice by Rhesus Rotavirus (RRV). In mice, susceptibility to BA is ascribed to the lack of maternally derived immune protection. This study investigated whether vaccination of dams against RRV protected their offspring from developing BA. MATERIALS AND METHODS: Before mating, female mice were vaccinated orally with RotaTeq or Rotarix. Pups (n=243) from both test groups and a control group were intraperitoneally infected with RRV. Sacrifice of the animals was scheduled for days 7, 14 and 21 after infection. Then, gross and mircoscopia findings of the liver and the hepatoduodenal ligament gave evidence of BA, and hepatic viral load was tested by virus-specific real-time PCR, as well as plaque forming units. RESULTS: Two weeks after infection, the incidence of cholestasis was 100% in controls, 77% in pups of RotaTeq-vaccinated dams, and 56% in pups of Rotarix-vaccinated dams. However, in contrast to controls (incidence of BA: 82%) most pups in the test groups recovered (incidence of BA in pups of RotaTeq-vaccinated dams 11%; incidence of BA in pups of Rotarix-vaccinated dams 3%). Hepatic viral load was identical at various time-points in all pups, suggesting that differences in RRV clearance did not underlie this effect. CONCLUSION: In this mouse model, oral vaccination with RotaTeq and Rotarix prevented most RRV-induced BA. This provides a new approach to a better understanding of both the pathomechanism of BA development and the capabilities of the innate immune system. It also suggests a first approach for prophylaxis against BA.

[Predictive parameters in children with biliary atresia]. / Prognostische Marker bei Kindern mit Gallengangatresie.

Most children with biliary atresia require liver transplantation, and only about 20% survive in the long term with their native livers. Prognostic factors that determine disease progression are still lacking. This retrospective survey of 85 BA patients from 1993 to 2003 was aimed to evaluate prognostic factors using the log rank test. After 5 years 40% of the patients are alive with their native livers (35/85), 26 of them with normal bilirubin (31%). Age at Kasai operation (P=0.46), degree of liver fibrosis (P=0.95), and all laboratory test results before Kasai failed to correlate with outcome. Normal levels of bilirubin 3, 6, and 12 months after Kasai and of aspartate aminotransferase with gammaGT after 6 months are associated with survival with native liver. In conclusion our data demonstrate that a lack of predictive factors must prevent primary liver transplantation in BA patients.