Isolated Biliary Atresia
A rare, biliary tract disease characterized by progressive obliterative cholangiopathy of the intra- and extrahepatic bile ducts, occuring in the embryonic/ perinatal period, leading to severe and persistent neonatal jaundice and acholic stool.
Epidemiology
Biliary atresia (BA) prevalence at birth is 1/ 15,000-19,000 in Europe and North America.
Clinical description
Diagnosis is mostly made at 2-6 weeks of age, presenting with cholestasis, jaundice, acholia and possibly choluria and hepatomegaly, and sometimes vitamin K deficiency induced bleedings. Conjugated hyperbilirubinemia associated with an increase in γ-glutamyltransferase (GGT) are biochemical signs of the disease. The pathology is characterized by an ongoing inflammatory process of the entire biliary tree, although the disease is defined as an irreversible closure/ atresia of the extrahepatic bile ducts. In 10-20% of cases, biliary atresia is associated with other malformations (syndromic biliary atresia).
Etiology
The etiology is yet to be explained, but it is believed that it can be the result of the interaction of genetic, environmental, immune, and infectious factors, individually or in combination.
Diagnostic methods
Preoperative evaluation may include abdominal ultrasound, hepatobiliary scintigraphy, percutaneous liver biopsy, endoscopic retrograde cholangiopancreatography, and magnetic resonance cholangiopancreatography (MRCP). However, the definitive diagnosis is confirmed only by cholangiography.
Differential diagnosis
The differential diagnosis include other causes of neonatal cholestasis, for example infections, Alagille syndrome, alpha-1-antitrypsin deficiency, progressive familiar intrahepatic cholestasis (PFIC) and hormonal deficiencies.
Antenatal diagnosis
Signs of biliary atresia on prenatal ultrasonography has rarely been reported.
Genetic counseling
The disease is not yet identified to be hereditary. The genetic counseling is therefore not possible.
Management and treatment
Kasai portoenterostomy is the gold standard treatment, consisting in total extraction of the hilar fibrosis and subsequent biliary-enteric anastomosis, with favorable results in a maximum of 50% of cases, in which there is total restitution of the biliary drainage and normalization of total bilirubin levels.
Prognosis
The main prognostic factors to short- and long-term survival after surgery include age at surgery, type of biliary atresia, and experience of the center. Out of the possible complications, the most common are cholangitis, portal hypertension, and ongoing deterioration of the liver function with cirrhosis, leading to end-stage failure. Early liver transplantation is required in about 50% of the cases. Very long term survival with native liver decreases to about 25%.