Repeated cholangiogram under pressure reveals rare type I-b1-β biliary atresia: A case report with diagnostic and surgical implications.

introductionBiliary atresia (BA) is a progressive cholestatic disease in neonates and infants, and early diagnosis and treatment significantly impact prognosis. Definitive diagnosis is based on cholangiogram findings, classifying BA into three main types. Among its variants, type I-b1-β-where the common bile duct is blocked, the distal duct is fibrous, and the tiny intrahepatic ducts are underdeveloped-is particularly rare. We describe a case in which high-pressure cholangiography clarified the anatomy and guided effective treatment. PRESENTATION OF CASE: A 71-day-old girl had jaundice and hepatosplenomegaly. Initial hepatobiliary scintigraphy demonstrated no biliary excretion into the intestine. During surgery, a laparoscopic cholangiogram visualized only the gallbladder. Converting to an open approach, we injected contrast under pressure through the cystic duct stump, which then outlined a narrowed common bile duct and small intrahepatic channels without passage into the duodenum, confirming type I-b1-β BA. A hepaticojejunostomy was performed, leading to green stool passage on postoperative day 1 and normalization of bilirubin levels by two months. At six months, she remained free of jaundice. DISCUSSION: This subtype is rare, and standard cholangiography may fail to visualize biliary anatomy. Repeated high-pressure imaging was critical for accurate classification and surgical planning. Unlike most BA variants treated with Kasai portoenterostomy, the presence of patent hilar ducts in this case supported hepaticojejunostomy, yielding favorable outcomes. Only one similar case has been reported.

conclusionHigh-pressure cholangiography is essential for diagnosing uncommon BA subtypes when initial imaging is inconclusive. In anatomically favorable type I-b1-β BA, hepaticojejunostomy can resolve cholestasis with good long-term results.