Classification of pancreaticobiliary maljunction and clinical features in children.

BACKGROUND: In 2015, the Committee on Diagnostic Criteria of the Japanese Study Group on Pancreaticobiliary Maljunction (PBM) proposed a classification of PBM into four types: (A) stenotic type, (B) non-stenotic type, (C) dilated channel type, and (D) complex type. To validate this classification and clarify the clinical features of the four types of PBM, a retrospective multicenter study was conducted.

METHODS: The study group of 317 children with PBM was divided into the four types of PBM. Clinical features, preoperative complications, operations, and postoperative pancreatic complications were evaluated.

RESULTS: All patients underwent excision of the extrahepatic bile duct. In type A, the age was younger and there was a higher incidence of cystic dilatation. Non-dilatation of the common bile duct was frequently seen in type B. Abdominal pain with hyperamylasemia was frequently seen in types B and C. In particular, the incidence of protein plugs and biliary perforation was high in type C (56.1% and 14.3%, respectively). The overall incidence of acute pancreatitis was 7.3%. Pancreatitis after excisional surgery was rare in the children in this study. Two patients with type D (0.6%) developed chronic pancreatitis postoperatively.

CONCLUSIONS: This proposed classification is simple and correlates well with clinical features.