Choledochal Cyst and Anomalous Pancreatobiliary Ductal Union in Children

ABSTRACT

BACKGROUND: The etiology of choledochal cysts is unknown, but the theory of pancreatobiliary reflux through an anomalous pancreatobiliary ductal union (APBDU) is widely accepted. The aim of this study was to evaluate the correlation between choledochal cysts and APBDUs in children. METHODS: We retrospectively analyzed 33 pediatric patients with choledochal cyst who had undergone excision of the whole extrahepatic bile duct along with hepaticoenterostomy at the Division of Pediatric Surgery, Department of Surgery, Yonsei University College of Medicine, from 1993 to 1998. RESULTS: The mean age of the patients was 51 months, and the ratio of males to females was 12.3. Anatomical types were Ia (n=17, 52%), Ic (n=11, 33%), III (n=1, 3%), and IVa (n=4, 12%) in the Todani classification of biliary cysts. We performed endoscopic retrograde cholangiopancreatography, magnetic resonance cholangiopancreatography, or intraoperative cholangiopancreatography in all cases. An APBDU was identified in 24 patients (73%) right angle union (n=11, 33%), acute angle union (n=11, 33%), or a complex union (n=2, 6%) in the Todani classification of APBDUs. Type Ia cystic lesions correlated with right angle unions whereas Type Ic cylindrical lesions correlated with acute angle unions. The mean age of patients with a Type Ic, acute angle union was older than that of patients with a Type Ia, right angle union. In Type Ic, the amylase levels in serum and bile were elevated, but in Type Ia, they were not. CONCLUSIONS: APBDUs correlated highly with the shape of the extrahepatic dilatation, the age at onset, and the reflux of pancreatic juice. We think the excision of the entire extrahepatic duct along with a hepaticoenterostomy and appropriate evaluation of the APBDU are essential for the treatment of choledochal cysts in children.