The relationship between biliary amylase and the clinical features of choledochal cysts in pediatric patients

Background Although the clinical features of choledochal cysts (CC) in different age groups have been widely studied, the causes of differences in clinical features are unknown. To determine the relationship between biliary amylase and the clinical features of CC in pediatric patients, clinical outcomes were compared in two groups with different amylase levels. Methods From May 1995 to August 2010, 80 patients under 18 years old who underwent choledochal cyst excision and hepaticojejunostomy and measurements of biliary amylase levels were allocated to a low-amylase-level group (amylase level<200 U/L, n = 26) and a high-amylaselevel group (amylase level>200 U/L, n = 54). Their medical records were retrospectively reviewed. Results The median age was 4 months (range = 17 - days-169 months) in the low group and 48 months (range = 22 days-147 months) in the high group (p = 0.008). In the low group, jaundice was the most common symptom, while abdominal pain was the main symptom in the high group. In histological findings, bile duct proliferation and cholestasis predominated in the low group and portal inflammation predominated in the high group. Radiological findings and preoperative laboratory data were also significantly different between the groups. Postoperative complications occurred in the high group only. There was no mortality in either group. Conclusion This study shows a relationship between biliary amylase level and clinical manifestations in pediatric patients with CC, implying that there are different underlying pathophysiologies with anomalous pancreaticobiliary ductal union (APBDU).