Sphincter of Oddi dysfunction in children with recurrent pancreatitis and anomalous pancreaticobiliary union: an etiologic concept

Background: The exact cause of recurrent pancreatitis among patients with anomalous pancreaticobiliary union is not known. Sphincter of Oddi dysfunction has been implicated as a mechanism. This study evaluated sphincter of Oddi function in children with anomalous pancreaticobiliary union and recurrent pancreatitis and assessed the results of endoscopic sphincterotomy in the management of this condition. Methods: We retrospectively reviewed 128 endoscopic retrograde cholangiopancreatographic (ERCP) studies performed on children older than 1 year and adolescents with pancreaticobiliary disease. In 64 instances, ERCP was performed because of recurrent pancreatitis. Nine patients underwent sphincter of Oddi manometry followed by endoscopic sphincterotomy, and these patients were included in this study. A basal pressure greater than 35 mm Hg was considered diagnostic for sphincter of Oddi dysfunction. Follow-up data were obtained retrospectively from the patients' relatives and referring physicians. Results: An anomalous pancreaticobiliary union was found in 18 of 64 (28%) patients with recurrent pancreatitis. The 9 patients who underwent sphincter manometry and endoscopic sphincterotomy were 5 girls and 4 boys 2.9 to 17 years of age (mean 7.8 years). A choledochal cyst was found in 7 of these 9 patients. Two patients had anomalous pancreaticobiliary union without common bile duct dilatation. All 9 patients had sphincter of Oddi dysfunction (mean basal pressure 96 +/- 37.8 mm Hg, range 48 to 156 mm Hg). The length of the common channel was 22.8 +/- 5.5 mm, and the length of the sphincter of Oddi segment was 12.1 +/- 1.9 mm (p < 0.001). In all patients the sphincter of Oddi segment was located within the duodenal wall. The mean follow-up period after endoscopic sphincterotomy was 26.4 months (range 18 to 38 months). Eight patients had excellent results defined as absence of symptoms and no subsequent episodes of acute pancreatitis. Treatment of 1 patient was considered moderately successful because the patient still had occasional pain without pancreatic enzyme elevation but no subsequent episodes of acute pancreatitis. One patient had mild postprocedural pancreatitis. Conclusions: Recurrent pancreatitis and anomalous pancreaticobiliary union are associated with sphincter of Oddi dysfunction in children and adolescents. Endoscopic sphincterotomy is beneficial to these patients.