Pancreaticobiliary Reflux with Normal and Relatively Long Common Channels Causing Cholelithiasis and Acute Pancreatitis in Children.

Pancreaticobiliary maljunction (PBMJ) has a long common channel (CC) that causes pancreaticobiliary reflux (PBR), which has been implicated in gallstones, cholangiocarcinoma, and pancreatitis. By contrast, PBR has occurred in cases with normal and longer CCs than normal but shorter than PBMJ. This pathophysiology has been primarily reported in adults and rarely in children. We sometimes observe this pathophysiology in children with pancreatitis and cholelithiasis. Herein, we report the clinical figures on the diagnosis of children with PBR in normal and relatively long CCs. This study included seven children who complained of refractory pancreatitis and cholelithiasis diagnosed with PBR in normal and relatively long CCs at our institution from August 2018 to September 2024. We measured the lengths of their CCs and sphincter of Oddi muscles via endoscopic retrograde cholangiopancreatography (ERCP) and cholangiography. In addition, amylase and lipase levels in bile juice were measured. All seven children demonstrated elevated amylase and lipase levels in bile juice obtained from gallbladder drainage and/or the common bile duct. ERCP and cholangiography indicated 2.2-5.5-mm lengths of CCs in their cases, which are normal lengths in two cases and relatively longer (0.3-1.1 mm: mean 0.6 mm) than the normal upper limit of CC in children in five cases, with their CCs shorter than the sphincters of Oddi. All children underwent extrahepatic bile duct resection and bilio-jejunal anastomosis, demonstrating no clinical symptom recurrence postoperatively. Some children with cholelithiasis and pancreatitis exhibit normal and relatively long CCs, causing PBR and inducing gastrointestinal diseases. Careful investigation by ERCP and cholangiography focused on the CC length, and pancreatic enzyme level assessments in bile juice are useful for diagnosing PBR in children with cholelithiasis and refractory pancreatitis.