Potential diagnostic value of pancreatic isoamylases for pancreaticobiliary maljunction with mild biliary dilatation in patients and a porcine model

Purpose The aim of this study was to evaluate the diagnostic value of serum pancreatic isoamylases for pancreaticobiliary maljunction (PBM) with mild biliary dilatation. Methods Serum and bile from 8 children with PBM and mild biliary dilatation (6 to 11 mm in diameter) and 4 young pigs with an anastomosis constructed between an isolated pancreas-duodenal segment and the gallbladder were studied for pancreatic isoamylases. Using an electrophoretic technique, the assay of pancreatic isoamylases was expressed by peak appearance rate (PAR). Serum from 20 healthy children served as normal controls. Results In the serum of the patients, preoperatively there were 5 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 100%; P4, 100%; and P5, 66.7%. These abnormal pancreatic isoamylases disappeared 2 weeks after operative treatment. In normal controls, there were only P1 (PAR, 40%) and P2 (PAR, 100%). Mild cylindrical dilatation (6 to 8 mm in diameter) of the common bile duct developed in the porcine PBM model. There were P1 (PAR, 100%) and P2 (PAR, 100%) in the porcine serum preoperatively. Thirty days and 60 days after establishing the model, there appeared in the serum 6 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 75%; P4, 100%; P5, 100%, and P6; 75%. The bile patterns of pancreatic isoenzymes in the patients and pigs were similar to those in serum. Conclusions Abnormal pancreatic isoamylases are characteristically present in the serum from both children and a porcine model of PBM and mild biliary dilatation. Assay for these abnormalities is promising to recognize this subset of patients in whom diagnosis remains a challenge.