Annular Pancreas in Thais

Objective: To study a congenital malformation of pancreas, the annular pancreas, and openings of pancreatic ducts. This abnormality can cause duodenal obstruction. Methods: The annular pancreas and duodenum of an 86-year-old Thai female cadaver was removed. The length and width of the annular pancreas were measured, as well as the internal diameter of the duodenum at the surrounded part and also the higher level. The openings of pancreatic duct were also carefully observed. Results: The second part of the duodenum was completely surrounded by the pancreatic tissue. The uncinate process extended over the anterior surface of the third part of the duodenum. The differences between the diameter of the duodenum at the surrounded part and at the higher level were 0.2 cm. there is no duodenal obstruction in this case. There were 2 openings of the pancreatic duct which opened to the second part of the duodenum. These ducts situated higher than the normal level, and were the primitive remains of the dorsal and ventral pancreatic buds. Conclusion: Not all the cases of the annular pancreas cause duodenal obstruction. In the cases that the pancreatic tissue loosely surrounds the duodenum, the diameters of the duodenum at the surrounding and at the slightly higher level are nearly the same. The pancreatic openings showed the primitive characters, i.e., there were 2 openings represented 2 origins of the pancreatic buds.