[Clinical evaluation of choledochoduodenal fistula near the duodenal papilla: association with separate openings of the pancreatic and biliary ducts].

A total of 1293 patients who underwent ERCP between 1980 and 1990 were reviewed. A parapapillary choledochoduodenal fistula (PCDF) was noted in 42 patients (3.2%). In order to study the frequency of PCDF, the patients were divided into groups of age of ten years. As a result, PCDF was formed to increase with advance in age. Thus the dispose is regarded as a "later on" disease. Thirty-one of these patients were included in the definite PCDF group, in which the distance between the papillar and fistulous opening was confirmed by cannulation or choledochography, and 11 in the questionable PCDF group, in which the distance was not confirmed, and thus the opening might be the separate openings of the pancreatic and biliary ducts (Mehnen's type I). The frequency of pneumobilia, biliary stone, history of cholecystectomy, biliary inflammation and obstruction were similar in the two groups. Only one patient suspected of having separate openings of the pancreatic and biliary ducts except the questionable PCDF was seen over the same period. This suggests that majority of the cases of separate openings of the pancreatic and biliary ducts, whose prevalence is estimated to be 2-4% in Japan, may be PCDF.