title: Pancreatographic investigation of the pancreatic duct system.
abstract: BACKGROUND
  Embryologically, the pancreatic duct system develops by the fusion between the dorsal and ventral pancreatic bud ducts. It has been suggested that the proximal part of the main dorsal pancreatic duct partially regresses to form the accessory pancreatic duct (APD). Aim of this study was to clarify the anatomy of the pancreatic duct system of the head of the pancreas and investigate the embryology of the normal pancreatic duct system.
  
  
  METHODS
  We reviewed endoscopic retrograde pancreatography of normal pancreatic heads (n = 256) and pancreas divisum (n = 36), focusing on long inferior branches arising from the APD and the main pancreatic duct (MPD). The accessory pancreatograms were divided into two patterns of course and shape, the long type (171 cases) and the short type (85 cases) according to the length of the MPD from the orifice to the junction with the APD. The long-type APD formed a straight line and joined the MPD at the neck portion of the pancreas. The short-type APD joined the MPD near its first inferior branch.
  
  
  RESULTS
  The shape of the long-type APD was quite similar to that of the dorsal pancreatic duct of pancreas divisum. The short-type APD was less likely to have a long inferior branch arising from the APD. The length of the APD from the orifice to the first long inferior branch was similar in the long-type APD (19.4 +/- 4.0 mm) and in the short-type APD (18.8 +/- 4.2 mm). The first long inferior branch from the long-type APD passed though the MPD near the origin of the inferior branch from the MPD, whereas the short-type APD joined the MPD near its inferior branch.
  
  
  CONCLUSIONS
  There are two types of APD. The long-type APD was quite similar to the shape of the dorsal pancreatic duct of pancreas divisum, and seems to represent a continuation of the main duct of the dorsal pancreatic bud. The short-type APD was less likely to have a long inferior branch, and seems to be formed by the most proximal part of the main duct of the dorsal pancreatic bud and its long inferior branch.
authors.affiliation: Department of Internal Medicine, Tokyo Metropolitan Komagome Hospital, Bunkyo-ku, Tokyo 113-8677, Japan. kamisawa@cick.jp
authors.forename: T
authors.initials: T
authors.lastname: Kamisawa
authors.forename: Y
authors.initials: Y
authors.lastname: Tu
authors.forename: N
authors.initials: N
authors.lastname: Egawa
authors.forename: K
authors.initials: K
authors.lastname: Tsuruta
authors.forename: A
authors.initials: A
authors.lastname: Okamoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002760:Cholangiopancreatography, Endoscopic Retrograde; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D018709:Statistics, Nonparametric