SURGICAL ANATOMY OF THE PAPILLA OF VATER AND BILIOPANCREATIC DUCTS

The present research was aimed at defining the surgical anatomy of the biliopancreatic ducts and of Oddi's sphincter. The numerous anatomic variations of the papilla, the millimetric distribution of its muscle fibres, and any morphological detail of clinical significance have bee n investigated. An integrated analysis of radiographic, tridimensional (casts), and histologic findings has been carried out in 49 of 64 aut optic bilio-duodeno-pancreatic specimens. Exact limits of the choledoc us and Wirsung sphincters were defined. A consistent accumulation of c ircular muscle fibres could be seen, on the choledocus duct side, up t o a mean distance of 13.6 mm from the papillary pore. However, more ra refied fibres were present up to 20.5 mm. Muscle fibres were seen to s top roughly on the pancreatic duct side at 7.3 mm from the papillary p ore. The beginning of the sphincter was observed 2-3 mm above the papi llary pore. There was no evidence suggesting the presence of upper, mi ddle, and lower biliary sphincters. Five anatomic diversities of the W irsung-choledocus confluence were found. The Y type was the most frequ ent (61.2%), followed by the U type (22.4%), V (14.3%), and II (2.1%). Santorini's duct with a normal papilla was present in 16 per cent of the cases. These data along with other interesting observations on ant ireflux mechanisms (Santorini's valves) and on the ductal space orient ation appear to be useful guidelines for a physiopathological understa nding of bilio-pancreatic diseases and for any therapeutic procedure o n these structures.