Biliary manometry in swine: A unique endoscopic model for teaching and research

Biliary manometry, the 'gold standard' for the diagnosis of sphincter of Oddi dysfunction, is associated with technical and methodological problems. The lack of a suitable experimental model has hindered efforts to solve these problems. We report here on the first practical animal model for endoscopic biliary manometry, similar in technique to the procedure in humans. Piglets were sedated and intubated with a standard human duodenoscope. A standard water-perfused manometry catheter was inserted into the bile duct. The biliary sphincter was identified by a zone of high-pressure activity with superimposed phasic contractions. The sphincter responded normally to the administration of cholecystokinin and morphine by relaxation and contraction respectively. This model should be useful for training in biliary manometry, and facilitate technical innovations in the field. Since it is relatively atraumatic, it may also be better than existing surgical models for studying the normal physiology and pharmacology of the sphincter of Oddi.