The role of caerulein in the differential diagnosis of common-bile-duct stenosis.

The role of caerulein in differentiating functional narrowing of the distal common bile duct from organic stenosis was studied in 146 patients. Caerulein caused a generalized contraction of the extrahepatic biliary tract and a contraction of the sphincter of Oddi. It therefore improved opacification of the tract, particularly of the terminal portion, which is often not demonstrated by traditional techniques. The appearance of the duodenographic effect allowed for the evaluation of functional factors, which often play a role in stenosis of the sphincter of Oddi. Also, the reduction of bile-duct caliber revealed previously undetected filling defects.