Ultrasonic Monitoring of Wirsung Duct Following Secretin in Controls and in Chronic Pancreatitis Patients

Ultrasonic monitoring of the pancreas following secretin stimulation has shown to cause a marked dilatation of Wirsung duct; whether this phenomenon is due to the stimulation of pancreatic secretion and/or to the effect of secretin on the sphincter of Oddi (SO) motility is unknown. In the present study pancreatic scan after secretin was performed in 11 patients with nonpancreatic diseases after premedication with glucagon (inhibition of both pancreatic secretion and SO motility) or tyropramide (inhibition of SO motor function) and in patients with different degrees of pancreatic insufficiency. Serum immunoreactive trypsinogen (IRT) levels were measured in all the subjects during the test. Premedication with glucagon completely abolished both Wirsung enlargement and serum IRT increase, while tyropramide significantly reduced, but did not abolish, the response to secretin. These results suggest that both stimulation of pancreatic secretion and the increase of SO pressure are prerequisites for a full-blown occurrence of the secretin-induced modifications of Wirsung. Within chronic pancreatitis patients, the response to secretin was exaggerated in those with a still preserved pancreatic function and it was lacking in those with severe pancreatic insufficiency.