Ultrasound secretin test in patients with pancreas divisum--an aid in the diagnosis of papillary or dorsal duct stenosis?

BACKGROUND

Pancreas divisum is a common anatomical variant of pancreatic ductal anatomy. Obstruction of the accessory papilla could cause pain and pancreatitis. It has been suggested that accessory papillary sphincter obstruction can be assessed by sonographic measurement of pancreatic duct diameter after secretin stimulation.

METHODS

We now compared our results of sonographic pancreatic duct diameter measurements before and during 10 min after intravenous injection of 1 CU secretin per kg body weight in 32 patients with confirmed pancreas divisum and 20 healthy volunteers.

RESULTS

The healthy controls showed a short-lasting duct caliber enlargement by about 93% of the basal diameter within 5 min after secretin injection. 25 pancreas divisum patients without pancreatic disease had a secretin-induced duct dilatation by about only 58%. In four patients with pancreas divisum and chronic pancreatitis no or just a slight duct dilatation was observed after stimulation. Two patients with dorsal duct stenosis as well as one patient with accessory papilla stenosis, however, showed a marked and prolonged secretin-induced duct enlargement by about 155% of the basal duct diameter.

CONCLUSION

In this investigation pancreatic duct response to secretin stimulation in pancreas divisum patients without pancreatic disease was less marked than in normal individuals. Thus, a particularly distinct and long-lasting duct dilatation could support the suspicion of accessory papilla or pancreatic duct stenosis.