Objective evaluation of ampullary stenosis with ultrasonography and pancreatic stimulation.

Ultrasonography can detect changes in pancreatic and bile duct sizes after pancreatic stimulation by secretin or morphine and prostigmine. The effects of the two pharmacologic regimens on pancreatic duct dilatation were comparable and correlated with papillary stenosis determined at surgery, but the morphine and prostigmine combination produced more false-positive responses than did secretin. After administration of intravenous secretin (1 unit/kg), the pancreatic duct dilated in 83 percent of 12 symptomatic patients found at surgery to have a stenotic sphincter of Oddi and in 72 percent of 17 symptomatic patients found to have a stenotic accessory papilla associated with the pancreas divisum anomaly. Comparable dilatation occurred in 14 percent of 14 control subjects without suspected ampullary disease and in none of 10 patients with surgically disproved stenosis (p less than 0.001). The morphine and prostigmine combination produced more false-positive results in both the pancreatic duct and bile duct. Concomitant elevation of the serum amylase level and reproduction of pain were found to be of no discriminatory value. In patients whose pancreatic duct dilated preoperatively during secretin stimulation, dilatation did not occur after surgical sphincteroplasty. A positive test result was associated with a 90 percent success rate in preventing recurrent pancreatitis and ameliorating pain. A negative test result was associated with a 29 percent success rate. Ultrasonography of the pancreatic duct with secretin stimulation may provide objective criteria to supplement clinical judgment in selecting patients for sphincteroplasty to treat stenosis of either the sphincter of Oddi or the accessory papilla in pancreas divisum.