Comparison of ultrasound-secretin test and sphincter of Oddi manometry in patients with recurrent acute pancreatitis

Manometry is considered the gold standard for evaluating sphincter of Oddi dysfunction. It has recently been demonstrated that the ultrasound (US) secretin test proposed a few years ago as a noninvasive test for the study of sphincter of Oddi dysfunction yields a substantial percentage of pathological findings in patients with acute recurrent pancreatitis. The aim of this study was to compare the results of the US secretin test with sphincter of Oddi manometry findings in a consecutive series of patients with recurrent acute pancreatitis. Forty-seven patients admitted to our gastrointestinal unit suffering from recurrent acute pancreatitis underwent ultrasonographic measurement of the main pancreatic duct at baseline and for 60 min after maximal stimulation with secretin at 1 IU/kg. According to the US secretin test findings in 35 healthy control subjects, the test results were considered to indicate pathology when the duct was still dilated after 20 min. Within three to seven days the same patients underwent perendoscopic manometry. Thirty-six patients (17 men, 19 women; mean age 41 +/- 15 years) had a successful US secretin test and sphincter of Oddi manometry. Eleven patients (30.6%) presented normal manometric findings. Two of these had an abnormal US secretin test. Twenty-five patients had abnormal manometry findings, revealing stenosis in 19 (52.7%) (17 with abnormal US secretin test) and dyskinesia in six (five with an abnormal US secretin test). Compared to manometry findings, the US secretin test sensitivity and specificity for sphincter of Oddi dysfunction were 88% and 82%, respectively. In conclusion, most patients with recurrent acute pancreatitis have sphincter of Oddi dysfunction documented by both at the US secretin test and sphincter of Oddi manometry; results of the US secretin test are reliable compared to sphincter of Oddi manometry, and therefore the US secretin test may offer a valid alternative to the more expensive and invasive manometric procedure for assessing sphincter of Oddi dysfunction in patients with recurrent acute pancreatitis.