Comparison of Ultrasound-Secretin Test and Sphincter of Oddi Manometry in Patients with Recurrent Acute Pancreatitis

Manometry is considered the gold standard forevaluating sphincter of Oddi dysfunction. It hasrecently been demonstrated that the ultrasound (US)secretin test proposed a few years ago as a noninvasive test for the study of sphincter of Oddidysfunction yields a substantial percentage ofpathological findings in patients with acute recurrentpancreatitis. The aim of this study was to compare theresults of the US secretin test with sphincter of Oddimanometry findings in a consecutive series of patientswith recurrent acute pancreatitis. Forty-seven patientsadmitted to our gastrointestinal unit suffering from recurrent acute pancreatitis underwentultrasonographic measurement of the main pancreatic ductat baseline and for 60 min after maximal stimulationwith secretin at 1 IU/kg. According to the US secretin test findings in 35 healthy control subjects,the test results were considered to indicate pathologywhen the duct was still dilated after 20 min. Withinthree to seven days the same patients underwent perendoscopic manometry. Thirty-six patients(17 men, 19 women; mean age 41 ± 15 years) had asuccessful US secretin test and sphincter of Oddimanometry. Eleven patients (30.6%) presented normalmanometric findings. Two of these had an abnormal USsecretin test. Twenty-five patients had abnormalmanometry findings, revealing stenosis in 19 (52.7%) (17with abnormal US secretin test) and dyskinesia in six (five with an abnormal US secretin test).Compared to manometry findings, the US secretin testsensitivity and specificity for sphincter of Oddidysfunction were 88% and 82%, respectively. Inconclusion, most patients with recurrent acute pancreatitishave sphincter of Oddi dysfunction documented by both atthe US secretin test and sphincter of Oddi manometry;results of the US secretin test are reliable compared to sphincter of Oddi manometry, andtherefore the US secretin test may offer a validalternative to the more expensive and invasivemanometric procedure for assessing sphincter of Oddidysfunction in patients with recurrent acutepancreatitis.