Reproducibility of endoscopic sphincter of Oddi manometry

Abstract

Results from endoscopic sphincter of Oddi manometry are being used to support the diagnosis of sphincter dysfunction in patients with unexplained pain after cholecystectomy. However, there are few data on the reproducibility of manometric records or motility diagnosis during a second test. In this study, the reproducibility of manometric records was assessed in 12 patients with pain after cholecystectomy by performing a second study after three months. Manometric tracings were evaluated without access to patients details and scored for sphincter basal pressure, frequency and amplitude of phasic contractions, propagation of phasic contractions, and responses to intravenous injection of cholecystokinin octapeptide (20 ng/kg). At the initial manometric study, four patients were diagnosed as normal, four as stenotic, and four as dyskinetic. Those diagnosed as normal and stenotic at the first study had an identical diagnosis at the second study. However, the diagnosis of dyskinesia was reproduced only in two of the four patients. In the other two patients a diagnosis of "stenosis" and "normal" was made at the second study. Cholecystokinin octapeptide (20 ng/kg intravenous bolus) produced inhibition of phasic contractions in all studies, both initially and at three months. We conclude that endoscopic sphincter of Oddi manometry is reproducible when the initial diagnosis is either normal or stenosis. However, the diagnosis of dyskinesia is poorly reproducible, perhaps due to the episodic nature of this manometric disorder or to progression of sphincter of Oddi dysfunction.

Sphincter of Oddi Manometry: Reproducibility of Measurements and Effect of Sphincterotomy in the EPISOD Study

“…This finding is consistent with 2 other studies in the last decade which involved both sphincters, but contrasts with the almost 100% reproducibility in earlier studies looking only at the biliary sphincter (Table). 1,[7][8][9][10] Significant lack of reproducibility is not surprising, since the measurements span only a few minutes and sphincter pressures are known to vary with the migratory motor complex. 11,12 Furthermore, there may be subtle differences in medication use in sedation/anesthesia, confounding the interpretation of sphincter measurements, as opiates are known to cause sphincter of Oddi spasm.…”

Normal sphincter of Oddi motor function

“…With current techniques, SOM is performed over relatively short periods of time, whether manometric finding s can be considered representative of overall sphincter function is now being questioned [26]. Prolonged transductal manometry detects short periods of either rapid phasic contractions or absence of phasic activity that are rarely seen during short ERCP recordings [1].…”

“…Validation studies of SOM have shown that interobserver error can be relevant in the absence of a standardized approach to interpretation of manometric recordings. However, observer errors become negligible when interpretation is done by experts or when interpretation follows an agreed-upon, standardized approach [26,27].…”

Clinical significance of sphincter of Oddi Dyskinesia

“…To facilitate anatomic orientation, contrast can be injected into the biliary or pancreatic system prior to manometry without affecting the basal SO pressure [31•]. If SO manometry is done by experienced investigators, the results are fairly stable and reproducible [32]. The major clinical drawback of SO manometry is the relatively high risk of iatrogenic pancreatitis.…”