An effective method to study the pressure of the Sphincter of Oddi

The Sphincter of Oddi (SO) plays a vital role in maintaining the normal bile duct pressure, promoting gallbladder excretion and preventing from reflux. When sphincter of Oddi dysfunction (SOD) occurs, the incidence rate for bile duct infection and cholelithiasis will greatly increase. The Sphincter of Oddi Manometry (SOM) is the gold standard for examining the SOD - in which the Sphincter of Oddi pressure is well accommodated by the abundance of nerves and hormone receptors on the SO.

The research team led by Prof. Wu from General Surgery of Shengjing Hospital of China Medical University investagated the effects of H2-receptor blocking pharmacon, protease inhibitor and gastro kinetic agents on the human Sphincter of Oddi pressure measured by choledochoscope manometry, and reveals the effects of different drugs on the Sphincter of Oddi pressure. This was published on 14 October 2008 in the World Journal of Gastroenterology.

One hundred and seventy-five patients with T tube installed after cholecystectomy and choledochotomy were assessed by choledochoscope manometry. They were randomly assigned into groups of H2-receptor blocking pharmacon, protease inhibitor, and gastro kinetic agents. The Sphincter of Oddi basal pressure (SOBP), amplitude (SOCA), frequency of contractions (SOF), duodenal pressure (DP), and common bile duct pressure (CBDP) were scored and analysed.

They found that SOBP and SOCA were significantly decreased after Cimetidine administration, and no statistical difference was seen in the Famotidine group. In the Gabexate mesilate group, SOBP had decreased significantly. In the Ulinastatin group, SOCA decreased when Ulinastatin was given at the rate of 2500 U/min; when Ulinastatin administration was raised to 5000 U/ min, SOBP, SOF and SOCA all experienced a fall. SOBP and SOCA for Domperidone and SOCA for Mosapride groups all decreased distinctly after administration.

In conclusion, they adopted simple but effective choledochoscope manometry to study the SO motility, and explored the effect of many kinds of drugs on the SO rhythm, which profited our clinical practice. Their mechanisms of action warrant further study.