The role of EHIDA Cholescintigraphy in the diagnosis of Human Sphincter of Oddi Dysfunction

Abstract

The aim of the study was to review the efficacy of a nuclear medicine diagnostic procedure at a local district general hospital. This test, called cholescintigraphy, aims to be able to diagnose patients who have problems with the release of bile from the bile duct. In particular some patients have problems with the function of the sphincter at the end of the bile duct and may potentially be diagnosed as suffering from sphincter of oddi dysfunction (SOD). One treatment avenue for this disorder is a surgical technique called endoscopic sphincterotomy in which an incision is made in the sphincter to induce a permanent widening of the opening.
The investigation involves a nuclear medicine technique during which an intravenously injected radio labelled tracer; (Technetium [99mTc] Cholecis) has its transit captured on a gamma camera as it travels through the liver and biliary tree to reach the duodenum. One particular measure was studied, this is described as, Texcretion the time taken for the 'tracer' to reach the duodenum. A high value for Texcretion of greater than 20 minutes was deemed as pathogenic and often resulted in the clinical decision that the patient should undergo an endoscopic sphincterotomy.
In this study the progress of 202 patients was followed using a retrospective analysis of the Nuclear Medicine Department's clinical records and the hospital's patient's notes. It was found that information for 16 of the patients was unavailable. Of the remaining 186, sixty-three patients suspected to have a cholecystitis were excluded from the study. Eighty patients were described as having a normal excretion of bile into the duodenum as determined by their Texcretion value as being less than 20 minutes. This left forty-three potential subjects. Twenty-one subjects were removed from the study, as their clinical progress could not be confirmed.
Thus, twenty-two subjects met the entry criteria for the major component of the study. Of these, three had a delayed release of tracer into the duodenum, although they still had an intact gall bladder. The remaining 19 all had previously had their gall bladder removed.
The 22 patients who had a delayed Texcretion value formed the cohort of patients who were subjected to the closest scrutiny. The progress of these patients was followed after they were treated by using the surgical technique of endoscopic sphincterotomy. Of this group five had a recurrence of their symptoms within a 12-month follow up period after the endoscopic sphincterotomy and 17 remained symptom free. A statistical comparison of the Texcretion values for the asymptomatic patients and those with a recurrence of their symptoms found no evidence that a longer Texcretion value was associated with this recurrence.
It is proposed that the clinical algorithm for diagnosis of the more problematic cases using cholescintigraphy followed by endoscopic sphincterotomy is generally successful in many cases. However, there is a need for further research to be able to identify patients who may not benefit from this sequence of diagnosis and treatment.