Hepatobiliary Scintigraphy in Evaluation of Sphincter of Oddi Dysfunciton in Post-Cholecystectomy Patients.

Introduction: Sphincter of Oddi dysfunction (SOD) refers to a functional obstruction of the sphincter of Oddi leading to hepatobiliary-type pain. Historically, the gold standard for diagnosis of SOD has been the detection of elevated sphincter pressure via manometry; however, this is an invasive procedure that carries with it a substantial risk of inducing pancreatitis. Hepatobiliary scintigraphy with cholecystokinin (HIDA-CCK) stimulation is a less-invasive, alternative to manometry; however, its clinical utility in the context of SOD is unclear. This retrospective study thus sought to evaluate the utility of HIDA-CCK in the evaluation of SOD in patients with right upper quadrant pain post- cholecystectomy. Patients & Methods: We retrospectively evaluated 86 patients post cholecystectomy patients (10 male, 76 female; mean age = 56) whom had undergone HIDA-CCK studies between January 2012 - June 2019 after presenting with abdominal pain. The study consisted of the injection of 5.0 mCi Tc-99m mebrofenin and, after visualization of the small bowel, infusion of 0.02 ug/ kg CCK over a 60-minute interval. Persistent visualization of radioactivity within the common bile duct post-CCK infusion served as diagnostic for SOD.

Results: Of the 86 patients included in the study, eight patients were positive for SOD via HIDA-CCK. Of these patients, one underwent ERCP sphincterotomy without symptom resolution, five were treated with medical management without symptom resolution, and 2 were lost to follow up. Of the remaining 73 patients with negative HIDA-CCK scans and with no history of prior SOD, one underwent sphincterotomy at an outside institution - which lead to transient symptom resolution followed by recurrence after several months. No interventions aimed at addressing SOD were taken in the remaining 72 patients.

Conclusions: Only a minority of post cholecystectomy patients referred for HIDA-CCK test were positive. At our center the positivity rate for SOD was 9.3%. Interestingly, those with positive tests were often treated medically rather than with sphincterotomy and showed little to no symptom resolution. Sphincter of Oddi Dysfunction remains a challenging complication in post-cholecystectomy patients. Clinical outcomes were difficult to ascertain in a number of patients due to the presence of co-morbidities with overlapping symptom profiles. The trend towards medical management in lieu of more invasive treatments such as ERCP sphincterotomy aligns with recent literature cautioning against the aggressive treatment of SOD without clear evidence of structural abnormalities and positive findings on manometry. The lack of correlation between positive SOD findings and responsiveness to therapy also meshes well with recent literature that calls into question the clinical utility of SOD diagnoses made via HIDA-CCK