The Cholecystokin Provocation HIDA Test: Recreation of Symptoms is Superior to Ejection Fraction in Predicting Medium-Term Outcomes

The (99m) technetium labelled hepato imino diacetic acid (HIDA) scan is widely used in the investigation of patients with typical biliary pain but whose trans-abdominal ultrasound scan (US) is normal. Although the standard measure by which the HIDA scan is deemed positive is the presence of an ejection fraction (EF) of < 35% following provocation with cholecystokinin (CCK), there still remains debate as to the usefulness of this measure. The aim of this study was to compare the roles of EF and symptom provocation following CCK infusion in relation to the outcome following laparoscopic cholecystectomy (LC). More specifically, we aimed to review the resolution of symptoms for our significant population of patients with normal HIDA scan EFs for whom surgery has traditionally been deemed inappropriate. All patients undergoing LC for a presumed diagnosis of biliary dyskinesia were identified from a prospectively maintained database. Data were collected regarding pre-operative symptoms, EF and symptom provocation during the CCK HIDA scan, histological findings, early symptomatic outcome, and medium-term follow-up. During the period from March 2006 to October 2009, 42 patients with biliary symptoms but a negative US were referred for assessment by a single surgeon. There were 31 women and 11 men with a mean age of 39.0 +/- 12.6 years. All underwent a CCK HIDA scan of which 17 were positive with an EF < 35% and the remaining 25 were negative. All patients reported recreation of symptoms following administration of CCK. All gallbladders were delivered intact for histological assessment and all but one showed evidence of chronic cholecystitis. At each postoperative visit, approximately 2 weeks following the procedure, all patients reported resolution of symptoms. After a mean of 18.7 +/- 12.1 months symptom recurrence had been noted in only one of 42 (2.4%). The CCK HIDA scan is a useful study in the investigation of acalcalous cholecystitis; however, we would suggest that recreation of symptoms following CCK provocation is superior to EF for the identification of underlying chronic cholecystitis. Indeed, a normal gallbladder ejection fraction does not necessarily rule out a biliary aetiology of symptoms for this patient population.