CAN GALLBLADDER EJECTION FRACTION ON HIDA SCANS PREDICT ABNORMAL GALLBLADDER PATHOLOGY UPON CHOLECYSTECTOMY?

Abstract

Background: Cholecystokinin-Hepatobiliary Scan (HIDA) is often obtained to assess gallbladder function in patients with chronic abdominal pain. There are contradictory findings in the literature regarding the relationship between a diminished gallbladder ejection fraction (GBEF) and pathological abnormality of the gallbladder (GB). Dumont RC et al. found that 20 of 42 (48%) children who had a cholecystectomy for biliary dyskinesia had pathologic findings of chronic inflammation. However, Goncalves et al. showed 42 of 44 (95%) children showed chronic cholecystitis. Our aim was to evaluate the relationship of a diminished Gallbladder Ejection Fraction (GBEF) on HIDA with gallbladder pathology in a large population of pediatric patients. Methods: The medical records of 289 children who underwent cholecystectomy from 1998 - 2005 at Kosair Children's Hospital were reviewed. 104 of these children also underwent HIDA Scan. An abnormal value for the HIDA Scan was defined as <35% ejection fraction. Chi-square analysis, Positive Predictive Value, and Negative Predictive Value were calculated to determine whether diminished GBEF predicted GB pathology. Results: Patient ages ranged between 6 and 18 years. Of those with abnormal HIDA (96 patients), 55 (57%) had abnormal GB pathology. Of those with normal HIDA (8 patients), 5 (63%) had abnormal GB pathology. Abnormal GBEF Positive Predictive Value was 57%; Negative Predictive Value was 38%. Chi-square analysis revealed a p-value of 0.082 for abnormal HIDA scan inability to predict abnormal GB pathology. Conclusions: GBEF remains a controversial predictor in the determination of GB pathology. Although this study shows that abnormal HIDA scan statiscally predicts abnormal GB pathology, our findings suggest that an abnormal GBEF does not reliably indicate GB disease and delineates the limitations of the HIDA Scan. This further emphasizes the importance of the history and physical examination with regard to need for cholecystectomy.