Oral cholecystagogue cholescintigraphy: A systematic review of fatty meal options

Objectives Intermittent unavailability of sincalide for determination of gallbladder ejection fraction (GBEF) prompted increased usage of fatty meal cholecystagogues (FMCs). The aim of this systematic review was to identify the state of current FMC options in cholescintigraphy, focusing on the quality of corresponding normal GBEF values. Methods We performed an extensive literature search of the MEDLINE, Cochrane, and CINAHL databases without date or language restrictions with a broad spectrum of search terms. Selection criteria required both that the study use a FMC as part of a stimulated GBEF examination to gather data on normal volunteers or patients without evidence of gastrointestinal disease and that the meal used be described sufficiently for emulation. A cumulative point system was used to grade the quality of normal GBEF values: 1 point for screening ultrasound, 1 point for detailed screening questionnaire, 1 point for 20 or greater number of participants in a study, 1 additional point for 60 or greater number of participants in a study, 0.5 points for cursory screening questions, and 0 points when no screening process was mentioned. The meal was expressed in grams of fat per volume, when available. Results Twelve studies met inclusion criteria out of 15 studies claiming to report normal values. Two studies (17%) achieved a score of 3, 5 studies (42%) at 2 to 2.5, 3 studies (25%) at 1 to 1.5, and the remaining 2 studies (17%) at 0 to 0.5. Total number of participants examined ranged from 6 to 100. Meal composition varied widely. In 1 study, sham feeding was used. Most meals had components that could present problems to patients with relatively common dietary restrictions (ie, lactose intolerance, egg protein allergy, etc). Results for proposed normal values varied widely (from 16.3% to 85.6%). The commercial fatty meal products of Humana Infant Formula 1 and Ensure Plus offered the highest-quality normal values. Conclusions There is a need to establish high-quality normal GBEF range for a ubiquitous fatty meal (ie, a meal that would be widely available, easy to prepare, inexpensive, and free of sensitivity-provoking ingredients). A corn oil emulsion, has immense potential as an ideal FMC, limited currently only by its lack of established normal values. Currently, the highest-quality normal GBEF values available for FMC exist for 2 commercial products, Humana Infant Formula 1 and Ensure Plus. However, these products may not be readily available at some institutions, and neither one is free from dietary restrictions.