Does gallbladder ejection fraction predict outcome after cholecystectomy for suspected chronic acalculous gallbladder dysfunction? A systematic review

The clinical utility of cholecystokinin-cholescintigraphy with calculation of a gallbladder ejection fraction (GBEF) in patients with suspected chronic acalculous gallbladder dysfunction (CAGD) remains controversial. It was our aim to critically evaluate the literature on the utility of the GBEF to predict outcome of patients with suspected CAGD. We performed an electronic search of the MEDLINE database for articles published between 1980 and 2002 and a manual search of references from bibliographies of identified articles. Only articles in English that concerned adults were screened. Data extracted included both qualitative and quantitative data reported on the study groups, cholescintigraphic technique, interventions, treatment outcomes, and trial methodologic characteristics. Twenty-three publications met the inclusion criteria. All were considered of poor methodologic quality. All but three studies were retrospective case series, only one was randomized, and none were adequately blinded, used adequate controls, or enrolled a sufficient number of patients. Five studies used a cut-off value for an abnormal GBEF that was different than the value used by the others, one study did not provide a cut-off value, and several did not report details of the cholescintigraphic technique (namely, the rate of cholecystokinin infusion). Studies varied in their outcome measures-and the criteria for success. The overall assessment of outcome in 19 studies concluded that calculation of a GBEF was useful in patients with suspected CAGD. The low methodologic quality of the studies precluded a meta-analysis approach to the data. Use of a calculated GBEF to diagnose and predict treatment outcome in suspected CAGD has not been adequately studied. Although most studies report utility of GBEF in predicting symptom outcome after cholecystectomy in patients with suspected CAGD, quality evidence is lacking, thereby precluding a definitive recommendation regarding its use. More high quality trials are needed.