EFFICACY OF BILE-ACID THERAPY FOR GALLSTONE DISSOLUTION - A METAANALYSIS OF RANDOMIZED TRIALS

To define better the efficacy of bile acid therapy for dissolution of radiolucent gallstones, we performed a meta-analysis of published tria ls from january 1966 to September 1992. Studies were identified using a MEDLINE computer search followed by an extensive manual search. The inclusion criteria used were: randomized trial, radiolucent gallstones in a visualizing gallbladder on oral cholecystography, and complete s tone dissolution confirmed by oral cholecystography or ultrasound. Stu dy results were pooled into 6 groups: placebo; high- and low-dose chen odeoxycholic acid (CDCA) (greater-than-or-equal-to 1 0 mg. kg/day and < 10 mg. kg/day); high- and low-dose ursodeoxycholic acid (UDCA) (grea ter-than-or-equal-to 7 mg. kg/day and < 7 mg. kg/day) and combined CDC A plus UDCA. Homogeneity calculations were performed and the percentag e of complete stone dissolution calculated for each group with 95 % co nfidence intervals. Of 66 trials identified, 23 comprising 1949 patien ts met the inclusion criteria. A total of 1062 patients were treated w ith CDCA, 819 with UDCA and 78 combination therapy. In studies > 6 mon ths' duration, high-dose UDCA completely dissolved stones in 37.3 % of patients (95 % C.I. 33-42 %), low-dose UDCA in 20.6 %) and high-dose CDCA 18.2% (95% C.I. 15-21 %). Based on only two studies, combination therapy achieved dissolution in 62.8 % (95% C.I. 51-74 %) of patients. Stones less than 10 mm dissolved significantly more frequently than s tones larger than 10 mm. This analysis shows that UDCA in doses greate r than 7 mg. kg/day taken for greater than 6 months will dissolve radi olucent gallstones in 3 8 % of patients. The combination of UDCA and C DCA may be more efficacious but this observation is based upon only 78 patients and requires confirmation in further randomized trials.