In vitro dissolution of cholesterol and brown pigmented gallstones: a comparison of MTBE, DMSO and BA-EDTA.

Background: Gallstones are a common problem in Taiwan and surgical removal remains the essential treatment. Successful dissolution of the stones with chemical solutions and then removal by endoscopic or percutaneous methods have previously been reported. We designed this study to find the ideal agent for dissolving gallstones.

Methods: Twelve chemical solutions with dimethylsulfoxide (DMSO), methyl tert-butyl ether (MTBE) and ethylenediamine tetra-acetic acid (EDTA) in different mixtures were tested to investigate their ability to dissolve gallstones in vitro. The dissolution of stones was performed at 37 degrees C and each procedure was repeated five to seven times.

Results: The solvent containing DMSO/MTBE (1/1) had a higher dissolving capacity for cholesterol stones, with solubility reaching 96.8% after 6 hours. The solution containing DMSO/MTBE (7/3) had the maximal solubility for calcium bilirubinate stones, with solubility reaching 22.9% after 6 hours. Also, we found that the intact stones of calcium bilirubinate became fragmented after treatment with the DMSO/MTBE solution without stirring.

Conclusions: The DMSO, MTBE and EDTA agents that we used effectively dissolved gallstones, especially cholesterol stones, in vitro. Further in vivo studies are necessary to confirm the efficacy and safety of these solvents before clinical application.