[Dissolution of cholesterol mixed stones with methyl tertiary butyl ether in vitro]

Methyl tertiary butyl ether (MTBE) has been proposed as a new therapeutic material for the dissolution of pure cholesterol mixed stones. To determine the effect of solvent circulation and fragmentation on dissolution of cholesterol mixed stone in MTBE, we carried out in vitro experiments. The following results were obtained: 1) The addition of 1% EDTA and 0.5% UDCA in MTBE enhanced the dissolution of cholesterol mixed stones (56 +/- 8% of initial weight after 3 hours vs. 48 +/- 5% of initial weight after 3 hours in MTBE alone). 2) Cholesterol mixed stones with circulation of MTBE + 1% EDTA + 0.5% UDCA were dissolved more rapidly than those without. 3) Under in vitro condition, when cholesterol mixed stones were fragmented with URAT-1M stone disintegrator, fragments of stones were dissolved 96% of initial weight in solvent circulation of MTBE + 1% EDTA + 0.5% UDCA after 3-6 hours. In conclusion, these data indicated that both fragmentation of cholesterol mixed stones and solvent circulation of MTBE + 1% EDTA + 0.5% UDCA considerably accelerated dissolution of cholesterol mixed stones in vitro.