ACCELERATED GALLSTONE DISSOLUTION IN METHYL TERT-BUTYL ETHER BY SONICATION - AN INVITRO STUDY

OBJECTIVES. The authors tested the effect of 195 KHz therapeutic ultrasound energy on gallstone dissolution in concert with methyl tert-butyl ether (MTBE) in vitro. METHODS. Sixteen sets of three gallstones matched for weight and appearance were selected from 16 surgically resected human gallbladders. One stone from each set was analyzed for its density pattern by computed tomography (CT) and biochemically for cholesterol content. Based on CT appearance, the stones were classified into eight noncalcified, four partially calcified, and four heavily calcified sets. The three stones were subjected to dissolution with MTBE: one with simultaneous sonication via an experimental ultrasound unit, one with manual stirring, and one acted as control without added treatment. RESULTS. Sonication reduced the dissolution time of noncalcified stones by 96% (range, 94%-98%; standard deviation [SD], 2%) relative to controls, and it was three to four times more effective than manual stirring. It was similarly effective in helping to dissolve partially calcified stones, but not heavily calcified stones. CONCLUSIONS. This study demonstrates the positive effect of sonication in accelerating gallstone dissolution with MTBE in vitro for stones without heavy calcification.