title: Accelerated gallstone dissolution in methyl tert-butyl ether by sonication. An in vitro study.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Radiology, Toronto Hospital, Ontario, Canada.
authors.forename: D S
authors.initials: DS
authors.lastname: Lu
authors.forename: C S
authors.initials: CS
authors.lastname: Ho
authors.forename: F S
authors.initials: FS
authors.lastname: Foster
authors.forename: J W
authors.initials: JW
authors.lastname: Hunt
authors.forename: E
authors.initials: E
authors.lastname: Yeung
authors.forename: J
authors.initials: J
authors.lastname: Ricketts
authors.forename: C
authors.initials: C
authors.lastname: McKinley
authors.forename: L C
authors.initials: LC
authors.lastname: Allen
mesh_terms: D002769:Cholelithiasis / Q000737:chemistry / Q000000981:diagnostic imaging / Q000628:therapy*; D002784:Cholesterol / Q000032:analysis; D004987:Ethers / Q000627:therapeutic use*; D005069:Evaluation Studies as Topic; D006801:Humans; D066298:In Vitro Techniques; D008096:Lithotripsy / Q000295:instrumentation / Q000379:methods*; D008738:Methyl Ethers; D012997:Solvents / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed
chemical_list: D004987:Ethers; D008738:Methyl Ethers; D012997:Solvents; C043243:methyl tert-butyl ether; D002784:Cholesterol