title: In vitro evaluation of gallstone dissolution with methyl-tert-butyl ether and ultrasound energy.
abstract: Given the large number of cholecystectomies performed annually, a nonsurgical approach to gallstone therapy is of great interest. A laboratory ultrasound system has been developed to study enhancement of methyl-tert-butyl ether (MTBE) dissolution of human gallstones in vitro. A mathematical model that quantitatively characterizes the dissolution process via a rate constant has been developed. Using this model, the kinetics of 15 gallstones from a single patient were evaluated for three dissolution methods: 1) unstirred MTBE, 2) aspirated MTBE, and 3) ultrasonically enhanced MTBE. The results showed excellent fits between the model and measured dissolution rates. 195 kHz continuous-wave (CW) ultrasonically enhanced dissolution rates exhibited a 6.2 fold gain over the manually aspirated MTBE and a 49.5 fold gain over static MTBE dissolution. Investigation of 50% duty cycle pulsed mode ultrasound revealed that total power appears to be the determinant of the observed dissolution rates. Gallstone calcification showed a strong correlation with dissolution rates measured by the model.
authors.affiliation: Ontario Cancer Institute, University of Toronto, Canada.
authors.forename: C A
authors.initials: CA
authors.lastname: McKinley
authors.forename: J W
authors.initials: JW
authors.lastname: Hunt
authors.forename: J
authors.initials: J
authors.lastname: Ricketts
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
mesh_terms: D002769:Cholelithiasis / Q000188:drug therapy / Q000628:therapy*; D003131:Combined Modality Therapy; D004987:Ethers / Q000627:therapeutic use*; D005069:Evaluation Studies as Topic; D006801:Humans; D066298:In Vitro Techniques; D008738:Methyl Ethers; D012997:Solvents / Q000627:therapeutic use; D014464:Ultrasonic Therapy
chemical_list: D004987:Ethers; D008738:Methyl Ethers; D012997:Solvents; C043243:methyl tert-butyl ether