GALLSTONE DISSOLUTION INVITRO USING METHYL TERT-BUTYL ETHER - RADIOLOGIC SELECTION CRITERIA

Methyl tert-butyl ether dissolves cholesterol gallbladder stones when infused through a percutaneous transhepatic catheter. All gallstones, however, contain noncholesterol components that are insoluble in lipid solvents and may be too large to be aspirated through a small catheter or flushed from the gallbladder. To identify which patients have gallstones that are most likely to completely dissolve, we evaluated the ability of methyl tert-butyl ether to dissolve gallstones in vitro based on their radiodensity and size. Radiodensity influenced completeness of dissolution (p < 0.01), but size did not (p 〉 0.5). Twenty-six of 32 radiolucent stones (81%) dissolved completely, leaving residual debris <2 mm in diameter. Only 2 of 32 radiopaque stones (6%) dissolved completely. Insoluble radiolucent and radiopaque stones <0.5 cm in diameter were black pigment stones. Four radiolucent and 19 of 22 radiopaque stones (86%) 〉0.5 cm in diameter underwent partial dissolution leaving residual debris 2 mm or larger. By infrared spectroscopy, calcium bilirubinate and calcium carbonate were identified as the principal components of this methyl tert-butyl ether-insoluble debris. Until methods for dissolving or fragmenting noncholesterol components of gallstones are available, only patients with radiolucent gallstones should be treated with methyl tert-butyl ether. © 1990, American Gastroenterological Association. All rights reserved.