Gallstones: fragmentation with a tunable dye laser and dissolution with methyl tert-butyl ether in vitro

The authors tested whether gallstone fragmentation with a tunable dye laser would speed dissolution with methyl tert-butyl ether (MTBE) and allow successful in vitro dissolution of calcified stones. Twelve sets of three stones matched for size and weight were obtained from 11 surgically resected human gallbladders and one common bile duct operation. Computed tomography was used to determine presence and distribution of calcium. One stone from each set was either chemically analyzed, mechanically fragmented with the laser, or left intact. Fragmented and intact stones were subjected to MTBE dissolution for 12 hours or until fragments were 2 mm or less in diameter. All five laser-treated, noncalcified gallstones dissolved completely, compared with four of five intact stones. All six laser-treated, calcified gallstones dissolved completely, compared with only one of six intact stones. The solitary calcified common bile duct stone, whether fragmented or intact, did not completely dissolve. Speed of dissolution was significantly faster for laser-treated stones (P = .04). The authors conclude that laser fragmentation of gallstones increases the speed of subsequent MTBE dissolution and allows successful dissolution of calcified gallstones.