In vitro Cholesterol Gallstone Dissolution after Fragmentation with Shock Waves

In order to test whether shock wave fragmentation of human gallstones increases their dissolution rates in a bile acid-lecithin solution, we carried out in vitro experiments. Stones comparable in size, weight and cholesterol content (86%) from the same human gallbladder were disintegrated by shock waves. A glycoursodeoxycholic acid (GUDC)-lecithin solution served as solvent. After 10 days incubation in this solvent, intact stones had lost only 4% of their cholesterol. This value increased to 92% after disintegration of the stones by 300 shock wave discharges. Fragments with a size of less than 2 mm had lost 55% of their cholesterol after day 1 and 99% after day 10. A large stone fragment cleaved off by shock waves lost much more cholesterol (42% after 10 days) than an intact untreated stone (4% after 10 days) comparable in size, weight and cholesterol content. These data show that shock wave lithotripsy of cholesterol gallstones considerably accelerates their dissolution rate in a GUDC-lecithin solvent, the desirable fragment size being 2 mm or less. However, even large fragments may lose much more cholesterol than comparable intact stones as a result of changes in surface structure as documented by scanning electron microscopy. The experiments favor the concept of a combined treatment of gallbladder stones by extracorporeally generated shock waves and bile salt therapy.