[MTBE litholysis and extracorporeal shock wave lithotripsy of gallstones]

Two new therapies for cholesterol gallstones, MTBE litholysis and extracorporeal shock-wave lithotripsy, have been developed and clinically tested in the last five years. In principle MTBE litholysis is applicable in 50-80% of gallstone patients and shock-wave lithotripsy in 25-30%. In MTBE litholysis a pigtail catheter is placed in the gallbladder by the percutaneous-transhepatic route using ultrasound-guidance. The gallstones can than be dissolved with the cholesterol contact solvent MTBE (methyl tert-butyl ether). With appropriate selection criteria the successful dissolution rate is 80-90%. Over 99% of radiolucent gallstones (1-3 stones per gallbladder) can be fragmented by extracorporeal shockwaves. Bile acids must be administered as adjuvant litholytic therapy, and thus the remaining fragments can be dissolved in 91% of cases within 2-18 months. In view of the limited experience with these procedures at the present time they are mainly indicated for symptomatic surgical high-risk patients and for those who strongly wish to avoid surgery. With careful evaluation of study data a broader indication policy may be possible in the future. The new methods and the essential study data are presented.