A low frequency (220 kHz) ultrasound system for enhancement of gallstone dissolution

A clinical system using 220 kHz broad-beam ultrasound for the dissolution of gallstones is presented. Ultrasound is applied in the transcutaneous mode and a gallstone solvent is introduced directly into the gallbladder using a uniquely designed catheter which is inserted through the skin surface to the gallbladder. Initial in vitro studies were conducted in a latex gallbladder simulation envelope containing human gallstones in appropriate solvents, with the entire system immersed in 37°C degassed water and illuminated with a broad-beam ultrasound configuration. Great acceleration was demonstrated in gallstone dissolution over that unaided by ultrasound irradiation. The system has recently been applied in the clinical arena. Animal studies have shown, in addition, the ability to produce gallbladder ablation by a change in the acoustic intensity parameter