[Tissue damage during percutaneous ultrasonic lithotripsy]

The ultrasound lithotripsy for the percutaneous desintegration of renal calculi does not cause any irreversible injuries. The intensity of the ultrasound lithotriptor is clearly below the cavitation threshold. By aspiration the ultrasound probe injures the mucous membrane. A superficial oedema and submucous haemorrhages appear. Despite an amplitude of 50 mu no perforation could be obtained at the urinary bladder of the rabbit. In irrigation of the ultrasound probe with more than 20 ml disinfectant per minute a tissue-injuring heat development is prevented. In the Sister-chromatide-exchange test no mutagenic effect by influence of the ultrasound could be proved. Metal splinters are excreted with the urine. Infolded into the wall of the urinary bladder they are unchangedly to be proved after nine weeks, in contrast to the suture the histological reaction is, however, minimal.