Ultrasonic lithotriptor for urethral and bladder stones.

Bladder or urethral calculi in 50 patients were effectively fragmented and removed per-urethrally using an ultrasonic lithotriptor with the probe vibrating at 30,000 implulses/s. In adults, local anaesthesia was employed and the operation performed as an out-patient procedure. The method has the advantages over others discussed in that a small (23 F) sheath is used and that damage to the bladder or urethra by the probe is avoided. Using a newer, modified sheath resembling that for punch prostatectomy, larger stones can be fragmented by engaging the stone in the fenestrum of the sheath.