[Lithotripsy by ultrashort pulsation. Experimental study in renal lithiasis in the dog].

A lithotriptor delivering ultrashort shockwaves and designed for use under ultrasonographic guidance has recently been developed. Immersion in water is unnecessary. The device was experimented in renal lithiasis in dogs. Twenty-two animals were treated. In seven, who served as controls, the safety of shots delivered in particular to the lungs, liver, bones and kidneys was demonstrated. Furthermore, no cardiac rhythm disorders were recorded. A human stone was implanted in 15 animals. The stone was successfully broken up in 12. Gross and microscopic examinations done 2 to 30 days after the treatment indicate that the shots initially produce lesions similar to a limited contusion. Healing of the contusion, already underway on the 8th day, is complete by the 4th week. Elimination of the fragments is gradual. The quality of fragmentation can be evaluated during the treatment session using mode A ultrasonography. These experimental data are evidence of the effectiveness of this second generation lithotriptor.