[Fragmentation of urinary calculi using the Lithoclast EMS. Technique and results].

The Lithoclast is an endoscopic lithotriptor which uses the ballistic energy produced by a small hand-held apparatus, by the movement of a small metal part (the projectile) driven by a jet of compressed air. The energy is transmitted to a metal rod whose diameter is selected according to the application: 0.8 or 1 mm in the ureter; 2 mm in the bladder and kidney. We have used this apparatus to treat 40 stones in 39 patients (25 ureteric stones, 11 renal stones, 4 bladder stones). Satisfactory fragmentation was obtained for 39 of the 40 stones (97.5%). The apparatus is very easy to use in the kidney and bladder (the risk of urinary tract perforation is very low at this level). The risk of perforation of the ureteric wall by 0.8 mm or 1 mm rods is considerable (12% of cases), but these punctate lesions heal rapidly over a double J stent. Special techniques should be used in the ureter to limit the risk of pushing the stone towards the renal pelvis.