[Intracorporeal shockwave lithotripsy using the neodymium YAG laser]

The problem of suitable energy transfer and conversion for intraureteral lithotripsy has not yet been solved satisfactorily. Laser-induced shockwave lithotripsy (LISL) appears to be a very promising solution to this problem. We report on initial clinical experience using a Q-switched Nd:YAG laser generating a shockwave on the metallic surface of an optomechanic coupler. This leads to the fine fragmentation of a urinary calculus situated close to or in contact with the coupler. Only minimal side effects occur in biological tissue. Further development of the coupler resulted in considerable increase of its fragmentation capability with no increase in side-effects. As a result, application under fluoroscopic control alone became possible, which appears adequate in approximately half of the cases. In the other half visual inspection via ureteroscopy is required. Laser-induced lithotripsy is the only technique that uses a flexible transmission system, results in the fine fragmentation of calculi, and is free of serious side effects on tissue, i.e. does not lead to perforation of the wall of the ureter.