[Clinical treatment of urinary tract stones with Alexandrite laser].

Clinical treatment of urolithiasis with Alexandrite-laser which is a solid pulse laser system developed in Switzerland is reported. Two cases of renal stones, 3 cases of vesical stones, and 35 renal units in 34 cases of ureteral stones were treated. The approach to the aimed stone was, percutaneous to the renal stones, and transurethral to the vesical and ureteral stones. The clinical success rate was 92.5% (37/40), when we defined success as the endoscopically observed fragmentation. The uric acid stone in the bladder was not disintegrated even when the plasma occurred, but the ureteral uric acid stone was easily fragmented. The difference was thought to be attributed to the condition of the surface. The Alexandrite-laser system generates a 750 nm wavelength, and this wavelength is neither absorbed in water nor hemoglobin, so is thought to be harmless to the tissue. Actually, if misirradiation to the ureteral mucosa during lithotripsy was done, neither plasma formation nor perforation occurred. In conclusion, the Alexandrite-laser is thought to be safe and effective equipment for the treatment of urolithiasis.