1991 Volume 82 Issue 3 Pages 462-466
Ninety-four kidneys with renal stones≤20mm in diameter were treated by extracorporeal shock wave litotripsy (ESWL) using a Dornier modified HM3 lithotripter and the results were compaired with those of 98 kidneys with similar size stones treated with a Dornier HM3 lithotripter. The Dornier modified HM3 lithotripter is equipped with a new type of shock wave generator with a reduced capacity for 30% less pressure peakes at the same voltage. It has an enlarged ellipsoid leading to a smaller focus and a reduced pressure per area at the shock wave entry into the skin. All treatments of modified HM3 litotripter series were performed under only intravenous analgosedation, without epidural anesthesia. The number of shock waves in the modified HM3 series ranged 900 to 6000, with the mean values of 2863±1234, which was 1.55 times as that in the Dornier HM3 series. Complete disintegration was achieved in 94 of 94 modified HM3 series kidneys and 98 of 98 kidneys of HM3 series. Complete removal of the stone was done at 72.6% in the modified HM3 series and at 70.4% in the HM3 series 3 months after ESWL. There were no severe complications in both modified HM3 series and HM3 series. Renal damage caused by ESWL was monitored by the level of urinary enzyme, N-acetyl-beta-glucosaminidase (NAG) and β2 microglobulin (β2MG) and the level of urinary protein. The levels of NAG, β2MG and urianry protein in the HM3 series were higher than those of the modified HM3 series. These results indicate that (1) a modified HM3 lithtriptor was useful for the treatment of urinary stones, and (2) renal damage seemed to be less with a modified HM3 lithotripter than with an HM3 litotripter.