Extracorporeal shock wave lithotripsy for renal and ureteral calculi with MPL-9000. Correlation between stone burden and shock wave energy]

Clinical results of ESWL for renal and ureteral stone with MPL-9000 were presented. We also reviewed correlation between stone burden and shock wave energy. We studied 210 cases (295 sessions) of renal stone and 109 cases (154 sessions) of ureteral stone that were treated from November 1988 till January 1989 and from November 1989 till May 1990. Of those sessions, 76 sessions of renal stone cases and 53 of ureteral stone cases were carried out ambulatorily. Successful disintegration (within 4 mm) rate was 86% of renal stones, 84% of ureteral stones, and stone free rate after 6 months was 72% of renal stones and 84% of ureteral stones. As for the complications, brain infarction occurred in one case, subcapsular hematoma of the kidney in one, and arythmia in 5. No other severe side effects were observed. Between shock wave energy (the number of shock wave shots x voltage) and stone burden (long axis x short axis of the stone), a significant correlation was found in renal stone cases, but not in ureteral stone cases. E/B (shock wave energy/stone burden) was 33,100 (kv.shots/cm2) for the renal stone and 56,000 (kv.shots/cm2) for the ureteral stone. These results suggest that there is still another unknown factor, which is not related with renal stone, for successful disintegration of ureteral stone. We also confirmed that more energy is necessary for destruction of ureteral stone than for that of renal stone.(ABSTRACT TRUNCATED AT 250 WORDS)