Extracorporeal lithotripsy using the HM3 Dornier lithotriptor and the modified HM3 lithotriptor

Extracorporeal shock waves lithotripsy is a well established procedure for the treatment of renal and ureteral calculi. From January 1985 to December 1987, 1034 patients underwent 1152 treatments with the Dornier HM3 lithotripter; from January 1988 and December 1988, 466 patients underwent 566 treatments with the modified Dornier HM3. Treatments with the original HM3 were performed mainly under general anaesthesia (97%). Only 2.4% of modified Dornier HM3 treatments have been performed under general anaesthesia; the 97.6% were treated under a combination of anxiolytic and analgesic drugs. An average of 1900 and 2300 shock waves was applied with the original HM3 and the modified one, respectively. The rate of secondary treatment increased from 10.3% to 17.4% respectively. At three month follow-up the 85.6% of the patients treated with the original HM3 and the 76.7% of those treated with the modified Dornier were free from stones. Low energy lithotripsy with the modified semi ellipsoid has proved to be equally effective as the older generators working with high shock wave pressure.