Morphologic Renal Changes Following Piezoelectric Lithotripsy or Spark-Gap Lithotripsy

Abstract

Morphologic changes of the kidney following extracorporeal shock wave lithotripsy (ESWL†) have been demonstrated by magnetic resonance imaging (MRI) to be present in as many as 85% of patients treated with first-generation electrohydraulic lithotripters. In this study the renal morphologic changes produced by a second-generation piezoelectric machine (Wolf Piezolith 2300) were compared to those of an electrohydraulic lithotripter (Dornier HM3). The mean stone size was 11 mm, and the mean number of shock waves on the Wolf lithotripter was 3,900 at an average power intensity of 900 bar and on the Dornier device was 1,760 shock waves at 21 kV. All patients were studied with renal MRI scans 24 hours following lithotripsy. A subsequent MRI scan was performed at two weeks and then at one month if any changes were noted on the prior study.