Absence of long-term gonadotoxicity in primates receiving extracorporeal shock wave application

Extracorporeal shock wave lithotripsy (SWL) is becoming popular in the management of lower ureteral calculi; however, the quantity of data on its potential gonadotoxic effects are limited. Eight nonhuman primates had baseline measurements of testicular volume, semen analysis, serum testosterone and FSH assays, and DNA flow cytometric analysis of testicular aspirates. The anesthetized primates were lowered into a Dornier XL-1 lithotripter and at a 20 kV power setting had various numbers of shocks (0, 500, 1500) directed at each testis. Sequential studies were done at 6-week intervals for 9 months. The control group showed no significant change in any measure. Semen analysis, testosterone, and FSH results were variable and without statistically significant differences. There were changes in the DNA histograms, with the tetraploid (4N) group of cells being the most sensitive. All changes caused by SWL application returned to baseline by 9 months. Data from this primate study document no apparent long-term male gonadotoxicity from SWL, but the authors suggest measures to protect the testis during clinical use.