EFFECTS OF EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY ON RENAL GROWTH AND FUNCTION - AN ANIMAL-MODEL

The long-term effects of extracorporeal shockwave lithotripsy (SWL) on children are unclear. At 40 days of age, with an average weight of 16 6 g, 34 Wistar white rats were divided into three groups: 9 rats (cont rol group) received no shockwaves, 10 rats (Group 1) received 1000 sho ckwaves at 16.0 kV, and 15 animals (Group 2) received 1000 shockwaves at 17.2 kV. Six months later, at maturity, body weight; lithium and cr eatinine; fractional sodium, potassium, and lithium excretion; and the clearances of lithium and creatinine were measured, and the kidneys w ere studied grossly and histologically. We found no significant change s in overall animal or renal growth between the post-SWL groups and th e control group. However, there were significant changes in renal func tion, mainly in Group 2; the animals of this group presented a signifi cant increase in blood lithium and potassium, besides a significant de crease in the fractional potassium excretion compared with the control group. Furthermore, the animals in Group 2 showed permanent histologi c renal changes, including red cells in Bowman's capsule and glomerula r congestion. The disorders caused by SWL are compatible with hyporeni nemic hypoaldosteronism, an inappropriate low plasma renin activity an d aldosterone deficiency. We conclude that SWL does not affect either overall animal or renal growth but may cause permanent histologic dama ge and significant changes in renal function.