Morphological Changes in Canine Kidneys Following Extracorporeal Shock Wave Treatment

Abstract

Extracorporeal shock wave lithotripsy (ESWL) has rapidly become established worldwide as a routine method for the treatment of nephrolithiasis and ureterolithiasis. Although initial studies showed no damaging effects on tissue by the shock waves, this animal study using canine kidneys demonstrated that the ESWL-induced damage to the renal parenchyma is more marked than originally assumed. This parenchymal damage probably is also the cause of the macrohematuria that is always observed during therapy. The damage is limited to the area that the shock wave was focused on, and heals relatively rapidly by connective tissue encapsulation with final cicatrization. Residual effects are only now being observed. The resulting tissue damage is not extensive enough to cause demonstrable reduction of renal function as measured by the usual methods (serum creatinine, creatinine clearance, isotope renography, intravenous urography). The complication which causes the most concern clinically is the large subcapsular hematoma which, according to present knowledge, could well result from a lesion of the larger peripheral vessels. In addition, damage to other organs such as subserous colonic and small bowel hematoma are to be expected although they do not lead to clinical symptoms.