Effect of Extracorporeally Induced High-Energy Shock Waves on the Rabbit Kidney and Ureter: A Morphologic and Functional Study*

Publisher Website
Google Scholar
Abstract
Since its introduction in 1980, extracorporeal shock wave lithotripsy (ESWL) has become a widely accepted noninvasive treatment modality for urinary stones. Certain guidelines for the cautious use of shock wave energy have been advocated; however, the margins of safety have not been fully outlined. We exposed the kidneys and ureters of New Zealand rabbits to extracorporeal shock wave energy. Following a unilateral nephrectomy, 15 rabbits were exposed to two sessions of 2000 shock waves at 14 kV to their kidneys, 16 animals received 1600 shock waves at 16 kV to the ureter, and 16 rabbits underwent application of 4000 shock waves at 14 kV in a single session to their kidneys. The remaining animals served as controls, and there were eight anesthesia-related deaths. Groups of rabbits were sacrificed at 2 weeks and 2 months. The treated ureters showed no pathological change. The kidneys treated with two 2000 shock wave sessions 48 hours apart revealed minimal focal tubular dilatation in 33% of cases at 2 weeks and minimal segmental cortical tubular dilatation in all animals at 2 months. The kidneys subjected to 4000 shock waves in one session showed subcapsular and cortical hemorrhage in 75% of the cases at 2 weeks; long-term specimens displayed focal and segmental fibrosis and damage to the renal parenchyma in all animals. In the rabbit model, if one adheres to the guidelines of 2000 shock waves as the upper energy limit and utilizes a treatment interval of 48 hours, ESWL is a safe procedure with minimal long-term morphologic alterations.