Effects of extracorporeal shock wave lithotripsy on the structure and function of rabbit kidney.

An animal model was developed to investigate the effect of extracorporeal shock wave lithotripsy (ESWL) on a normal kidney. Rabbits were treated with 3,000 shock waves at 18 kV to each kidney. Blood and urine samples were collected daily before and after shock wave treatment. Serum levels of hemoglobin, creatinine, lactic dehydrogenase (LDH), creatinine phosphokinase (CPK), and total protein were determined. Urine determination of volume, total protein, hemoglobin, and creatinine were also made. All kidneys, after sacrifice, were subjected to histologic analysis. The average pre-treatment creatinine clearance of our rabbits was 8.3 ml./min. After the treatment, a significant (p less than 0.01) reduction in creatinine clearance was noted for four days. The reduction was to 0.61 ml./min. on day one, 0.87 on day two, 1.04 on day three, and so forth. Urine hemoglobin rose significantly (p less than 0.01) for the first three days from 0.0 to 1.5 gm./dl. Histologic examination at seven days showed focal subcapsular hemorrhage, tubular dilation, and interstitial hemorrhage. Histologic evaluation at two months revealed focal interstitial fibrosis. In conclusion, this study reveals that shock waves to the kidney have short term physiologic effects on renal function and permanent focal histologic effects, which do not effect long term physiologic function. Further research on the effects of ESWL on renal function and structure could be facilitated with the use of this model.