THE EFFECT OF EXTRACORPOREAL ELECTROMAGNETIC SHOCK-WAVES ON THE MORPHOLOGY AND CONTRACTILITY OF RABBIT URETER

Purpose: Although extracorporeal shock wave lithotripsy (ESWL) is know n to cause pathologic changes in various organs, little is known about its effects on the ureter, the target organ in ESWL of ureteral stone s in situ. In this study, we sought to determine the short-term effect s of ESWL on the ureter. Materials and Methods: Left lower ureteral se gments of 21 rabbits were removed to serve as the control group and 20 00 shocks were applied to the right lower ureters. Groups of 7 rabbits were sacrificed 1, 3 and 5 days after shock wave exposure. While hist omorphological alterations were examined under light and transmission electron microscopy, contractility of all ureters was determined in or gan baths. Results: The epithelial cells disclosed no change after sho ck wave application. Histologically the muscular layer was the most af fected part of the ureter. There was interstitial and intracellular ed ema on light microscopy and marked chromatin and mitochondrial changes at the subcellular level. The adventitial layer was also edematous. T hese changes were prominent on days 1 and 3 and returned to normal on day 5. The contractility of the ureters on day 1 was significantly red uced (p <0.05). However, the contractility of the samples on days 3 an d 5 were not significantly different from controls. Conclusion: Our fi ndings demonstrate that electromagnetic shock waves produce reversible morphological and functional changes in rabbit ureteric muscle.