THE ISOLATED-PERFUSED KIDNEY OF THE PIG - NEW MODEL TO EVALUATE SHOCKWAVE-INDUCED LESIONS

Little is known about the mechanisms and determining factors of shock wave-induced kidney trauma. After classification of the renal lesion i n a canine model, we attempted to establish an ex vivo model using the isolated kidney of the pig perfused by Tyrode's solution under physio logic conditions. After shock wave application on the Modulith SL 20, vessel lesions were evaluated by microangiography to determine the siz e and frequency of dye extravasation in the different areas of the org an. Variation of the focus localization caused different patterns of l esions that characterized the pathway of the shock wave. In particular , constant petechial extravasation in the cortex was observed. The gen erator voltage correlated with the diameter and the frequency of the l esion area. The number of shock waves primarily affected the incidence of vessel rupture in the regions adjacent to the focal zone. Light mi croscopy revealed dose-dependent necrosis of tubular cells up to gap-l ike parenchymal defects. Even after application of the minimal shock w ave doses, electron microscopy demonstrated vacuolization of tubular c ells in the shock wave focus. Traumatic junctions between capillaries and the tubulur system can explain clinically observed macrohematuria without renal hematomas. With this model, it was possible to evaluate localization and dose dependence of shock wave-induced kidney trauma w ith high sensitivity and reproducibility. Further advantages of the mo del were easy availability and the fact that studies on living animals were not necessary. Therefore, standardization and comparison of diff erent lithotripters becomes possible.