The effects on the human kidney parenchyma of high-energy shockwaves (
HESW) with different energy densities were examined, Kidneys of patien
ts treated by radical nephrectomy for renal cell carcinoma were perfus
ed with cold HTK solution immediately after nephrectomy and kept in hy
pothermia (8 degrees C) for a maximum of 4 hours, The tumor-free paren
chyma was treated with 2000 shocks at energy outputs of 15 kV (16 MPa,
0.15 mJ/mm(2)), 17 kV (32 MPa, 0.25 mJ/mm(2)), 19 kV (50 MPa, 0.4 mJ/
mm(2)), and 21 kV (65 MPa, 0.6 mJ/mm(2)) in an experimental electromag
netic shockwave system (Siemens Co., Erlanger, Germany), Resulting tis
sue effects were analyzed by histologic and immunohistochemical examin
ations and confocal laser scanning microscopy, Different sensitivities
of cell components, blood vessels, and tubules were found. Laser scan
ning microscopy revealed nuclear alterations in the vicinity of the fo
cus up to a distance of approximately 10 mm, Severe histologic changes
were found in a smaller zone, while immunohistochemistry studies reve
aled negative collagen IV staining in an area of approximately 4 x 4 m
m (all distances measured within the plane perpendicular to the acoust
ic axis), From these results, it can be concluded that HESW directly d
amage the tubules and the vascular system, which might explain the cli
nical changes after extracorporeal shockwave lithotripsy in human pati
ents, The extent of these effects seems to be dependent on the applied
energy.