Renal disease potentiates the injury caused by SWL.
OBJECTIVE
The present study tested the hypothesis that renal disease potentiates the structural/functional changes induced by a clinical dose of shockwaves.


METHODS
Experimental pyelonephritis was induced in 6- to 8-week-old pigs before treatment with 2,000 shocks at 24 kV. These pigs were divided into two groups according to whether they were infected with a highly virulent (Group 1) or less virulent (Group 2) inoculation of E. coli. All animals were imaged by MR prior to SWL as a means of documenting the extent of pyelonephritis and immediately after SWL to examine the lesion produced by the shockwaves. The glomerular filtration rate (GFR), renal plasma flow (RPF) and para-aminohippurate (PAH) extraction were determined bilaterally on day 30 (Group 1) or day 80 (Group 2).


RESULTS
In group 2, urine flow and sodium excretion were reduced by 50% from baseline in the shocked kidneys at both 1 and 4 hours post-SWL. A sustained reduction in RPF through 4 hours post-SWL was noted in the shocked kidneys in Group 1, but RPF was significantly reduced only at the 1-hour determination in Group 2. Large, consistent reductions in GFR were evident at 1 and 4 hours post-SWL in shocked and unshocked kidneys of Group 2 and in the shocked kidneys of Group 1. No significant changes were noted in PAH extraction.


CONCLUSIONS
Acute pyelonephritis exaggerated the effect of a clinical dose of shockwaves on renal hemodynamics. This effect suggests that renal disease may be risk factor for SWL-induced injury.
Evan
A P
AP
Department of Anatomy, Indiana University, School of Medicine, Indianapolis 46202-5120, USA. evan@anatomy.iupui.edu
Connors
B A
BA
Pennington
D J
DJ
Blomgren
P M
PM
Lingeman
J E
JE
Fineberg
N S
NS
Willis
L R
LR
D000818:Animals; D004231:Diuresis; D004926:Escherichia coli / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology; D005919:Glomerular Filtration Rate; D007668:Kidney / Q000293:injuries* / Q000473:pathology / Q000503:physiopathology; D008096:Lithotripsy / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging; D009318:Natriuresis; D009929:Organ Size; D011704:Pyelonephritis / Q000382:microbiology / Q000503:physiopathology*; D012079:Renal Circulation; D013552:Swine