Shockwave lithotripsy: dose-related effects on renal structure, hemodynamics, and tubular function.
OBJECTIVE
Shockwave lithotripsy (SWL) predictably damages renal tissue and transiently reduces function in both kidneys. This study characterized the effects on renal function of a supraclinical dose of shockwaves (SWs) (8000) in porcine kidneys and tested the hypothesis that such excessive treatment would intensify and prolong the resulting renal impairment.


METHODS
Pigs aged 6 to 7 weeks were anesthetized and assigned to one of three groups. Groups 1 (N=8) and 2 (N=6) each received 8000 SWs at 24 kV (Dornier HM3) to the lower-pole calix of one kidney. Group 3 (7 pigs) received sham treatment. Renal function was monitored for the first 4 hours after SW treatment in Group 1 and for 24 hours in Group 2. Plasma renin activity was measured in Groups 2 and 3.


RESULTS
The renal lesions produced by 8000 SWs comprised 13.8%+/-1.4% of the renal mass. In the 4-hour protocol, this injury was associated with marked reduction of the glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary sodium excretion in both kidneys, although fractional sodium excretion was reduced only in the shocked kidneys. In the 24-hour protocol, GFR and RPF remained below baseline in shocked kidneys at 24 hours. Evidence of progressive ischemic injury was noted in shocked tissue at 24 hours after SW treatment.


CONCLUSIONS
These findings support the hypothesis that the severity of the renal injury caused by SWL is related to the number of SWs administered and demonstrate the connection in this relation between renal structure and function.
Willis
Lynn R
LR
Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA. willis1@iupui.edu
Evan
Andrew P
AP
Connors
Bret A
BA
Shao
Youzhi
Y
Blomgren
Philip M
PM
Pratt
J Howard
JH
Fineberg
Naomi S
NS
Lingeman
James E
JE
D000818:Animals; D002940:Circadian Rhythm; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology / Q000528:radiation effects*; D019220:High-Energy Shock Waves; D007668:Kidney / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects*; D007684:Kidney Tubules / Q000378:metabolism / Q000528:radiation effects / Q000648:ultrastructure; D008096:Lithotripsy / Q000379:methods; D017595:Renal Plasma Flow / Q000502:physiology / Q000528:radiation effects*; D012964:Sodium / Q000652:urine; D013552:Swine
D012964:Sodium