Clark DL et al, 2011: Pretreatment with low-energy shock waves reduces the renal oxidative stress and inflammation caused by high-energy shock wave lithotripsy
Clark DL, Connors BA, Handa RK, Evan AP.
Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS 510, Indianapolis, IN, 46202, USA.
The purpose of this study was to determine if pretreatment of porcine kidneys with low-energy shock waves (SWs) prior to delivery of a clinical dose of 2,000 SWs reduces or prevents shock wave lithotripsy (SWL)-induced acute oxidative stress and inflammation in the treated kidney. Pigs (7-8 weeks old) received 2,000 SWs at 24 kV (120 SW/min) with or without pretreatment with 100 SWs at 12 kV/2 Hz to the lower pole calyx of one kidney using the HM3. Four hours post-treatment, selected samples of renal tissue were frozen for analysis of cytokine, interleukin-6 (IL-6), and stress response protein, heme oxygenase-1 (HO-1). Urine samples were taken before and after treatment for analysis of tumor necrosis factor-α (TNF-α). Treatment with 2,000 SWs with or without pretreatment caused a statistically significant elevation of HO-1 and IL-6 in the renal medulla localized to the focal zone of the lithotripter. However, the increase in HO-1 and IL-6 was significantly reduced using the pretreatment protocol compared to no pretreatment. Urinary excretion of TNF-α increased significantly (p < 0.05) from baseline for pigs receiving 2,000 SWs alone; however, this effect was completely abolished with the pretreatment protocol. We conclude that pretreatment of the kidney with a low dose of low-energy SWs prior to delivery of a clinical dose of SWs reduces, but does not completely prevent, SWL-induced acute renal oxidative stress and inflammation.
Urol Res. 2011 Dec;39(6):437-42. doi: 10.1007/s00240-011-0372-z. Epub 2011 Mar 9
PMID: 21387182 [PubMed - as supplied by publisher]. FREE ARTICLE
The authors have carried out an animal experiment in order to elucidate the effects of ESWL on oxidative stress. The significantly reduced concentrations of heme oxygenase-1, interleukin-6 and tumor necrosis factor-α give support to the value of a low-energy pre-treatment of the kidney before normal therapeutic shockwave power is applied.
In these experiments a 3 min pause also was included according to the authors’ previous experience of the protective value of such a step. The animals were, however, subjected to shock wave frequency of 120 per min (2 Hz), a frequency that is known to be associated with more tissue trauma than that seen with lower frequencies. Therefore it cannot be excluded that the small oxidative stress - that was recorded also in those animals for which the pre-treatment regimen had been followed - would have been further reduced or eliminated. It is possible that the more obvious signs of oxidative stress in animals without pre-treatment had been lower with a slower rate of shockwave delivery.
The results are, however, convincing and highly interesting and it seems reasonable to include a pre-treatment routine in clinical ESWL directed towards renal tissue. I have personally applied such a protocol during several years. This might be of particular importance in patients who can be assumed to require repeated treatment sessions.