Zhang X et al, 2016: Low-Energy Shockwave Therapy Improves Ischemic Kidney Microcirculation.
Zhang X, Krier JD, Amador Carrascal C, Greenleaf JF, Ebrahimi B, Hedayat AF, Textor SC, Lerman A, Lerman LO.
Division of Nephrology and Hypertension and.
Departments of Physiology and Biomedical Engineering and.
Cardiology, Mayo Clinic, Rochester, Minnesota.
Division of Nephrology and Hypertension and Cardiology, Mayo Clinic, Rochester, Minnesota.
Abstract
Microvascular rarefaction distal to renal artery stenosis is linked to renal dysfunction and poor outcomes. Low-energy shockwave therapy stimulates angiogenesis, but the effect on the kidney microvasculature is unknown. We hypothesized that low-energy shockwave therapy would restore the microcirculation and alleviate renal dysfunction in renovascular disease. Normal pigs and pigs subjected to 3 weeks of renal artery stenosis were treated with six sessions of low-energy shockwave (biweekly for 3 consecutive weeks) or left untreated. We assessed BP, urinary protein, stenotic renal blood flow, GFR, microvascular structure, and oxygenation in vivo 4 weeks after completion of treatment, and then, we assessed expression of angiogenic factors and mechanotransducers (focal adhesion kinase and β1-integrin) ex vivo A 3-week low-energy shockwave regimen attenuated renovascular hypertension, normalized stenotic kidney microvascular density and oxygenation, stabilized function, and alleviated fibrosis in pigs subjected to renal artery stenosis. These effects associated with elevated renal expression of angiogenic factors and mechanotransducers, particularly in proximal tubular cells. In additional pigs with prolonged (6 weeks) renal artery stenosis, shockwave therapy also decreased BP and improved GFR, microvascular density, and oxygenation in the stenotic kidney. This shockwave regimen did not cause detectable kidney injury in normal pigs. In conclusion, low-energy shockwave therapy improves stenotic kidney function, likely in part by mechanotransduction-mediated expression of angiogenic factors in proximal tubular cells, and it may ameliorate renovascular hypertension. Low-energy shockwave therapy may serve as a novel noninvasive intervention in the management of renovascular disease.
J Am Soc Nephrol. 2016 Jun 13. pii: ASN.2015060704. [Epub ahead of print]. FREE ARTICLE
Comments 1
Highly interesting animal report on the use of low-energy shockwave therapy (L-SWT) in pigs with or without experimentally induced micro-vascular abnormalities and renal dysfunction. The details of this study that should be obtained by reading the article, indicate that SWs might have a wide indication by improving the microcirculation in the kidney (and perhaps also in other tissues in which the circulation is impaired). The effect by L- SWT therapy might improve the circulation at least when the ischemic period has not been too long.
The bottom-line was that that following L-SWT during a period of 3 weeks the micro-circulation was improved by stimulated expression of angiogenic factors. No signs of injury were observed as a result of L-SWT.
The energy level of L-SWT corresponds to approximately 10% of that normally used for stone disintegration.
These observations are of great interest for enlarged indications for SWs in a future perspective, particularly by ameliorating renovascular disease/ hypertension as a consequence of stenotic blood-flow.
The physiology of reduced renal blood flow is summarized below:
With 6 L-SWT session during 3 weeks it was concluded that at least part of the improvement of the function of proximal tubular cells was explained by the expression of angiogenic factors (VEGF).