Low-Energy Shockwave Therapy Improves Ischemic Kidney Microcirculation

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 beta 1-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.