Background: Because direct application of low-energy shock waves induces angiogenesis, we investigated the safety and efficacy of this new therapy to develop a noninvasive method of repeatable therapeutic angiogenesis for treating peripheral arterial disease (PAD).
Subjects and Methods: The subjects were 10 patients who had symptomatic PAD and limited ischemia in a below-the-knee artery. Low-energy shock waves were directly applied to the calf muscles 6 times every other day. Intracorporeal changes were evaluated with ultrasonography to determine adverse effects of therapy. To assess blood flow of the microcirculation, transcutaneous oxygen tension (TcPO₂), skin perfusion pressure (SPP), and ^99mtechnetium-tetrofosmin (^99mTc-TF) scintigraphy were performed before and after therapy. The TcPO₂ was measured while subjects inhaled pure oxygen (maximum TcPO₂). The ^99mTc-TF perfusion index was determined as a ratio of uptake in muscle to that in the brain (control) for quantitative analysis.
Results: No adverse effects were noted in any patient. Maximum TcPO₂ values increased significantly on the calf (57.3±28.4 to 71.0±14.5 mm Hg, p=0.044) and the dorsum of the foot (52.2±21.8 to 76.1±17.9 mm Hg, p=0.012). The SPP tended to increase after therapy on the dorsum and plantar surfaces of the foot, but the differences were not significant. The ^99mTc-TF perfusion index in the foot significantly increased (0.48±0.09 to 0.61±0.12, p=0.0013), but that in the leg did not change.
Conclusion: We have demonstrated that low-energy shock wave therapy is safe and can restore blood flow in the microcirculation in patients with symptomatic PAD.