Biological Effects Produced by High-Energy Shock Waves

Abstract

High-energy shock waves are known to produce a wide range of bioeffects associated with their clinical applications. In shock wave lithotripsy (SWL), which is the most successful application of shock waves in clinical medicine for noninvasive disintegration of kidney and upper urinary stones, transient hematuria, hematoma, and temporary deterioration of renal function may be produced. These short-term side effects in the kidney usually disappear in a few days or weeks without leading to serious long-term complications. However, there are continued efforts to investigate and understand the relationship between shock wave exposure and potential chronic adverse effects, such as new onset of hypertension and diabetes mellitus (DM). In particular, it has been advocated that high-energy shock waves should be administered judiciously to elderly and pediatric patients who are at higher risk for shock-wave-induced adverse effects than are young adult patients. Besides SWL, bioeffects produced by high-energy shock waves have been harnessed and exploited for the treatment of a variety of non-urological diseases. Shock wave therapy has been used extensively to promote bone fracture healing, pain alleviation for conditions such as epicondylitis, and the healing of chronic ulcers. Although the effectiveness and efficacy of these treatments still need to be fully validated, numerous studies have suggested that shock waves can stimulate healing through promotion of both osteogenic and angiogenic pathways. In addition, new avenues of applications are emerging as the feasibility of using shock waves for transient permeabilization of cell membrane has been demonstrated, suggesting the possibility of shock wave-targeted, noninvasive drug and gene delivery to internal organs.