Extracorporeal shock wave treatment improves incisional wound healing in diabetic rats

Impaired wound healing in surgical patients with diabetes increases the incidence of infection, prolongs hospitalization, and even increases the rate of mortality. Low-energy extracorporeal shock wave treatment (ESWT) was reported to accelerate chronic wound healing by promoting revascularization and tissue regeneration; however, it is not known if ESWT could also improve healing of acute surgical incisional wounds in diabetes. In this study, using a rat model of diabetes, we investigated the effect of low-energy ESWT on collagen content in wound tissues and its efficacy in incisional wound healing. A single dorsal incisional wound was inflicted in streptozotocin-induced diabetic rats, and they received ESWT at different time post-wounding. Rats were sacrificed on days 7 and 14 post-wounding. Wound breaking strength, hydroxyproline content, histological characteristics and the expression of transforming growth factor beta 1 (TGF-β1) were analyzed. As a result, the wound breaking strength was significantly enhanced and the hydroxyproline content in wound tissues was increased at each time point examined. The number of fibroblasts was signicantly increased, and the new collagen fibers were more abundant at the wound site after ESWT. Furthermore, the expression of TGF-β1 was up-regulated after ESWT on day 7 post-wounding. These results suggest that low-energy ESWT can increase collagen content, enhance wound breaking strength and improve the healing of incisional wound in diabetic rats. The increased collagen content may be attributed, at least in part, to the up-regulation of TGF-β1 expression in wound tissues.