Angiogenesis in Wounds Treated by Microdeformational Wound Therapy

Abstract

Summary Background Data Mechanical forces play an important role in tissue neovascularisation and are a constituent part of modern wound therapies. The mechanisms by which Vacuum Assisted Closure (VAC) modulates wound angiogenesis are still largely unknown. Objective To investigate how VAC treatment affects wound hypoxia and related profiles of angiogenic factors as well as to identify the anatomical characteristics of the resultant, newly formed vessels. Methods Wound neovascularization was evaluated by morphometric analysis of CD31- stained wound cross sections as well as by corrosion casting analysis. Wound hypoxia and mRNA expression of HIF-1α and associated angiogenic factors were evaluated by pimonidazole hydrochloride staining and quantitative RT-PCR, respectively. VEGF protein levels were determined by western blot analysis. Results VAC-treated wounds were characterized by the formation of elongated vessels aligned in parallel and consistent with physiologically function, compared to occlusive dressing control wounds that showed formation of tortuous, disoriented vessels. Moreover, VAC-treated wounds displayed a well-oxygenated wound bed, with hypoxia limited to the direct proximity of the VAC-foam interface, where higher VEGF levels were found. By contrast, occlusive dressing control wounds showed generalized hypoxia, with associated accumulation of HIF-1α and related angiogenic factors. Conclusions The combination of established gradients of hypoxia and VEGF expression along with mechanical forces exerted by VAC therapy was associated with the formation of more physiological blood vessels compared to occlusive dressing control wounds. These morphological changes are likely a necessary condition for better wound healing.

Ultrasound-guided scraping of fibrous capsule plus bilayered negative pressure wound therapy for treatment of refractory postmastectomy seroma

“…25e27 Recent studies have shown that NPWT can induce morphological and quantitative alterations in the lymph vessel network in a wound, 28 promote angiogenesis via hypoxia-inducible factor (HIF)/vascular endothelial growth factor (VEGF) signaling pathway, 29 and exert positive pressure of the wound surface. 30 In this series, we developed a novel bilayered NPWT for the postoperative treatment of refractory seroma.…”

Mechanoregulation of Angiogenesis in Wound Healing

“…5). 58 Expression of HIF-1a and VEGF in MDWT-treated wounds was decreased in comparison with control wounds, suggesting a more physiological blood flow and more effective exchange in oxygen and metabolites in MDWT. They also reported a gradient of VEGF expression closer to wound surface, correlating with the observations in human wounds by Bassetto et al, who reported concentration of angiogenic phenomena in the close vicinity to the wound-foam interface.…”

Negative Pressure Wound Therapy in the Management of Combat Wounds: A Critical Review

“…The pressure around the periphery of the wound produces relative hypoxia, which stimulates angiogenesis due to increased expression of vascular endothelial growth factor (VEGF). 29 The overall effect is reduction in size and depth of wound and formation of robust granulation tissue over exposed bone and other soft tissues. The microbial load in wound treated with NPWT is also believed to be reduced, which itself promotes wound healing.…”