NORMOXIC WOUND FLUID CONTAINS HIGH-LEVELS OF VASCULAR ENDOTHELIAL GROWTH-FACTOR

Objective To examine the temporal integration of vascular endothelial growth factor (VEGF), which has been shown to be present in wound flui d, with the putatively related processes of wound fluid oxygen content , wound angiogenesis, and granulation tissue formation. Summary Backgr ound Data During cutaneous wound repair, new tissue formation starts w ith reepithelialization and is followed by granulation tissue formatio n, including neutrophil and macrophage accumulation, fibroblast ingrow th, matrix deposition, and angiogenesis. Because angiogenesis and incr eased vascular permeability are characteristic features of wound heali ng, VEGF may play an important role in tissue repair. Methods A ventra l hernia, surgically created in the abdominal wail of female swine, wa s repaired using silicone sheeting and skin closure. Over time, a flui d-filled wound compartment formed, bounded by subcutaneous tissue and omentum. Ultrasonography was performed serially to examine the anatomy and dimensions of the subcutaneous tissue and wound compartment. Seri al wound fluid samples, obtained by percutaneous aspiration, were anal yzed for Po-2, Pco(2), pH, and growth factor concentrations. Results T hree independent assays demonstrate that VEGF protein is present at su bstantially elevated levels in a wound fluid associated with the forma tion of abdominal granulation tissue. However, the wound fluid is not hypoxic at any time. Serial sampling reveals that transforming growth factor beta-1 protein appears in the wound fluid before VEGF. Conclusi ons The results suggest that VEGF is a prominent regulator of wound an giogenesis and vessel permeability. A factor other than hypoxia, perha ps the earlier appearance of another growth factor, transforming growt h factor beta-1, may positively regulate VEGF appearance in the wound fluid.