Basic fibroblast growth factor mediates angiogenic activity in early surgical wounds

Background. Wound angiogenesis is believed to be initiated by the early rapid release of preformed growth factors such as basic fibroblast growth factor (bFGF). However, neither the angiogenic environment of early surgical wounds nor the potential contribution of bFGF to early surgical wound angiogenesis has been investigated. Methods. We collected surgical drain fluid (SDF) from closed suction drains 6 hours to 6 days after operation. SDF was tested for endothelial cell (EC) proliferative and chemotactic activity and for the capacity to stimulate angiogenesis in vivo in the rat corneal assay. bFGF levels of SDF were determined with enzyme-linked immunosorbent assay. Neutralizing antibody to bFGF was used to determine the contribution of bFGF to SDP activity. Results. The EC proliferative activity of SDF was maximal on postoperative day 0 (POD 0, 390% that of normal serum) and then fell by 41% on POD 1 and to near serum levels thereafter. SDF from PODs 0 and 1 also showed marked EC chemotactic activity and stimulated rapid formation of new vessels without signs of inflammation when implanted into rat corneas. The temporal appearance of bFGF in these exudates showed a pattern similar to EC proliferative activity, peaking on POD 0 at 854 pg/ml and decreasing 80% by POD 2. Neutralizing antibody to bFGF decreased the proliferative activity of SDF from PODs 0 and 1 to near serum levels and substantially decreased the chemotactic and the in vivo neovascular response to SDFs. Conclusions. Surgical wounds are characterized by a rapid and early angiogenic environment that is mediated in part by bFGF, suggesting that tissue or platelet stores of bFGF may help initiate wound repair.