Evaluating Revascularization and Flap Survival Using Vascular Endothelial Growth Factor in an Irradiated Rat Model

Abstract

To evaluate the role of vascular endothelial growth factor (VEGF) plasmid DNA (pDNA) in improving flap revascularization in a previously developed rat model. Our hypothesis was that the uptake and expression of VEGF pDNA in the wound bed would improve revascularization and flap viability. Twenty-eight male Sprague-Dawley rats received a total dose of 40 Gy electron beam radiation to the ventral abdominal wall. After a recovery period, they underwent a ventral fasciocutaneous flap procedure with a 2-hour ischemia period. Group 1 (n = 14) received topical VEGF pDNA, in vivo cationic polymer, and fibrin sealant. Group 2 (n = 14) received topical cationic polymer and fibrin sealant only. Seven of the rats from each group underwent pedicle ligation at 8 or 14 days. The primary outcome measure was percentage of flap revascularization 5 days after pedicle ligation. Rats receiving VEGF pDNA had a significantly higher rate of flap revascularization (90.8% vs 79.8%) after pedicle ligation at 14 days (P = .045). At 8 days, rats receiving VEGF pDNA (group 1) had an increased rate of flap revascularization (58.2% vs 42.8%) that approached significance (P = .11). This study demonstrates the potential of VEGF pDNA to improve revascularization and flap viability in previously irradiated tissue.