Vascular endothelial growth factor gene therapy in improvement of skin paddle survival in a rat TRAM flap model

Abstract

Abstract Introduction: Growth factors have shown potential for inducing angiogenesis and enhancing survival in the flap tissue. Targeted gene therapy has been shown to increase the bioavailability of various growth factors. In this study, we examined the effectiveness of preoperative vascular endothelial growth factor (VEGF) plasmid DNA transfection on the survival of the skin paddle in a rat pedicled TRAM flap model. Methods: Fifty-two rats were used. In part one, VEGF plasmid DNA was injected into the subcutaneous fascial layer of the upper abdominal walls of the rats. On postoperative day 4, biopsies were taken for histological review and VEGF protein quantification. In part two, the rats were divided into three groups. In the experimental group, the VEGF plasmid DNA was injected into the subcutaneous fascial layer in the area where the TRAM flap would be elevated. There were two control groups: one with plasmid containing no VEGF DNA and one with saline. The flaps were raised and examined 4 days after injection. Results: Flap tissue receiving VEGF plasmid DNA revealed angiogenesis. The VEGF level was significantly higher than of the tissue without receiving VEGF plasmid DNA injection. The mean viable area of the skin paddles receiving pre-operative VEGF plasmid DNA injection was significantly larger than that of flap receiving no VEGF plasmid DNA and saline injection. Conclusions: This study demonstrated that preoperative subcutaneous injection of VEGF plasmid DNA induced angiogenesis and improved the TRAM skin paddle survival.