RESUMO
BACKGROUND: The transverse rectus abdominis musculocutaneous (TRAM) flap may develop necrosis, especially in patients with risk factors such as previous abdominoplasty, caused by damage to perforating vessels during surgical procedures. This study was designed from the perspective of using vascular endothelial growth factor (VEGF) gene therapy with plasmid vector after abdominoplasty to stimulate neovascularization of the TRAM flap, thus increasing flap viability. METHODS: Thirty-two Wistar rats were divided into four groups (n = 8). A right inferiorly based TRAM flap was constructed in all animals and was the only procedure performed in group I (TRAM flap). Animals from groups II (abdominoplasty) and III (plasmid) underwent abdominoplasty and were injected intramuscularly with physiologic saline solution and empty plasmid, respectively. Group IV (VEGF) received intramuscular injection of naked plasmid DNA encoding VEGF-165 during abdominoplasty. The TRAM flap was created 30 days after abdominoplasty. RESULTS: The mean necrosis was 24.65 +/- 18.13 percent in group I, 62.49 +/- 28.06 percent in group II, 57.80 +/- 25.43 percent in group III, and 18.33 +/- 16.20 percent in group IV. The number of vessels in the TRAM flap was determined by immunohistochemistry using the antibody human heart factor. Groups I and IV had a similar number of vessels, as did groups II and III. Groups I and IV had greater viability and number of vessels than groups II and III. CONCLUSION: VEGF gene therapy increased viability and vessel number in the TRAM flap created after abdominoplasty in a rat model.