Gene therapy with adenovirus-mediated VEGF enhances skin flap prefabrication

We investigated the feasibility in rats of enhancing skin‐flap prefabrication with subdermal injections of adenovirus‐encoding vascular endothelial growth factor (Ad‐VEGF). The left saphenous vascular pedicle was used as a source for vascular induction. A peninsular abdominal flap (8 × 8 cm) was elevated as distally based, keeping the epigastric vessels intact on both sides. After the vascular pedicle was tacked underneath the abdominal flap, 34 rats were randomly divided into three groups according to treatment protocol. The implantation site around the pedicle was injected with Ad‐VEGF in group I (n = 10), with adenovirus‐encoding green fluorescent protein (Ad‐GFP) in control group I (n = 14), and with saline in control group II (n = 10). All injections were given subdermally at four points around the implanted vessel by an individual blinded to the treatment protocol. The peninsular flap was sutured in its place, and 4 weeks later, an abdominal island flap based solely on the implanted vessels was elevated. The prefabricated island flap was sutured back, and flap viability was evaluated on day 7. Skin specimens were stained with hematoxylin and eosin for histological evaluation. In two rats from each group, microangiography was performed to visualize the vascularity of the prefabricated flaps. There was a significant increase in survival of prefabricated flaps in the Ad‐VEGF group compared to the control groups: Ad‐VEGF, 88.9 ± 6.1% vs. Ad‐GFP, 65.6 ± 9.4% (P