Objective To research the effects of vascular endothelial growth factor (VEGF) on the survival of reverse flow axial skin flaps. Methods A 8 cm×2 cm full thickness transverse dorsal flap based on right deep circumflex iliacartery was elevated in 20 SpragueDawley rats, which length crossing midline was 4.0 cm. The rats were randomized into two groups:experimental group (n=10), subcutaneous VEGF injections into the flap (200 ng, 200 μl) after flap elevation; controlgroup (n=10), subcutaneous saline injections into the flap (200 μl) after flap elevation. The flap was immediately sutured to its recipient beds then the injection was executed. Seven days after operation, the survival area of flaps and density of vessels were observed and measured, meanwhile its histological representation of the flaps was examined. Results After 7 days of recovery, the mean survival area of flaps was 15.55±0.27 cm2 in experimental group and 13.42±0.57 cm2 in control group. The difference was significant between experimental group and control group (P＜0.01). The mean vessel density of flaps was 21.00±3.16 in control group and 34.40±3.75 in experimental group. The difference was significant between experimental group and control group (P＜0.01). Histological analysis demonstrated that a qualitatively greater amount of granulation tissue, regular collagen fiber and a lot of fibrillated cells were observed in experimental group. Erythrocytes were leaked outfrom vessels, and inflammatory cells were observed around in control group. Conclusion In early survival of flaps, the VEGF can improve the survival of areverse flow axial skin flap through improving angiogenesis and increasing the perfusion of vessel. It is an effective method of improving the survival of reverse flow axial skin flaps that VEGF is fully injected in subcutaneous flaps by single, when flaps are elevated.
Objective To investigate the basic mechanism of venous flow in reverseflow island flap. Methods Recent relevant literature on the mechanism of venous reverse flow in reverseflow island flap wereextensively reviewed. Results The mechanism of venous reverse flow was a multifactorial phenomenon. “Communicating and collateral by pass route” and “incompetent valve route” were two theories. Conclusion The two routes of venous reverse flow in reverse-flow island flap coexistand complement each other.