血管内皮生长因子促进跨区供血反流轴型皮瓣成活的实验研究

目的研究血管内皮生长因子（vascular endothelial growth factor，VEGF）的局部皮下注射对大鼠背部跨区供血反流轴型皮瓣成活的影响及效果。方法取20只SD大鼠，制备8cm×2cm大鼠背部跨区供血反流轴型皮瓣模型，随机分成两组，每组10只。实验组：于皮瓣远端7．5cm及6．5cm处共选择4个对称位点，分别予100ng／100μlVEGF溶液50μl；对照组：每一位点予生理盐水50μl。术后1～7d行皮瓣大体观察，并于7d处死大鼠，切取皮瓣，行皮瓣成活率测定、组织学观察及血管密度检测。结果大体观察，实验组皮瓣成活面积明显大于对照组，实验组皮瓣成活面积15．55±0．27cm^2，对照组13．42±0．57cm^2，差异有统计学意义（P〈0.01）。组织学观察，实验组皮瓣血管密度34．40±3．75个／10倍光镜下视野，对照组21．00±3．16个／10倍光镜下视野，差异有统计学意义（P〈0.01）。镜下见实验组有大量新生肉芽组织形成，胶原纤维排列规则，成纤维细胞较多，炎性细胞浸润程度轻；对照组新生肉芽组织少，胶原纤维凝集成块，成纤维细胞少，炎性细胞浸润程度重。结论VEGF在皮瓣成活早期，通过促进缺血皮瓣新生血管形成，增加血管数量，改善缺血组织的血液供应，促进皮瓣成活；在皮瓣形成时局部、单次、足量应用VEGF是促进跨区供血反流轴型皮瓣远端成活的有效方法。

THE EFFECTS OF VASCULAR ENDOTHELIAL GROWTH FACTOR ON SURVIVAL OF REVERSE FLOW AXIAL SKIN FLAPS

OBJECTIVE: To research the effects of vascular endothelial growth factor (VEGF) on the survival of reverse flow axial skin flaps. METHODS: A 8 cm x 2 cm full thickness transverse dorsal flap based on right deep circumflex iliac artery was elevated in 20 Sprague-Dawley 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 microl) after flap elevation; control group (n = 10), subcutaneous saline injections into the flap (200 microl) 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 out from vessels, and inflammatory cells were observed around in control group. CONCLUSION: In early survival of flaps, the VEGF can improve the survival of a reverse 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.