Vourtsis Spyridon A, Spyriounis Petros K, Agrogiannis George D, Ionac Mihai, Papalois Apostolos E
Department of Plastic and Reconstructive Surgery, 401 Military Hospital, Athens, Greece.
J Invest Surg. 2012 Feb;25(1):14-9. doi: 10.3109/08941939.2011.593693.
Induction of angiogenesis has been shown to be mediated by a number of glycoproteins called growth factors. Growth factors control the growth, differentiation, and metabolism of cells. Vascular endothelial growth factor (VEGF) is believed to be the most potent regulator of this process. The effect of its exogenous administration on the distal third of a long random skin flap was examined.
Eighteen Wistar rats were divided into two groups of nine. Rats were anesthetized, and a skin flap, measuring 1.5 × 7.5 cm, was elevated at their dorsum. The flap was standardized by centering the pedicle between the lower angles of the scapulae and by using a frame with the previously mentioned dimensions. The length of the flap was five times greater than its width. In group A (n = 9), the flap was elevated, one milliliter of normal saline was injected subdermally, at the distal third, and it was sutured back at its original place. In group B (n = 9), the flap was elevated, injections of 10 μg of VEGF were administrated subdermally, at the distal third, and it was again sutured back. Rats were euthanized a week later and flaps were excised. All specimens were measured, photographed, put in formalin 10%, and were sent for image and histological analysis. Image analysis was used both for the estimation of viable area and for the calculation of mean vessel density per mm2.
Necrotic areas of the flaps were clearly demarcated within a week's time. In group A, the mean flap survival percentage was 38.9%. In group B, the percentage was 80.4%. Histological analysis demonstrated angiogenesis in group B, with mean vessel density per mm2 being higher in group B than in group A.
Administration of VEGF injections at the distal part of a long random skin flap (length to width ratio 5:1) has been shown to improve the survival rate of the flap and thus contributing to the salvage of greater peripheral segment of the flap. Neovascularization induced by exogenous VEGF seems to be the biological mechanism, which leads to the improvement of flap survival.
血管生成的诱导已被证明是由多种称为生长因子的糖蛋白介导的。生长因子控制细胞的生长、分化和代谢。血管内皮生长因子（VEGF）被认为是这一过程中最有效的调节因子。研究了其外源性给药对长随机皮瓣远端三分之一的影响。
18只Wistar大鼠分为两组，每组9只。大鼠麻醉后，在其背部掀起一个1.5×7.5厘米的皮瓣。通过将蒂置于肩胛骨下角之间的中心位置并使用具有上述尺寸的框架来使皮瓣标准化。皮瓣的长度是其宽度的五倍。A组（n = 9）掀起皮瓣，在远端三分之一处皮下注射1毫升生理盐水，然后将其缝合回原位。B组（n = 9）掀起皮瓣，在远端三分之一处皮下注射10μg VEGF，然后再次缝合回原位。一周后对大鼠实施安乐死并切除皮瓣。对所有标本进行测量、拍照，放入10%的福尔马林中，并送去进行图像和组织学分析。图像分析用于评估存活面积和计算每平方毫米的平均血管密度。
皮瓣的坏死区域在一周内清晰可辨。A组皮瓣平均存活百分比为38.9%。B组为80.4%。组织学分析显示B组有血管生成，B组每平方毫米的平均血管密度高于A组。
已表明在长随机皮瓣（长宽比为5:1）的远端注射VEGF可提高皮瓣的存活率，从而有助于挽救皮瓣更大的周边部分。外源性VEGF诱导的新生血管形成似乎是导致皮瓣存活改善的生物学机制。
