天然水蛭素水凝胶可改善随意皮瓣的存活

背景：随意皮瓣移植后易发生瘀血，甚至缺血坏死，临床与动物实验已经证明水蛭素能够提高皮瓣的存活率。 目的：探讨天然水蛭素凝胶对大鼠随意皮瓣存活的影响。方法：制备天然水蛭素凝胶，用改良的Franz扩散池进行经皮渗透实验，使用Markwardt法进行水蛭素活性的检测。选用Wistar大鼠，在其背部设计随意皮瓣，面积为9 cm×3 cm；皮瓣随机分3组，分别涂抹生理盐水、天然水蛭素凝胶、空白凝胶基质。术后进行大体、组织病理学形态观察，第7天计算皮瓣存活率。结果与结论：体外实验：Markwardt法检测到天然水蛭素凝胶组的活性成分能透过皮肤，而空白凝胶组未检测到任何活性成分。体内实验：术后7 d，天然水蛭素凝胶组皮瓣坏死长度明显长于生理盐水组、空白凝胶基质组，差异有显著性意义（P 〈 0.05）。术后 3 d，天然水蛭素凝胶组真皮内毛细血管及微静脉红细胞瘀滞现象较生理盐水组、空白凝胶基质组明显减轻；术后7 d，天然水蛭素凝胶组皮下胶原及肉芽组织增生明显优于生理盐水组、空白凝胶基质组；术后7 d，天然水蛭素凝胶组皮瓣存活率高于生理盐水组、空白凝胶基质组，差异有显著性意义（P 〈 0.05）。结果表明天然水蛭素可渗透进入完整皮肤组织，局部应用天然水蛭素水凝胶同样对皮瓣移植后瘀血有改善作用，有利于新生血管的生成。

Natural hirudin hydrogel improves the survival rate of random pattern flaps

BACKGROUND： A random pattern flap is prone to resulting in blood stasis and even ischemic necrosis. Clinical and animal experiments have proved that hirudin can improve the survival rate of the pattern flap.OBJECTIVE： To discuss the effects of natural hirudin hydrogel on the survival of rat random pattern flaps.METHODS： Natural hirudin hydrogel was prepared for percutaneous permeation experiment using modified Franz diffusion cell. Markwardt method was used to detect hirudin activity. Random pattern flaps from the back of Wistar rats, 9 cm × 3 cm, were used for flap preparation. The flaps were randomized into three groups, normal saline group, hirudin group and blank gel matrix group. Postoperative gross, histopathological, and morphological observations were conducted, and the survival rate of the flaps was calculated at day 7.RESULTS AND CONCLUSION： In vitro experiments： The active ingredient of the natural hirudin hydrogel passed through the skin, but there was no active ingredient in the blank gel group. In vivo experiments： After 7 days, the length of necrotic flaps in the hirudin group was significantly longer than that in the normal saline and blank gel matrix groups （P 〈 0.05）. After 3 days, the phenomenon of red blood cell stasis in dermal capillaries and venules was significantly reduced in the hirudin group as compared with the normal saline and blank gel matrix groups; after 7 days, subcutaneous collagen and granulation tissue hyperplasia was more obvious in the hirudin group than in the normal saline and blank gel groups; after 7 days, the survival rate of flaps in the hirudin group was significantly higher than that in the normal saline and blank gel matrix groups （P 〈 0.05）. Natural hirudin permeate the intact skin tissue, and local application of natural hirudin hydrogel can improve blood stasis after flap transplantation and be conducive to the formation of new blood vessels.