外科延迟术对跨区皮瓣多血管体间微循环重构的影响

目的建立小鼠背部单穿支和多穿支跨区皮瓣模型,探讨3种延迟术对皮瓣微循环重构的影响,术后中央choke区内皮型一氧化氮合酶(e-NOS)、基质金属蛋白酶-2(MMP-2)的变化以及该区域血流对其形态学的影响。方法 Balb/c小鼠100只,随机分为对照组(10只)及实验A、B、C组(每组30只)。A组结扎右胸背穿支;B组结扎2条右侧穿支;C组仅保留左胸背穿支。各实验组分别于术前、术后6h、1d、3d、5d、7d用激光多普勒血流仪连续监测choke区,观察血管形态学变化,并取材进行HE染色,对目的蛋白的表达进行检测(Western blotting)及定位(免疫组织化学染色)。结果与术前相比,术后各组choke区血流增加明显,差异且有统计学意义(P0.01);此区血管曲度也明显增加,管径增粗,管壁增厚,蛋白含量增加,目的蛋白主要定位于血管内及其外周。结论术后各组choke区呈现不同的血流动力学与血管形态学变化特点,即微循环重构;以保留单穿支的延迟方式对跨区皮瓣choke区微循环重构影响最大;e-NOS、MMP-2参与了血管新生过程。

Effect of delayed surgery on microcirculation remodeling among multi-vessels of the crossed-flap

Objective To investigate the effect of different delayed surgeries on microcirculation remodeling of the crossed-flap after modeling single-and multiperforator-based flaps on the back of the mouse, and examine the changes of endothelial nitric oxide synthase (e-NOS) and matrix metalloproteinase-2(MMP-2) of the choke area. How blood flowing through the choke area affects the morphology of choke vessels was also studied. Methods A total of 100 healthy Balb/c mice were randomly divided into a control group(n=10),and three experimental groups (n=30,each).Group A, which the right thoracodorsal perforator was ligated;group B in which both the right thorac odorsal and iliac lumbar perforators were ligated, and group C in which the left thoracodorsal perforator was intact but the rest of other three perforators were ligated.Laser Doppler measureme nts were made preoperatively and postoperatively at the 6th hour, day 1, day 3, day 5 and day 7 in zone C of each group. Morphology changes of the vessels within the flap was observed. HE staining was used to observe changes of choke vessels. Western blotting was performed for protein detection. The proteins were localized by immunohistochemistry. Results Compared with control group, blood flow in the experimental groups had an obvious increase postoperatively,and the difference was statistical significance(P<0.01). The increasing vascular curvature in the choke area of experimental groups was seen.HE staining showed the dilated diameter and the thicken wall. The protein levels of e-NOS and MMP-2 were increased and mainly located in and around the walls of vessels. Conclusion The characteristics of morphology and hemodynamic (microcirculation remodeling) of choke area in experimental groups are different. The delayed surgery that keeps single-perforator intact has the greatest impact on microcirculation remodeling. e-NOS and MMP-2 have an effect on angiogenesis.