动脉生成在跨区穿支皮瓣choke血管重塑中的作用及其分子机制

After a cutaneous flap is raised or delayed, the choke vessels within the flap undergo the remodelling with increased caliber and wall thickness and tortuose course. However, the revascularization mode and molecular mechanism of the remodelling is unclear. Most researchers believe that the remodelling proceeds via angiogenesis or vasculogenesis manner. Little information is available concerning role of arteriogenesis in remodelling of choke vessels within a flap (particularly multi-angiosomes perforator flap) and its molecular mechanism. Perforator flaps have been widely used in clinical practice. We hypothesize, according to the published literatures and our previous experiments, that the molecular mechanism of the remodelling of the choke vessels within a multi-angiosomes perforator flap is closely associated with temporal and spacial changes of the protein molecules which are involved in arteriogenesis (i.e. collateral artery growth). Using the model of the perforator flap on the back of rat, we will observe the dynamic changes occurring in the choke vessels of the flap in morphology (including radiograph, microstructure and ultrastructure), fluid shear stress reflected by blood flow velocity and perfusion volume, and expression of the proteins involved in arteriogenesis, which is examined by immunofluorescence histochemistry under a laser scanning confocal microscope. We will also observe the influence of both the intervention chemicals (including donor of NO, IL10, CXCL1 and MAb) and altered fluid shear stress on the remodelling of the choke vessels. We attempt to elucidate protein-molecular mechanism in the remodelling of the choke vessels within a multi-angiosomes perforator flap, and verify the crucial role of arteriogenesis in the remodelling. Our findings will provide experimental evidences, efficient trearment strategies and new clues for optimal application of perforator flaps.

皮瓣掀起或延迟后，皮瓣内choke血管经历管径增大、管壁增厚等重塑过程，其血管再生方式及分子机制尚不清楚，多数学者认为是通过血管生成（angiogenesis）或血管发生（vasculogenesis）方式进行。动脉生成（arteriogenesis）方式在皮瓣（尤其是跨区穿支皮瓣）血管重塑中的作用及其分子机制的研究罕见文献报道。结合文献和我们的前期观察，我们推测跨区穿支皮瓣内choke血管重塑的分子机制与动脉生成相关蛋白分子的时空动态变化密切相关。本课题拟采用大鼠背部跨区穿支皮瓣模型，观察choke血管的形态学、血流切应力及动脉生成相关蛋白分子表达的动态变化；观察药物干预和改变血流切应力对choke血管重塑的影响。本研究旨在阐明跨区穿支皮瓣choke血管重塑的蛋白分子机制，证实动脉生成方式在choke血管重塑中起关键作用，为临床最佳化应用跨区穿支皮瓣提供实验依据、有效途径和新思路。

研究背景：.皮瓣掀起或延迟后，皮瓣内choke血管经历管径增大、管壁增厚等重塑过程，其血管再生方式及分子机制尚不清楚。多数学者认为皮瓣内血管重塑是通过血管生成（angiogenesis）方式进行的,少数学者认为重塑是通过血管新生（vasculogenesis）方式进行的。我们推测动脉生成方式在跨区穿支皮瓣choke血管重塑中起关键作用。choke血管重塑的分子机制与动脉生成相关蛋白分子的时空动态变化密切相关。.主要研究内容： .1.跨区穿支皮瓣内 choke 血管重塑过程中血管形态的动态变化：①氧化铅-明胶灌注 ②HE染色。2.choke 血管内血流切应力的动态变化：①注射伊文思蓝，测量choke血管区的血流速度 ②激光多普勒血流仪测量choke血管区的血流灌注量。3.choke血管重塑过程中动脉生成相关蛋白分子表达的免疫荧光组化研究。4.改变血流切应力对跨区穿支皮瓣 choke 血管重塑的影响及其机制。.重要数据和结果： .血管形态观察：choke动脉在术后1h、4h及6h密度稀疏、管径细小；术后1d密度增加、管径增粗；术后3-7d，choke区出现数条管径粗大，行程迂曲的真性吻合动脉；术后14d，choke动脉密度、管径较前回落。血流速度测量：choke动脉在术后即刻就有血流通过，术后6h血流速度开始明显增快，术后18h-24h达到高峰，术后3d血流速度较前减慢，随后趋于平稳。血流灌注量：choke区血流灌注量在术后1h、4h、6h均低于术前，术后1d高于术后6h，术后5d高于术后3d，术后7d低于术后5d，差异有统计学意义（P<0.05）；在术后1d、3d、5d、7d及14d与术前差异无统计学意义（P>0.05）。免疫荧光：CD31、Cx37和CD68与choke血管的重塑密切相关。采用多种的手术干预改变choke区血流切应力可提高choke血管的重塑效率和程度。.科学意义：.本研究阐明了动脉生成方式在跨区穿支皮瓣choke血管重塑中具有重要作用，并初步阐明了其分子机制。研究结果可以为临床上设计切取跨区穿支皮瓣提供指导；也可为临床上采用影响动脉生成过程的干预措施来改善皮瓣血供、提高成功率提供实验依据。