Choke vessels 血流动力学可视化定量回归分析

Coverage of large, complex wounds remains a great challenge for plastic surgeons. A large soft-tissue defect caused by such things as trauma, tumor and burn is impossible to cover by one axial local flap. Up to now, the flap vascular structure and function of the junction is not clear, so the confusion has often been encountered by plastic surgeons who want to harvest a cross-boundary flap. McGregor and Taylor believed that anastomosis between adjacent arteries normally has little or no blood flow. The resistance vascular constitutes a linear "closed" border, a special term, choke vessel was named. However, our latest information indicates that anastomotic zone has blood flow, does not support the "closed" and "resistance" doctrine. We hypothesis that every choke blood vessels has dilated trend and controllable, and a cross-boundary flap can be created by the choke vessel artificially altered. In order to verify hypotheses, we plan to observe in vivo the vascular density, diameter, normal and potentially opening up blood vessels of the ratio in choke vessel zone. We will also investigate the range of arterial and venous flow speed, and stress changes in the choke area. Two different animal modes will be use to test the hypotheses,"intravital fluorescent staining with tissue clearing in displaying microvascular architecture"and"The observation chamber technique for in vivo study of the choke anastomotic region". Purposes of this study are to rreveal the vascular morphology and hemodynamic characteristics, and provide a theoretical foundation for designning a large flap in clinical by explore how to dilate choke vascular and establish the blood supply channels to cross-boundary flap.

创伤或肿瘤切除等可导致大范围的缺损，其损伤面常超过轴型皮瓣所能覆盖的范围。然而，皮瓣血管结合部的结构与功能尚不明了，临床上跨区切取大皮瓣时常遇到种种困惑。McGrego及Taylor等认为：相邻动脉间的吻合支逐渐变细,构成一条线状的"封闭"边界，吻合处无血液流动，特称之为阻力性血管(choke vessels)。最新资料显示吻合处有血液流动，不支持"封闭"、"阻力"学说。据此认为：1 任一choke血管都有可扩张趋势，且可控；2 可人为地改建choke血管，定向设计跨区大皮瓣。我们拟应用"原位整体标记共聚焦免疫荧光术"及"微血管直视模型"等，观测活体choke血管区域的血管密度、管径，正常与潜在开放血管之比率，以及区间动、静脉血流速度、流量及应力变化等验证以上两点假说。揭示区间的血管形态学及血流动力学之特征；探讨如何通过choke血管建立起跨区供血渠道，为临床设计跨区大皮瓣提供理论支撑。

创伤或肿瘤切除等可导致大范围的缺损，其损伤面常超过轴型皮瓣所能覆盖的范围。已知相邻皮动脉间有广泛的吻合（choke血管），具备将皮瓣扩大切取之形态学基础。然而，choke血管在吻合处是逐渐变细的，若能采取措施将其扩张为真性连接，那么任一动脉都能通过choke血管跨区营养更大的范围。.本实验室应用“放射造影剂标识血管及其3D可视化技术”，成功地完成了皮动脉及其之间的choke血管的3D可视化建模。同时通过3个大鼠背部“跨区皮瓣模型”，对术后各个时间点的经皮灌注量和氧分压的监测，以及应用Western blotting，ELISA法检测皮肤PCNA、HIF-1、SDF-1、VEGF等蛋白水平证实：①从术后6h到7d，静脉超引流的氧分压和血流量最高，能更好地改善微循环的血流动力学。②尾静脉注射二甲氧乙二酰甘氨酸（dimethyloxalylglycine，DMOG）可稳定HIF-1活性。促进局部微血管新生，改善微循环。③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。.实验成功地验证了我们提出的两点假说：①任一choke血管都有可扩张趋势，且可控；②可人为地改建choke血管，定向设计跨区大皮瓣。也证实了本项目组提出的数字模型是科学而实用的。据此可计算出多穿支皮瓣内的各部分及总的阻力为 (注: 数学公式显示不出来,详见正文)，可辅助判断和评估各部分及整个皮瓣成活的难易程度。.本项目发表论著11篇(SCI收录4篇)，学生第一作者论著7篇，中青年医生第一作者论著4篇，并助力团队荣获2016年浙江省科技进步二等奖1项。项目负责人主持“中国显微外科穿支皮瓣高峰论坛4届(每年1次)”，主持国际学术会议1次(16th Annual International Course on Perforator Flap)。还成功地为下一步研究进行了2项实验预试。