PURPOSE To preliminarily establish a hemodynamic 3D numeric model of radial forearm free flap with vascular pedicle of radial artery and vein, and discuss its scientific workability. METHODS The 3D geometric model of 50mm×80mm×10mm radial forearm flap was established by Pro/E(Wildfire 4.0). The vascular pedicle was 50mm in length including radial artery (inside diameter was 1.9mm) and concomitant radial vein (inside diameter was 0.84mm). The half-embedded vessels went hrough the flap paralleling the long axis. Then the established geometric model was transferred to the SC/Tetra 8.0 software for mesh generation and calculation. According to the virtual flow volume of the radial artery, the inlet velocity was set as 20mm/s. With the different blood pressure of 53mmHg between the feeding artery and draining vein, the tentative porous values were achieved. Then porous model was applied to the flap to simulate the capillary structure. The pressure distribution on the central axis of radial artery and vein and the radial velocity distribution in three different cross sections of vessels were figured out. RESULTS A model with 10355473 meshes and 2104014 nodes was built. When porous model was applied, the pressure difference between radial artery and vein was calculated to 7050 Pa (52.8mmHg), which was close to clinical value. The computational fluid dynamic analysis results showed that with porous model, the central pressure of radial artery was continuously kept to a higher level. When blood flowed in and flows out of the flap, the blood velocity decreased and increased greatly. While the central pressure of radial vein significantly decreased at the moment of blood flowing out of the flap. These results basically agreed with the features of normal blood circulation of the forearm flap. CONCLUSIONS Porous model effectively simulates hemodynamic status of forearm flap, which provides a new method for the study of mechanism of blood circulation in radial forearm flap and also lays a foundation for the following hemodynamic study of vascular anastomosis.

中文翻译：

---

radial骨前臂游离皮瓣血流动力学模型的建立

目的初步建立with动脉和静脉血管蒂的ped前臂游离皮瓣血流动力学3D数值模型，并探讨其科学实用性。方法采用Pro / E（Wildfire 4.0）建立50mm×80mm×10mm radial骨前臂皮瓣的3D几何模型。血管蒂的长度为50mm，包括radial动脉（内径为1.9mm）和radial骨静脉（内径为0.84mm）。半嵌入式血管通过皮瓣平行于长轴。然后将建立的几何模型转移到SC / Tetra 8.0软件中，以进行网格生成和计算。根据the动脉的虚拟流量，将入口速度设置为20mm / s。由于进食动脉和引流静脉之间的血压不同，为53mmHg，获得了初步的多孔值。然后将多孔模型应用于襟翼以模拟毛细管结构。得出radial动脉和静脉中心轴上的压力分布以及三个不同血管截面中的径向速度分布。结果建立了一个具有10355473网格和2104014节点的模型。应用多孔模型时，radial动脉和静脉之间的压差计算为7050 Pa（52.8mmHg），接近临床值。计算流体动力学分析结果表明，采用多孔模型，radial动脉的中心压力连续保持在较高水平。当血液流入皮瓣并从皮瓣流出时，血流速度下降并大大增加。而当血液从皮瓣流出时，radial静脉的中心压力显着降低。这些结果基本符合前臂皮瓣正常血液循环的特征。结论多孔模型可有效模拟前臂皮瓣的血流动力学状态，为研究radial骨前臂皮瓣的血液循环机理提供了新的方法，也为后续血管吻合术的血流动力学研究奠定了基础。