肛瘘封堵器的材料设计与生物力学研究

针对肛瘘的手术治疗，设计一款可降解的肛瘘封堵器，主要利用高温熔融法制备不同分子量、不同基团的左旋聚乳酸试件，通过拉伸试验获得材料的应力–应变曲线，确定了封堵器的最佳制作材料。利用有限元仿真分析软件ABAQUS，系统地研究了封堵器在植入过程中的应力–应变分布以及径向支撑力等参数的变化。结果表明：分子量为110万、基团为酯封端的左旋聚乳酸弹性模量值最高；封堵器在封堵过程中受到的最大应力没有超过其许用应力（4.55 kPa），初始接触阶段应力仅集中在封堵器周围区域，并且距离接触中心越远，应力值越大；随着封堵器的不断侵入，接触应力以环形波的方式从接触中心向四周扩散；封堵器基本保持了初始形状，没有发生明显的挤压变形，在封堵过程中具有良好的封堵效果且不易被破坏。

Material design and biomechanical study on sealing device for anal fistula

Aiming at the surgical treatment of anal fistula, a degradable anal fistula sealing device was designed. L-polylactic acid specimens with different molecular weights and different groups were prepared by high-temperature melting method. The stress-strain curve of the material was obtained by tensile test, and the best material for the sealing device was determined. Finite element simulation analysis software ABAQUS was used to systematically study the stress-strain distribution and radial support force during the sealing process. The results showed that the elastic modulus of L-polylactic acid is the highest with the molecular weight of 1.1 million and the group is ester-sealed. The maximum stress of the sealing device in the process of sealing did not exceed its allowable stress 4.55 kPa. In the initial contact stage, the stress was only concentrated in the area around the sealing device, and the further away from the contact center, the greater the stress value was. The contact stress diffused from the contact center to all sides in the form of ring wave with the continuous intrusion of the sealing device. The sealing device basically maintained the initial shape and did not have obvious extrusion deformation.It would not be crushed in the sealing process and had a good sealing effect.