颅内动脉瘤介入治疗效果评价的体外模拟实验研究

Intracranial aneurysm is one of the most common diseases that cause serious damage to human health. Endovascular embolization has been widely used as a safe and effective treatment method. The changes about the aspect ratio of aneurysm, flow in the aneurysm and the movement of the coil will have a deep relationship with the recurrence of the aneurysms after coil embolization. If the effectiveness of surgical treatment can be quantitatively evaluated, it will have a guiding significance on postoperative nursing and prevention of recurrence. Hemodynamics, as the main factor influencing the aneurysm rupture and postoperative recurrence, has been paid wide attention throughout the word. Interventional embolization treatment involved the interactions among the vascular elasticity, embolization coils, and pulsatile blood flow. The changes of local hemodynamic characteristics in the aneurysm before/after operation have a certain relationship with the recurrence of the aneurysm. Therefore, this work, based on the coil embolization treatment of intracranial aneurysm, will try to obtain the displacement response of aneurysmal wall and embolization coil, and the flow characteristics in the aneurysm at the same time by using the method of in vitro experiment under the situation between the action of pulsating blood flow and the existence of coil. The objective of this project is to investigate the mechanism of fluid-structure interaction of among the elasticity of blood vessels, pulsating blood flow, and embolization coil, and the effect of interventional embolization on the local hemodynamic characteristics in the aneurysm. It will be very important in quantitative evaluation, postoperative nursing and prevention of recurrence after coil embolization treatment.

颅内动脉瘤是威胁人类健康的常见疾病之一。介入栓塞手术是一种安全有效的治疗手段，但术后瘤颈比的改变、载瘤母血管内流动状态的变化，植入线圈松动或脱落都关系着动脉瘤二次复发。如能定量评价手术的治疗效果，对术后护理和预防复发有着指导意义。血流动力学作为影响动脉瘤破裂及术后复发的主要因素，被国内外学者广泛重视。介入栓塞手术是血管弹性、栓塞线圈，以及血液流动之间相互耦合的过程，手术前后动脉瘤血流流动特性的改变程度将直接影响介入手术的治疗效果以及术后的复发风险。因此，本项目主要基于颅内动脉瘤介入栓塞手术，通过体外实验的方法，针对在脉动血流作用下，以及栓塞介质参与的同时，进行瘤体位移响应、栓塞线圈位移响应以及瘤内流场的同步观测，考察血管弹性、植入介质和脉动血流间流固耦合的作用机制，以及对动脉瘤血流动力学特性的影响，这一研究将对动脉瘤介入手术疗效的定量评价以及术后复发的预防有着重要意义。

颅内动脉瘤是威胁人类健康的常见疾病之一。血流动力学作为影响动脉瘤破裂及术后复发的主要因素，被国内外学者广泛重视。动脉瘤手术过程涉及血管弹性、血液流动之间相互耦合，手术前后动脉瘤血流流动特性的改变程度将直接影响手术的治疗效果以及术后的复发风险。在本项目中，研发了载瘤弹性血管物理模型制作方法，搭建了具有脉动流动特性的体外模拟系统。通过体外实验的方法实现了囊形血管壁面位移响应及其瘤颈局部流动特性的同步追踪，探究了个性化动脉瘤瘤体变形、脉动血流、末端阻抗以及动脉瘤瘤颈比之间的相互影响。主要的研究结果表明：动脉瘤的空间结构和夹闭手术策略对动脉瘤手术后的血流动力学特性影响较大。模拟手术前，动脉瘤瘤囊内存在明显的涡流，涡流随着动脉瘤的夹闭而消失。并且动脉瘤瘤颈位置处存在明显的流动冲击区，在该冲击区的压力较高。当冲击区靠近壁面时，其壁面剪应力较高。当夹闭手术平面垂直于血流占优侧前脑动脉A1段的流动方向时，来流冲击区域与夹闭位置较为接近，该处的压力较高。在理想以及个性化动脉瘤的流固耦合实验研究中发现，脉动流动和末端阻抗对动脉瘤内流动特性和变形特性影响较大。在脉动流动下，瘤囊内部的涡呈现周期性循环运动。但随着脉动频率的增加，涡心运动的无序性也随之增大，动脉瘤瘤顶的变形逐渐增大。当动脉瘤出流处末端阻力的增加时，涡心运动逐渐整体向瘤顶方向靠近，动脉瘤瘤顶的变形也随着增大。此外，当AR<1.0时，随着瘤颈比的增加，个性化动脉瘤模型瘤顶的形变均逐渐减小。当AR>1.0，瘤顶形变随瘤颈比的增加逐渐增大,特别地，当AR>1.5时，瘤顶形变的升高趋势较1.0<AR<1.5时更为明显。这一研究对认识动脉瘤破裂机制提供帮助。