载瘤动脉狭窄对颈内-后交通动脉动脉瘤血流动力学影响的初步分析

A preliminary analysis of the hemodynamic effects of parent artery stenosis on posterior communicating artery aneurysms

目的 评价瘤颈近端载瘤动脉狭窄对颈内-后交通动脉动脉瘤血流动力学的影响.方法 回顾性连续纳入2018年1—6月海军军医大学附属第一医院神经外科收治的颅内动脉瘤患者438例,其中颈内-后交通动脉动脉瘤患者74例,排除了未合并载瘤动脉狭窄患者55例,发生载瘤动脉痉挛1例,三维影像资料不全8例,数据无法满足血流动力学分析要求2例,最终纳入合并瘤颈近端(狭窄距动脉瘤颈1 cm以内)载瘤动脉狭窄的颈内-后交通动脉动脉瘤住院患者8例,其中男3例,女5例;年龄49~77岁,平均(63±11)岁.根据患者DSA三维重组后载瘤动脉狭窄形态,将8例患者分为偏心性狭窄组和同心圆性狭窄组,每组4例.构建基于病例特异性的三维动脉瘤模型,采用计算机软件模拟载瘤动脉不同狭窄程度(近端载瘤动脉分别模拟30%、50%、70%、90%四种狭窄程度)和不同狭窄距离(在距离动脉瘤1 cm内的近端载瘤动脉上分别选取2.5、5.0、7.5、10.0 mm四个距离),计算动脉瘤壁面切应力(WSS)和血流速度.采用线性混合效应模型对多水平数据进行分析.结果 (1)对偏心性狭窄组进行分析显示,狭窄距离每增加2.5mm,估计动脉瘤WSS平均降低1.040 Pa,估计狭窄处血流速度平均降低33.333 m/s(均P=0.01);狭窄程度每增加20%,估计动脉瘤WSS平均增加23.988 Pa,估计狭窄处血流速度平均增加0.485 m/s,差异均有统计学意义(均P<0.01).(2)对同心圆性狭窄组进行分析显示,狭窄距离每增加2.5 mm,估计动脉瘤WSS平均降低1.109 Pa,估计狭窄处血流速度平均降低29.412 m/s,差异均有统计学意义(均P<0.01);狭窄程度每增加20%,估计动脉瘤WSS平均增加19.099 Pa,估计狭窄处血流速度平均增加0.524m/s,差异均有统计学意义(均P<0.01).结论 载瘤动脉狭窄程度的增加可导致动脉瘤WSS增大,可能与颈内-后交通动脉动脉瘤进展有关.改善狭窄程度可有效降低动脉瘤WSS,但能否延缓甚至逆转动脉瘤的进展过程尚需进一步随访、验证.

Objective To evaluate the hemodynamic effects of the proximal parent artery stenosis on posterior communicating artery aneurysms.Methods From January 2018 to June 2018,438 patients with intracranial aneurysms were admitted to the Neurosurgery Department of the First Affiliated Hospital of Naval Military Medical University retrospectively.Among 74 patients with posterior communicating artery aneurysms,66 cases were excluded due to the absence of parent artery stenosis(55 cases),parent artery spasm(1 case),incomplete three dimensional(3D)image data(8 cases),and the unqualified data of hemodynamics analysis(2 cases).Finally,8 patients with proximal parent artery stenosis(≤1 cm to aneurysm neck)were included.There were 3 males and 5 females,aging from 49 to 77 years,with an average age of(63±11)years.All 8 patients were categorized as eccentric stenosis group(n=4)and concentric stenosis group(n=4)according to the lesion characteristic of 3D reconstruction by digital subtraction angiography(DSA).Based on the case specific 3D aneurysm model,computer software was used to simulate the different stenosis degree of the parent artery(30%,50%,70%,90%respectively)and distance between aneurysm and stenosis(2.5 mm,5.0 mm,7.5 mm,10.0 mm were selected on the parent artery within 1 cm of the aneurysm).The wall shear stress(WSS)and blood flow velocity were calculated.The linear mixed effect model is used to analyze the multi level data.Results(1)The analysis of the eccentric stenosis group showed that when the distance between aneurysm and stenosis was increased by 2.5 mm,the mean decrease of WSS was 1.040 Pa and the mean decrease of flow velocity was 33.333 m/s.The difference was statistically significant(all P=0.01).When the degree of stenosis was increased by 20%,the WSS would increase 23.988 Pa averagely and the blood flow velocity will also increase 0.485 m/s averagely(all P<0.01).(2)The analysis of concentric stenosis group showed that when the distance was increased by 2.5 mm,the mean decrease of WSS was 1.109 Pa and the mean decrease of flow velocity was 29.412 m/s.The differences were statistically significant(all P<0.01).When the degree of stenosis was increased by 20%,the mean increase of WSS was 19.099 Pa and the mean increase of flow velocity was 0.524 m/s.The differences were statistically significant(all P<0.01).Conclusions The aggravation of the parent artery stenosis is positively relative to the WSS of aneurysm,which may lead to the development of posterior communicating artery aneurysms.Stenosis recovery can effectively reduce WSS,but whether it can delay or even reverse the development of aneurysm needing more follow up research for the patients and further verification.