犬实验性动脉瘤血管内支架置入前后对照研究

目的探讨囊状动脉瘤行血管内支架治疗前后血流动力学、病理学变化与动脉瘤生长、血栓形成或破裂之间的相互关系.方法采用静脉移植法建立9只犬颈总动脉动脉瘤模型,1周后行彩色多普勒超声及DSA检查.5只犬于动脉瘤口成功置入支架,1个月后再行彩色多普勒超声、DSA及组织病理学检查.结果 DSA、彩色多普勒超声检测能显示动脉瘤位置、形态,并能检阅支架置入前后瘤体内及载瘤动脉内血液循环状态.置入支架组1个月后瘤腔完全闭塞,新生纤维样组织环绕支架金属丝表面.结论支架置入后改变了动脉瘤附近血流动力学,可促进瘤腔内血栓形成.     

犬囊状动脉瘤微弹簧圈栓塞治疗前后的超声研究

目的探讨囊状动脉瘤模型的声像图和血流动力学特征以及超声对其血管内栓塞效果的评价。方法利用用显微外科技术于犬颈总动脉制成三种类似于人类的囊状动脉瘤模型，其中侧壁型12例、分叉型4例、末端型6例。术后7～14d彩超观察瘤腔、载瘤动脉及瘤体内血流动力学改变。栓塞后再行彩超检查观察其疗效，并与MRA、DSA及病理检查结果对比。结果三种类型动脉瘤均有相似的血流模式，瘤腔内血流分为三个血流区：1)沿远侧瘤壁进入的流人区；2)沿近侧瘤壁出去的流出区和3)中心缓慢涡流区。流人区峰速高于流出区。②侧壁型动脉瘤内血流速较慢，易形成部分性血栓，而分叉型和末端型动脉瘤内血流速高。③血管内治疗后，血流显示19例动脉瘤腔闭塞，2例瘤颈部有残腔，1例弹簧圈略脱出瘤颈导致载瘤动脉狭窄。④超声结果与MRA、DSA及病理结果完全一致。结论①各型动脉瘤模型有相似的血流模式。②侧壁型动脉瘤顶部易形成部分血栓。③双功超声能观察载瘤动脉及瘤体内血流动力学改变，可作为动脉瘤及栓塞治疗效果无创评价的方法之一。     

微血管多普勒在脑动脉瘤夹闭术中的应用

目的探讨微血管多普勒（MVD）在脑动脉瘤夹闭术中的应用价值。方法在23例26个脑动脉瘤夹闭前、后，使用MVD对动脉瘤、载瘤动脉和相关穿支动脉检测血流动力学的改变。动脉瘤夹闭后，瘤体内涡流存在时，加强瘤颈的夹闭力，载瘤动脉或穿支动脉血流降低或消失时，改变动脉瘤夹夹闭位置，使载瘤动脉和或穿支动脉的血流恢复至正常。结果所有动脉瘤均检测到涡流或毛刺样血流信号。21个动脉瘤夹闭术后，瘤体内涡流消失，载瘤动脉及其分支血流频谱良好；3个动脉瘤行孤立术后，瘤体内频谱消失，2个巨大动脉瘤行动脉瘤夹闭加清除术。动脉瘤夹闭术中，不完全夹闭2个动脉瘤，4个动脉瘤载瘤动脉血流速度增快，调整动脉瘤夹夹闭位置后，血流速度恢复正常。术后头颅CT示，所有病例无脑梗死。3例眼动脉瘤、2例小脑后下动脉瘤和1例小脑上动脉瘤出院前作DSA检查，动脉瘤消失，载瘤动脉和相关血管无闭塞或狭窄现象。其他病例均作CTA复查，载瘤动脉及周围血管保留良好，动脉瘤消失。结论MVD在动脉瘤夹闭术中是一种安全直接，快速简便和经济有效的监测方法。     

微血管多普勒超声在颈内动脉瘤手术中的应用

目的 探讨微血管多普勒超声(MVD)在颈内动脉瘤手术中的应用.方法 采用探头频率20MHz、直径1.5 mm,对32例颈内动脉瘤患者(共计36个动脉瘤)进行动脉瘤夹闭前后血流动力学监测.术后血管造影进行评估.结果 所有患者均能在动脉瘤顶或瘤体部监测到涡流样或毛刺样血流信号、闻及杂音.动脉瘤夹闭术后即刻监测,发现载瘤动脉狭窄8例,闭塞1例;动脉瘤夹闭不全2例,均经调整瘤夹位置,显示载瘤动脉远段的血流频谱形态和音频信号正常,术后经DSA/CTA证实.以上情况的发生与动脉瘤大小及载瘤动脉有粥样硬化斑块有关.结论 MVD可作为颅内动脉瘤手术的常规检测方法,尤其对瘤颈粗、甚至无明显瘤颈的巨大型动脉瘤手术具有指导意义.     

醋酸纤维素聚合物栓塞实验性宽颈动脉瘤的组织学研究

目的观察实验性宽颈动脉瘤被非黏附性液体栓塞剂醋酸纤维素聚合物(CAP)栓塞后的组织学变化。方法犬3只,将颈外动脉和股深动脉结扎建立动脉残端性宽颈动脉瘤模型,随即向动脉瘤腔内注射CAP(注射时用血管夹夹闭动脉瘤颈)。3周后取动脉瘤标本做电镜检查。结果3只动物共制作12个动脉瘤,7个用CAP栓塞。扫描电镜显示瘤体内的CAP团块与动脉瘤内膜紧密贴合,有4个动脉瘤的瘤颈被较完整的新生内皮细胞覆盖。透射电镜显示瘤壁存在轻度炎症,瘤腔被CAP及纤维组织充填。结论宽颈动脉瘤被CAP栓塞后能够达到组织学上表现为瘤颈内皮化和瘤腔纤维化的解剖愈合。     

实验性兔侧壁动脉瘤模型建立及彩色多普勒研究

目的:仿造浆果样动脉瘤形态建立兔侧方动脉瘤模型,并行彩色多普勒超声检测评估。方法:20只兔采用全麻和显微外科的方法,将颈外静脉段与颈总动脉行端侧吻合,术后及1个月后分别行彩色多普勒超声检测。结果:20只兔制成17个大小相似的侧壁型动脉瘤并行超声检测。1个月后,11只兔完成第二次多普勒检查。彩色多普勒可鲜明地显示动脉瘤内的血流方向和状态。结论:应用颈外静脉段与颈总动脉行端侧吻合建立兔动脉瘤模型切实可行,但成功率较大动物低。超声检测可反映出瘤内的血流状态。     

彩色多普勒超声对椎基底动脉供血不足的临床诊断

目的探讨彩色多普勒超声血流显像及参数对椎基底动脉供血不足的诊断。方法用10Hz探头探查颅外段椎基底动脉血管形态、内径、血流频谱及血流动力学变化。结果156例患者有124例异常,表现为频谱形态的改变及血流速度的异常。结论彩色多普勒超声能准确判断椎动脉的血管结构,定量血流动力学变化。     

兔颈总动脉侧壁型动脉瘤模型的建立

目的 建立类似人颅内动脉瘤特点的兔颈总动脉侧壁型动脉瘤模型.方法 切取兔左颈总动脉约8mm,经弹性蛋白酶和胶原酶处理后,采用端侧吻合法将其吻合到右颈总动脉,建立侧壁型动脉瘤20只.术后分别行彩色多普勒检查、DSA和动脉瘤壁病理检查.结果 本组建立兔颈部囊状动脉瘤模型20只,术后健康成活18只,动脉瘤自发破裂导致死亡2只.DSA显示:动脉瘤与载瘤动脉通畅16只,动脉瘤腔自发性完全闭塞2只;造模成功率为80％.彩色多普勒发现:动脉瘤模型建立后即刻平均直径为(2.57±0.20) mm,2周后平均直径为(3.14±0.20) mm,两者差异有统计学意义(P＜0.05);且载瘤动脉血流速度较动脉瘤内血流速度快.病理检查显示:动脉瘤模型的动脉壁内弹力层和中弹力层基本消失.结论 经弹性蛋白酶和胶原酶处理的兔颈总动脉侧壁型动脉瘤模型,在形态结构、组织结构、自然发展史及血流动力学特点上与人颅内动脉瘤相似,是模拟人颅内动脉瘤的最佳模型之一.     

颈动脉狭窄动物模型及经皮血管成开采主后的二维和彩色多普勒实验研究

目的： 评价二维和彩色多普勒对颈动脉狭窄及疗效判断的价值。方法：用球囊加血管环扎法建立犬颅外段颈动脉狭窄模型，对其在经皮血管成形术（PTAS）治疗前及治疗后即刻、1月、2月、3月行高频超声动态观察，并与同期DSA检查及病理检查结果比较，结果：（1）超声能准确确定动脉狭窄部位，范围，程度以及血流动力学改变。（2）PTAS治疗后，超声能观察支架位置形态，支架处管腔内径，彩色及频谱多普勒能观察支架内部及近远段血管内血流动力学改变，并根据血流动力学改变判断再狭窄的发生和狭窄程度。（3）PTAS术后，超声不清楚显支架内壁及腔内结构，支架内血流信号显示不丰满，结论：超声对颈动脉狭窄诊断及疗效判断有重要价值，是临床首选的无创检查方法。     

微血管多普勒超声在颅内动脉瘤手术中的应用

目的探讨微血管多普勒(microvascular Doppler,MVD)在颅内动脉瘤手术中的作用。方法应用MVD对20例颅内动脉瘤患者(共计21个动脉瘤)进行动脉瘤夹闭前后监测,记录动脉瘤、载瘤动脉及分支的血流速度和频谱,根据MVD检查结果重新调整瘤夹。结果所有动脉瘤患者均探及瘤体内呈毛刺样、涡流样杂音频谱。15例动脉瘤夹闭的患者中,3例因载瘤动脉或分支血管狭窄而调整动脉瘤夹位置;动脉瘤夹闭术后,瘤体内均未探及血流信号,无音频和频谱显示,证实已被完全夹闭,而载瘤动脉及分支血流频谱波动性良好;8例动脉瘤患者术中运用MVD协助区分巨大动脉瘤和载瘤动脉走行。结论动脉瘤夹闭术中运用MVD同步进行动脉瘤及载瘤动脉血流动力学监测,可根据检查结果调整动脉瘤夹位置,具有无创、简单易行,安全的特点。建议MVD作为颅内动脉瘤手术的常规监测方法,尤其对瘤颈粗、甚至无明显瘤颈的巨大动脉瘤手术具有指导意义。     

Wall shear stress in intracranial aneurysms and adjacent arteries

Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.     

Saphenous vein graft bypass in the treatment of giant cavernous sinus aneurysms: report of two cases

Two cases of giant intracavernous aneurysms treated by high flow bypass with saphenous vein graft between the external carotid artery (ECA) and branches of the middle cerebral artery (MCA) are presented. Very often these aneurysms are unclippable because they are fusiform or have a large neck. Occlusion of the internal carotid artery (ICA) is the treatment of choice in many cases. This procedure has however a high risk of brain infarction. Revascularization of the brain by extra-intracranial anastomosis between the superficial temporal artery (STA) and branches of the MCA is frequently performed. This procedure provides however a low flow bypass and brain infarction may occur. We report two cases of giant cavernous sinus aneurysms treated by high flow bypass and endovascular balloon occlusion of the ICA. Immediate high flow revascularization of MCA branches was achieved and the patients showed no ischemic events. Follow-up of 8 and 14 months after operation shows patency of the venous graft and no neurological deficits. Angiographic control examination showed complete aneurysm occlusion in both cases.     

Xenon/CT CBF measurements as valuable diagnostic tool in a case of bilateral occlusive cerebrovascular disease associated with intracranial aneurysm

A patient with the coincidental occurrence of a right internal carotid artery (ICA) stenosis and asymptomatic ipsilateral infraclinoidal ICA aneurysm is presented. CBF measurements including testing of the cerebrovascular reserve capacity (CRC) demonstrated a compromise of cerebral blood flow (CBF) within the anterior circulation of the affected side. We treated the patient in one operation by aneurysm clipping and subsequent carotid endarterectomy (CEA). 10 months later she presented with an occlusion of the contralateral ICA. CBF measurements showed sufficient resting flow and CRC on both sides. One year later repeat measurements disclosed a lowered resting CBF and diminished CRC on the affected side. Extracranial/Intracranial (EC/IC) artery bypass improved both symptoms and CBF/CRC values. The authors propose to treat symptomatic ICA stenosis and concurrent silent ipsilateral intracranial aneurysms at once if the patient is eligible for aneurysm surgery. CBF measurements should be performed before surgery. In a medically compromised patient carotid endarterectomy alone appears to be justifiable. In cases of symptomatic aneurysm and concurrent ICA stenosis a CEA can be added to aneurysm clipping to improve the hemodynamic situation for a better postoperative management. Xenon/CT investigations are suitable to provide important cerebral blood flow information. Together with angiography and clinical judgment it allows to identify patients with hemodynamic insufficiency. These are suitable candidates for an operative procedure to augment cerebral blood flow and to improve symptoms.     

A Case of Wallenberg's Syndrome Presenting with Spontaneous Thrombosis of a Vertebral Artery Aneurysm

Complete spontaneous thrombosis of intracranial aneurysms is uncommon. Although this type of thrombosis is largely asymptomatic, in rare cases it can be accompanied by parent artery occlusion and ischemic stroke. There are limited reports of complete thrombosis of an unruptured aneurysm of the internal carotid artery and middle cerebral artery. Furthermore, there are no reports of occlusion of the vertebral artery caused by thrombosis of an aneurysm. The mechanisms of spontaneous thrombosis are not established. However, aneurysm morphology, arteriosclerosis, and stagnation of aneurysm flow have been suggested. Herein, we present a novel case of Wallenberg's syndrome caused by a fusiform aneurysm in which complete thrombosis of the proximal vertebral artery occurred. We discuss the mechanisms of thrombosis caused by an unruptured aneurysm, which may be useful for managing such patients who present with transient ischemic attacks.     

Clinical and Angiographic Results after Treatment with Combined Clipping and Wrapping Technique for Intracranial Aneurysm

Objective

There have been numerous follow-up studies of patients who had ruptured or unruptured intracranial aneurysms treated by wrapping technique using various materials have been reported. Our objective was to ascertain whether our particular wrapping technique using the temporalis muscle provides protection from rebleeding and any aneurysm configuration changes in follow-up studies.

Methods

Clinical presentation, the location and shape of the aneurysm, outcomes at discharge and last follow-up, and any aneurysm configuration changes on last angiographic study were analyzed retrospectively in 21 patients. Reinforcement was acquired by clipping the wrapped temporalis muscle. Wrapping and clipping after incomplete clipping was also done. Follow-up loss and non-angiographic follow-up patient groups were excluded in this study.

Results

The mean age was 53 years (range 29-67), and 15 patients were female. Among 21 patients, 10 patients had ruptured aneurysms (48%). Aneurysms in 21 patients were located in the anterior circulation. Aneurysm shapes were broad neck form (14 cases), fusiform (1 case), and bleb to adjacent vessel (6 cases). Five patients were treated by clipping the wrapped temporalis, and 16 patients by wrapping after partial clipping. The mean Glasgow coma scale (GCS) at admission was 14.2. The mean Glasgow outcome scale (GOS) at discharge was 4.8, and 18 patients were grade 5. The mean period between initial angiography and last angiography was 18.5 months (range 8-44). Aneurysm size was not increased in any of these patients and configuration also did not change. There was no evidence of rebleeding in any of these treated aneurysms.

Conclusion

Our study results show that wrapping technique, using the temporalis muscle and aneurysm clip(s), for intracranial aneurysm treatment provides protection from rebleeding or regrowth.     

Flow diverters for treatment of intracranial aneurysms: Current status and ongoing clinical trials

The ultimate treatment goal for intracranial aneurysms is to reconstruct the vessel wall and correct the hemodynamic disturbance. A flow diverter is a stent placed in the parent artery to reduce blood flow in the aneurysm sac to the point of stagnation, gradual thrombosis, and neointimal remodeling to maintain outflow in the side branches and perforators. Here, we review the two commercially available flow diverters, the Pipeline Embolization Device (PED) and the SILK flow diverter (SFD). The rates of severe hemorrhagic complications have been reported to be 2% for the PED and 0.8% for the SFD. The results of studies completed thus far show that endovascular reconstruction with flow diverters is an effective treatment of wide-necked, fusiform, large, and giant unruptured intracranial aneurysms, with 5% to 10% of patients experiencing permanent major morbidity and mortality. The results of ongoing studies may resolve whether flow diverters can replace coil embolization for the treatment of all, or selected, intracranial aneurysms.     

床突旁颈内动脉瘤的手术治疗

探讨床突旁动脉瘤的分型，以及各型的手术特点，以提高该动脉瘤的手术疗效。回顾性分析ｐ－ＩＣＡＡ１８例，其中颈眼动脉型７例；垂体上动脉型７例；颈内动脉腹侧型４例。手术方法包括动动脉瘤夹闭术１３例交；动脉瘤孤立术３例；夹闭＋包裹术２例；颈总动有吉轧＋动脉瘤包裹１例。     

选择性血管结扎法建立大鼠脑动脉瘤模型

目的 探讨选择性血管结扎法对大鼠脑动脉瘤形成的影响.方法 SD大鼠50只,随机分为3组:(1)A组20只:结扎左侧颈总动脉+两侧肾动脉后支(各侧1支);(2)B组20只:"8"字形结扎左侧颈内、外动脉+电凝并切断两侧肾动脉(各侧只留1个分支);(3)C组为假手术组10只.术后喂养含0.9%的盐及0.12%β-氨基丙腈的饲料.4周后处死,取大鼠脑动脉Willis环,在光镜下观察其病理的变化.结果 A组大鼠ACA/OA分叉处均未见有进展期动脉瘤,仅3个早期动脉瘤样改变.B组大鼠中发现12个进展期动脉瘤和2个早期动脉瘤样改变.C组中未见动脉瘤形成.结论 血管壁结构的破坏或变弱和高血液动力学压力是动脉瘤形成的主要因素.