Fenestration of the middle cerebral artery and aneurysm at the site of the fenestration

Abstract

The authors report the case of a patient who presented a ruptured aneurysm of the anterior communicating artery and an unruptured aneurysm of the middle cerebral artery arising at the site of a fenestration of the MCA. The fenestration was undiagnosed on the preoperative angiogram but discovered during the surgery carried out for clipping of the aneurysms. In the literature, cases of fenestration of the MCA are sporadically reported and are incidental findings; an aneurysm may be associated on an artery other than the fenestrated MCA; an aneurysm arising at the site of the MCA fenestration is a very rare occurrence.     

Arterial fenestrations and their association with cerebral aneurysms

Fenestrations of intracranial arteries and associated aneurysms are rare. The significance of these fenestrations in relation to aneurysms remains unclear. We present four patients with fenestration-associated aneurysms and a comprehensive review of associations with aneurysms and other vascular lesions. A PubMed search of the literature was conducted from 1970–2012 reporting cases of intracranial aneurysms associated with arterial fenestration or duplications. Data were collected on patient presentation, sex, age, aneurysm and fenestration location, aneurysm treatment, and presence of other vascular lesions. We performed a retrospective review of four patients with intracranial fenestrations associated with aneurysms at our institution from 2012–2013. There were 59 cases of fenestrations and associated aneurysms in the literature. Aneurysms were reported as either arising from (n = 50) or adjacent to but distinct from (n = 13) fenestrations. The most common single fenestration location was at the basilar artery (n = 23, 36.5%); however the majority of fenestrations were in the carotid circulation (n = 34, 54.0%). The majority of patients with aneurysms and fenestrations at all locations except those at the anterior communicating artery (70.5%) presented with subarachnoid hemorrhage. Patients with aneurysms arising from a fenestration or adjacent to a fenestration presented with an additional intracranial vascular lesion in 38% and 31% of cases, respectively. The majority of all aneurysms were treated with microsurgical clipping. Aneurysms associated with cerebral arterial fenestrations are most commonly discovered after subarachnoid hemorrhage and are most often located in the carotid circulation. A high index of suspicion must be maintained for an associated vascular lesion if an intracranial fenestration is discovered.     

Fenestration of the middle cerebral artery and aneurysm at the site of the fenestration.

The authors report the case of a patient who presented a ruptured aneurysm of the anterior communicating artery and an unruptured aneurysm of the middle cerebral artery arising at the site of a fenestration of the MCA. The fenestration was undiagnosed on the preoperative angiogram but discovered during the surgery carried out for clipping of the aneurysms. In the literature, cases of fenestration of the MCA are sporadically reported and are incidental findings; an aneurysm may be associated on an artery other than the fenestrated MCA; an aneurysm arising at the site of the MCA fenestration is a very rare occurrence.     

Ruptured Saccular Aneurysm Arising from Fenestrated Proximal Anterior Cerebral Artery : Case Report and Literature Review

The aneurysm arising from fenestrated proximal anterior cerebral artery (ACA) is considered to be unique. The authors report a case of a 59-year-old woman who presented with a subarachnoid hemorrhage (SAH) secondary to a ruptured aneurysm originating from the fenestrated A1 segment of right ACA. The patient had another unruptured aneurysm which was located at the right middle cerebral artery bifurcation. She was successfully treated with surgical clipping for both aneurysms. From the previously existing literatures, we found 18 more cases (1983-2011) of aneurysms associated with fenestrated A1 segment. All cases represented saccular type of aneurysms, and 79% of the patients had SAH. There were three subtypes of the fenestrated A1 aneurysms depending on the anatomical location, relative to the fenestrated segment. The most common type was the aneurysms located on the proximal end of fenestrated artery (82%). Azygos ACA and hypoplastic A1 were frequently accompanied by the aneurysm (33% and 31%, respectively), and multiple aneurysms were shown in three cases (16%). Considering that fenestrated A1 segment is likely to develop an aneurysm, which has high risk of rupture, early management may benefit patients with aneurysms accompanied by fenestrated proximal ACA.     

三维CT血管造影对颅内动脉瘤夹闭术后的评价意义

目的 探索颅内动脉瘤夹闭术后方便、安全、可靠的评价方法 ,研究三维CT血管造影(3D-CTA)对术后评价的临床意义. 方法 回顾性分析我院自2006年1月至2007年3月收治颅内动脉瘤患者120例,显微手术夹闭52例,术后采用3D-CTA随访手术患者20例,其中多发动脉瘤1例,动脉瘤数21个(前交通动脉瘤11个,后交通动脉瘤7个,大脑中动脉M3段1个,脉络膜前动脉1个,大脑前动脉A1段起始部1个),随访2～38周,平均(15±11)周,观察术后瘤夹位置,载瘤动脉近段与远段通畅情况,瘤体及瘤颈残留等. 结果 3D-CTA显示动脉瘤夹位置良好19例,瘤央冈合并弹簧圈放射状伪影难以准确显示1例:载瘤动脉近段及远段通畅良好20例,可清楚分辨出瘤夹与载瘤动脉之间关系,未发现动脉瘤体残留. 结论 3D-CTA可作为动脉瘤夹闭术后随访评价的重要方法 ,具有重要的临床应用价值.     

Assessment of long-term results of intracranial aneurysm clipping by means of computed tomography angiography

Background and purposeThe aim of this retrospective study was to assess the effectiveness of aneurysm clipping by computed tomography angiography (CTA) in a long-term follow-up.Material and methodsThe CTA examination was performed in 119 patients who had 143 aneurysms clipped. The examinations were performed 3 to 11 years (mean 6 years) after clipping using a GE Lightspeed PRO16 scanner.ResultsIn all cases but one, good quality CTA images, suitable for evaluation of the arteries around the clip site, were obtained. Complete aneurysm closure without neck remnant or regrowth was confirmed in 137 (96%) aneurysms. In 4 (3%) cases, neck remnants were detected (2 on the anterior communicating artery [AComA] and 2 on the middle cerebral artery [MCA]). A total clip slippage from the aneurysm dome was revealed in 1 case. One case of aneurysm re-rupture was noted, 11 years after clipping. The rebleeding was caused by AComA aneurysm regrowth. Among these 6 patients with unsatisfactory clipping, 2 required further treatment and 4 remain under observation. Nineteen ‘de novo’ aneurysms in other locations were found in 14 (12%) patients. Summing up all of the pathological findings in the study group, there were 18 (15%) patients who needed further management including close surveillance or re-treatment.ConclusionsComputed tomography angiography is a simple and reliable method of aneurysm clipping evaluation. The long-term follow-up CTA confirmed the permanent and complete obliteration of 96% of the aneurysms. The rate of unsatisfactory aneurysm closure was 4%, but only 1.4% needed re-treatment during a mean follow-up of 6 years. The annual risk of aneurysm re-rupture was 0.1%.     

自发性蛛网膜下腔出血脑血管造影阴性的诊治对策

目的 探讨蛛网膜下腔出血(SAH)病人可能存在的出血原因，寻求当首次脑血管造影阴性时的诊治对策。方法 回顾性分析我科近5年来322例SAH出血病人，其中55例病人首次血管造影阴性。结果 17例因再出血或遵医嘱行2次脑血管造影，3例发现颅内动脉瘤，l例发现左颞叶底部脑动静脉畸形(AVM)。2例重复脑血管造影阴性行开颅手术探查，证实分别为前交通动脉瘤和左侧颈内动脉后交通动脉瘤；8例行MRI检查，1例发现胼胝体AVM；8例行CTA检查，1例发现前交通动脉瘤。1例因出现典型的下肢放射痛而行脊髓血管造影，发现L2AVM。结论 对于SAH后首次造影阴性的病人，应行重复血管造影，结合MRI、MRA及CTA检查可提高诊断率，必要时行手术探查。     

平板3D-DSA在前交通动脉瘤血管内治疗中的价值

目的评估平板3D-DSA在前交通动脉瘤血管内栓塞治疗中的应用价值。方法回顾性分析12例前交通动脉瘤行介入栓塞治疗的资料,常规全脑血管DSA检查后,再行三维重建,选择适合的栓塞材料及工作角度进行手术,并分析3D-DSA对介入栓塞治疗的应用意义。结果 8例动脉瘤100%栓塞,2例栓塞95%,1例栓塞90%,1例栓塞80%,急性脑血栓形成1例,血管痉挛2例,无动脉瘤破裂出血及死亡病例。结论 3D-DSA能够详细地显示前交通动脉瘤的解剖信息,可明确其诊断,对制定栓塞手术计划及介入治疗具有重要的临床应用价值。     

无蛛网膜下腔出血的破裂脑动脉瘤

目的 总结无蛛网膜下腔出血(SAH)的破裂脑动脉瘤的诊治经验.方法 对15例在起病后2 d内首次CT或MRI上表现为脑内出血(ICH),和(或)脑室内出血(IVH)、硬脑膜下血肿(SDH)和壁间出血(IMH)而无SAH的破裂脑动脉瘤患者的临床表现、影像学检查结果 、治疗方法 和预后进行回顾性分析.结果 本组首次CT或MRI检查表现为ICH者3例、IVH合并ICH者6例、SDH者1例、IVH者1例、IMH者3例和等高混合密度者1例.其中动脉瘤位于大脑中动脉6例、前交通动脉4例、后交通动脉3例、大脑前动脉1例和小脑后下动脉1例.开颅手术夹闭动脉瘤13例,血管内栓塞2例.出院时GOS评分:恢复良好8例、中残3例、重残3例和植物生存1例.本组15例占同期破裂脑动脉瘤的3.8%.结论 破裂脑动脉瘤首次CT扫描可表现为单纯ICH,和(或)IVH、SDH、IMH而无SAH,与CT扫描时间、动脉瘤的部位和指向以及出血量有关.早期控制颅内高压、及时诊断和有效处理破裂动脉瘤,是改善预后的关键.     

Congenital anomalies of cerebral artery and intracranial aneurysm]

It is well known that congenital anomalies such as polycystic kidney, aortic coarctation, Marfan syndrome, Ehler-Danlos syndrome are apt to be complicated by intracranial aneurysms. In this report we attempt to reveal the relation and incidence between cerebrovascular anomalies and intracranial aneurysms. The etiology of aneurysms has been discussed, too. 12 cases of persistent trigeminl artery, 2 cases of persistent hypoglossal artery and 11 cases of fenestration were obtained from 3841 patients who were angiographically examined in our clinic for 5 years. The incidence is 0.31%, 0.05% and 0.29%, respectively. Persistent trigeminal arteries were complicated by 2 cases of intracranial aneurysms and one case of arterivenous malformations (AVM), persistent hypoglossal arteries were complicated by one case of aneurysm, and fenestrations were complicated by 2 cases of aneurysms and one case of AVM. One case of congenital agenesis of right internal carotid artery was obtained which was complicated by aneurysm of anterior communicating artery. Totally, 8 cases of aneurysms and AVM were obtained from 26 cases of cerebrovascular anomalies (incidence 30.8%). On the other hand, thalamic or caudate hemorrhage revealed the highest incidence of complication of intracranial aneurysms among intracerebral hematomas (10.7%). Compared with the incidence of aneurysms between cerebro vascular anomalies (30.8%) and thalamic or caudate hemorrhage (10.7%), the difference is statistically signigicant (P less than 0.05). The cause of intracranial aneurysm has not yet been clarified. But it is well accepted that the defect of tunica media vasorum is most responsible factor as to the occurrence of intracranial aneurysms. We concluded that the genetic error of cerebral vessels including defect of media caused intracranial aneurysms, and this result was supported from the evidence that cerebrovascular anomalies showed statistically high incidence of complication of intracranial aneurysms.     

Contralateral Transradial Access for Coil Embolization of Distal Anterior Cerebral Artery Aneurysm Associated With a Steep Ipsilateral A1-A2 Angle

ObjectiveEndovascular treatment of distal anterior cerebral artery aneurysms is commonly addressed via the ipsilateral A1 segment of the anterior cerebral artery. However, when the parent pericallosal artery has a sharp ipsilateral A1-A2 angle, catheterization through the ipsilateral A1 segment can potentially result in vessel injury, catheter kinking, and/or compromised/stagnant anterior cerebral artery flow. Here, we present a case of a distal anterior cerebral artery aneurysm associated with a steep ipsilateral A1-A2 angle treated with contralateral transradial coil embolization.Case presentationA 91-year-old woman presented with a ruptured left distal anterior cerebral artery aneurysm at the A3 segment. The parent pericallosal artery had a steep ipsilateral A1-A2 angle. To safely achieve coil embolization of the aneurysm, a contralateral transradial system via the right A1 segment was employed. Although a secondary ipsilateral transradial system was required for contrast injection, aneurysm obliteration was successfully achieved without vessel injury or system instability.ConclusionThe A1-A2 angle can be a key anatomical factor in the endovascular treatment of distal anterior cerebral artery aneurysms. The contralateral transradial system is a useful treatment option for distal anterior cerebral artery aneurysms associated with sharp ipsilateral A1-A2 angles. However, if the distal anterior cerebral artery aneurysm cannot be clearly visualized through the contralateral system, an ipsilateral system will be required for contrast injection.     

CT血管造影诊断破裂脑动脉瘤

目的探讨运用CTA诊断破裂脑动脉瘤。方法对怀疑颅内动脉瘤破裂的40例病人施行CTA检查,采用Philips Tomoscan AVP1螺旋CT机,数据经计算机工作站处理后以最大密度投影重建(MIP)和表面遮盖法重建(SSD)法显示,由放射科医师和神经外科医师共同阅片。结果本组40例病人共检出25例28个动脉瘤,其中前交通动脉瘤13例,颈内动脉颅内段动脉瘤3例,后交通动脉瘤2例,大脑中动脉瘤2例,眼动脉瘤1例,基底动脉梭形动脉瘤1例,左侧大脑中动脉瘤破裂合并右侧颈内动脉瘤1例,后交通动脉瘤合并同侧颈内动脉床突周围段芽孢状微小动脉瘤2例。20例脑动脉瘤做了开颅手术治疗,其中15例单纯根据CTA检查结果手术,术中证实诊断。结论CTA具有快速、简便、安全、可靠的优点,可作为破裂脑动脉瘤和急诊手术前首选的检查。     

Familial Intracranial Aneurysms

Objective

Numerous studies have compared the characteristics of familial intracranial aneurysms with those of non-familial aneurysms. To better understand familial subarachnoid hemorrhage (SAH), we studied a series of patients with SAH who had at least one first-degree relative with SAH, and compared our results with those of previous studies.

Methods

We identified patients treated for SAH at our hospital between January 1993 and October 2006 and analyzed those patients with one or more first-degree relatives with SAH. We retrospectively collected data from patients with a family history and searched for patients who had relatives with aneurysms or who had been treated at other hospitals for SAH.

Results

We identified 12 patients from six families with at least two first-degree relatives with SAH. All patients had affected first-degree relatives; in five families, they were siblings. The mean age at the time of rupture was 49.75 years; in four families, the age difference was within 5 years. In five patients (42%), the aneurysm was located in the middle cerebral artery. Only one patient had an aneurysm in the anterior communicating artery.

Conclusion

In agreement with previous studies, our results showed that familial aneurysms, in comparison with non-familiar aneurysms, ruptured at a younger age and smaller size, had a high incidence in the middle cerebral artery, and were underrepresented in the anterior communicating artery. Interestingly, the age at the time of rupture was similar between relatives. Screening should be considered in the fifth or sixth decade for those who have a sibling with SAH.     

Ruptured Aneurysm Arising from the Distal End of a Proximal A1 Fenestration : Case Report and Review of the Literature

A 75-year-old female presented with subarachnoid hemorrhage. Angiography revealed a partial duplication (fenestration) in the proximal A₁ segment and a ruptured aneurysm at the distal end of A₁ fenestration. This congenital anomaly accompanying an aneurysm was associated with duplicated ipsilateral middle cerebral artery (MCA). Congenital defect of the arterial wall and hemodynamic factors at the fenestrated A₁ are considered to play a significant role in the development of this aneurysm. The present case is peculiar because not only the ruptured A₁ aneurysm was related with the anterior and middle cerebral artery duplication but also the location of A₁ fenestration and the origin of A₁ aneurysm in a fenestration are quite unusual.     

Transcranial Doppler detection of anterior cerebral artery vasospasm.

The performance of transcranial Doppler in the detection of anterior cerebral artery vasospasm and vasospasm in patients after subarachnoid haemorrhage was analysed. Transcranial Doppler and cerebral angiography were performed within the same 24 hours on each of 41 patients with acute subarachnoid haemorrhage. Sensitivity and specificity of transcranial Doppler to classify middle cerebral arteries, anterior cerebral arteries, and patients with angiographic vasospasm were determined at mean velocities of 120 and 140 cm/s. Accuracy of transcranial Doppler was better at 140 than at 120 cm/s. For the middle cerebral artery, sensitivity was 86%, specificity 98%. For the anterior cerebral artery, sensitivity was 13%, specificity 100%. Among all patients, sensitivity was 45%, specificity 96%. Among patients with anterior communicating artery aneurysms, sensitivity was 14%, specificity 90%. Therefore, transcranial Doppler accurately differentiates between middle cerebral arteries with and without vasospasm on angiography, but has a very low sensitivity for detecting anterior cerebral artery vasospasm and vasospasm in patients with anterior communicating artery aneurysms. Since vasospasm may involve anterior cerebral arteries while sparing middle cerebral arteries, especially after rupture of an anterior communicating artery aneurysm, caution should be exercised in using negative transcranial Doppler results to make treatment decisions based on the assumed absence of vasospasm.     

Flow diversion treatment of anterior communicating artery region aneurysms

Background and purposeReports on flow diversion treatment of aneurysms beyond the Circle of Willis are limited, with few series dedicated to anterior communicating artery region aneurysms. The purpose of this study is to evaluate the safety and effectiveness of the pipeline embolization device in the treatment of anterior communicating artery region aneurysms.Materials and methodsThe neuro-interventional database of a single institution was retrospectively reviewed for anterior communicating artery aneurysms treated with the pipeline embolization device between November 2016 and December 2018. Data on clinical presentation, aneurysm location, type, vessel size, procedural complications, clinical and imaging follow-up were analyzed.ResultsTen patients with 11 anterior communicating artery aneurysms were included. Procedural success was achieved in 9/10 patients (90%). Flow diversion with the pipeline embolization device yielded occlusion in 100% of patients at 6.5 months. Symptomatic ischemic complications occurred in 2/10 patients (20%); only one of who had permanent symptoms. Hemorrhagic groin complications were encountered in 2/10 patients (20%). There were no deaths and no cerebral hemorrhagic complications.ConclusionsFlow diversion therapy may provide a feasible solution for anterior communicating artery region aneurysms that are not amenable to traditional surgical or endovascular modalities.     

Cerebral aneurysms and variations in the circle of Willis

In order to obtain information about the relationship between variations in the circle of Willis and aneurysms, 44 complete circles of Willis with aneurysm were studied macroscopically. The incidence of variations was significantly higher in the aneurysm series than in the control circles without aneurysm. There was a definite correlation between asymmetric proximal segments of the anterior cerebral artery and aneurysms of the anterior communicating artery, and a tendency to correlation was found in the case of asymmetric posterior communicating arteries and aneurysms on the internal carotid artery-posterior communicating artery junction. In the light of these findings it seems likely that through hemodynamic changes variation in the circle of Willis plays some role in the development of cerebral aneurysms.     

Anterior communicating artery aneurysm associated with an infraoptic course of anterior cerebral artery and rare variant of the persistent trigeminal artery: a case report and literature review

Infraoptic course of the precommunicating segment of the anterior cerebral artery (A1) is a rare anomaly. Furthermore, the presence of this anomaly associated with persistent trigeminal artery variant has been reported in the literature only once. We present a patient who had infraoptic course of A1 associated with an ipsilateral persistent trigeminal artery variant arising from the right internal carotid artery with no apparent connection to the basilar artery. The persistent trigeminal artery variant supplied to the right posteroinferior cerebellar artery territory. The patient also had hypoplastic left vertebral artery, superior cerebellar arteries originating from posterior cerebellar arteries bilaterally, and a bilobed aneurysm of the anterior communicating artery. The aneurysm was clipped and the infraoptic course was verified during the surgery. The post-operative course was uneventful and a follow-up arteriogram on the 7th postoperative day revealed successful obliteration of the aneurysm.We reviewed the literature with respect to presentation, associated vascular anomalies, imaging, associated cerebral aneurysms and other cerebral abnormalities, and treatment of the associated aneurysms. A discussion of the embryogenesis of this rare anomaly is also provided.