Thromboembolic Events after the Coverage of Anterior Cerebral Artery with Flow Diversion: A Single Institution Series and Systematic Review.

BACKGROUND: Advances in the use of flow diversion (FD) now extend to bifurcation aneurysms; herein, we compare thromboembolic events in patients with ICA aneurysms treated with and without exclusion of the ACA. METHODS: Retrospective analysis of aneurysms in the terminal ICA treated with FD from 2013 to 2023 at a single-center. Procedures were classified according to the coverage at the origin of the ACA, and compared through bivariate-analysis. A review was also carried on PubMed, Web of Science, and EMBASE until April 2024, adhering to the PRISMA reporting guidelines. RESULTS: Ninety-five patients harboring 113 aneurysms treated in 102 procedures were evaluated. Fifty-eight were treated covering the ACA origin. Dual antiplatelet regimens included aspirin-clopidogrel (50%), aspirin-ticagrelor (44.1%), and aspirin-prasugrel (4.9%). Thromboembolic events occurred in six patients (5.9%), presenting with large vessel occlusion of the ICA, but without reaching statistical difference in the two treated cohorts (p=0.46). At a median clinical follow-up of 5.95 months, there were no differences in the functional outcomes in the two groups (p=0.22). Contralateral angiographic runs post-treatment after covering the ACA origin demonstrated increase in the A1 (median: 0.45mm; IQR=0.4-1.2) and ICA diameter (median: 0.55mm; IQR=0.1-1.2). After pooling data from literature and our cohort, complete side branch occlusion after the coverage of ACA was seen in 25% of branches (95%CI=0.16-0.36), and thromboembolic events were observed after 3% (95%CI=0.01-0.04) of procedures. CONCLUSION: Thromboembolic events can occur in distal ICA aneurysms treated with FD, but no significant association was seen with covering the ACA origin.

Triplicated middle cerebral arteries (duplicated and ipsilateral accessory) associated with triplicated anterior cerebral arteries (accessory) diagnosed by magnetic resonance angiography.

PURPOSE: To describe a case of duplicated middle cerebral artery (MCA) combined with ipsilateral accessory MCA, forming a triplicated MCA, associated with the accessory anterior cerebral artery (ACA), forming a triplicated A2 segment of the ACA detected incidentally on magnetic resonance (MR) angiography. METHODS: A 70-year-old woman with internal carotid artery (ICA) stenosis at the origin, which was detected by ultrasound, underwent cranial MR imaging and MR angiography of the intracranial region for an evaluation of brain and cerebral arterial lesions. The MR machine was a 3-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique. RESULTS: Multiple ischemic white matter lesions are observed. No significant stenotic lesions were observed in intracranial arteries. The right duplicated MCA was originated from right distal ICA. And main MCA was originated from right ICA bifurcation. Right accessory MCA was arisen from the A2 segment of the right ACA. Thus, the right MCA was triplicated. There was also an accessory ACA forming a triplicated ACA at its A2 segment. These findings were clearly identified on partial volume-rendering (VR) images. CONCLUSION: We herein report a case of triplicated MCA associated with triplicated ACA. MCA variations are relatively rare, and this is the third case of triplicated MCA reported in relevant English-language literature. To identify multiple cerebral arterial variations, creating partial VR images using MR angiographic source images is useful.

Validation of a Simplified Model for Subarachnoid Hemorrhage in Mice.

BACKGROUND: Subarachnoid hemorrhage (SAH) represents a severe injury to the brain and is associated with a high mortality (40%). Several experimental SAH models are described in the literature requiring specialized equipment and a high degree of surgical expertise. Our goal was to validate a simplified, cost-effective model to permit future studies of SAH. METHODS: SAH was induced by injection of homologous blood into the cisterna magna. Perfusion-fixation then perfusion of gelatinous India ink was performed. Brains and brainstems were collected and imaged for analysis of cerebral vasospasm. Triphenyl tetrazolium chloride (TTC) staining was used to analyze brain tissue cell death 24 hours following stroke. A composite neuroscore was utilized to assess SAH-related neurologic deficits. RESULTS: Anterior cerebral artery and basilary artery diameters were significantly reduced at 24 hours post SAH induction. Middle cerebral artery diameter was also reduced; however, the results were not significant. TTC staining showed no infarcted tissue. Neuroscores were significantly lower in the SAH mice, indicating the presence of functional deficits. CONCLUSIONS: This simplified model of SAH elicits pathological changes consistent with those described for more complex models in the literature. Therefore, it can be used in future preclinical studies examining the pathophysiology of SAH and novel treatment options.

Anterior Interhemispheric Approach for the Surgical Treatment of Azygos Anterior Cerebral Artery Aneurysms: A Case Series.

The azygos artery is an uncommon vascular variant of the anterior cerebral artery (ACA). This anomaly is associated in a high percentage with aneurysms. Management of azygos ACA aneurysms represents a surgical challenge. We present five patients who underwent microsurgical treatment for distal azygos ACA aneurysms with complex morphology. Four patients showed subarachnoid hemorrhage (SAH) and one complained of sentinel headache. Early preoperative digital subtraction angiography (DSA) or computerized tomography angiography (CTA) was performed. All patients were treated by surgical clipping via an anterior interhemispheric approach. During follow-up, all patients had a satisfactory outcome, with postoperative angiograms showing complete resolution of aneurysms.

Safety and anatomical outcome analysis after flow diverter coverage of the anterior cerebral artery.

OBJECTIVES: Few studies on ischemic complications and flow changes after a flow diverter covering the anterior cerebral artery. The purpose of the study was to explore the ischemic complications and anatomical alterations associated with the flow diverter after it covers the anterior cerebral artery. MATERIALS AND METHODS: In this single-center study, patients treated with FD covering the anterior cerebral artery at the First Affiliated Hospital of Zhengzhou University were retrospectively collected. The primary endpoint was ischemic complications related to the anterior cerebral artery. Secondary endpoints were anatomical changes in the anterior cerebral artery postoperatively and at follow-up. RESULTS: A total of 59 patients were included in this study. Four (6.8%) patients presented with ischemic stroke symptoms. Immediately after the procedure, complete occlusion of A1 and decreased blood flow was observed in 13 (22.0%) and 21 patients (35.6%), respectively. At follow-up, A1 artery was occluded in 34 patients (57.6%) and decreased blood flow was observed in 10 patients (16.9%). Symptoms of neurological deficits related to the anterior cerebral artery were not observed in all patients at follow-up. CONCLUSION: Coverage of A1 is safe, with a low incidence of ischemic stroke, when using an FD to treat aneurysms. Risk of reduced perfusion of the anterior cerebral artery postoperatively even if the anterior communicating artery is open. In cases with A1 occlusion, the blood flow in the distal the anterior cerebral artery can be adequately compensated by opening the anterior communicating artery and good vascular anastomoses.

Risk Factors for the Recurrence of Distal Anterior Cerebral Artery Aneurysms After Endovascular Treatment.

OBJECTIVE: We aimed to investigate risk factors for the recurrence of distal anterior cerebral artery (DACA) aneurysms after endovascular treatment (EVT). METHODS: The clinical and radiologic outcomes of DACA aneurysms treated with endovascular methods at a single tertiary hospital from September 2008 to December 2021 were retrospectively reviewed. We measured the angle between 2 distal branches of DACA aneurysms and categorized the angle as follows: 1) wide-angle (≥180°), and 2) narrow-angle type configuration (<180°). Univariate and multivariate analyses were performed to demonstrate the relationships between characteristics of DACA aneurysm and recurrence risk. RESULTS: In total, 132 DACA aneurysms were treated in our institution. Among these, 47 DACA aneurysms after EVT were included in this study. Forty patients underwent coil embolization without stent, 7 for stent-assisted coil embolization. At the last follow-up (mean 30.2 ± 24.2 months), overall recurrence rate was 23.4% (n = 11). Recurrence rate of the wide-angle type (9 of 23, 39.1%) was significantly greater than narrow-angle type (2 of 24, 8.3%) (P = 0.041; odds ratio 8.174, 95% confidence interval 1.094-61.066). Irregular shape of the DACA aneurysm also showed significantly greater recurrence rate (P = 0.011; odds ratio 10.663, 95% confidence interval 1.701-66.838) after endovascular treatment. CONCLUSIONS: The wide-angle between 2 distal branches of DACA aneurysm and irregular shape might be independent risk factors for the recurrence after endovascular treatment for DACA aneurysms.

The interpositional bypass with a parietal branch of superficial temporal artery graft for symptomatic atherosclerotic anterior cerebral artery stenosis or occlusion.

Background: For nonmoyamoya patients with anterior cerebral artery (ACA) stenosis or occlusion, whether direct revascularization of the ACA territory can prevent stroke is still unclear. The objective of this study was to investigate the efficacy and safety of a parietal branch of superficial temporal artery-interposed superficial temporal artery-to-ACA bypass (PISAB) for preventing stroke in patients with symptomatic atherosclerotic ACA stenosis or occlusion (SAASO). Methods: We retrospectively analyzed the data from patients with SAASO who had undergone PISAB in our center between April 2016 and November 2021. The rates of patency, satisfaction (revascularization grades A and B) of bypass, perioperative complications, recurrence of ischemic stroke, changes in bypass flow, and improvements in cerebral blood perfusion were analyzed. Results: A total of 19 SAASO patients were involved in this study. Sixteen out of 19 (84.2%) patients were free from any cerebral ischemic events after surgery. Only 3 patients (15.8%) had recurrent stroke postoperatively. Two (10.5%) surgery-related complications occurred, including hyperperfusion syndrome and minor stroke. No skin ischemic complications occurred. The average follow-up period was 50.6 ± 18.3 months. The flow rate of the bypass was significantly increased half a year after surgery (56.2 ± 8.0 mL/min vs. 44.3 ± 5.3 mL/min, p < 0.001). The ratio of ipsilateral/contralateral mean transit time in the superior frontal gyrus was decreased significantly after bypass (1.08 ± 0.07 vs. 1.23 ± 0.05, p < 0.001) and continued to decrease 6 months after surgery (1.05 ± 0.04 vs. 1.08 ± 0.07, p = 0.002). The patency rate of PISAB was 94.7% (18/19) 2 years after surgery. The satisfaction rate of bypass was 89.5% (17/19). Conclusion: The results of this study indicate that PISAB, as a safe superficial bypass, can effectively reduce the risk of stroke in SAASO patients. More precise conclusions will require randomized control studies.

Effect of Physiotherapy on an Elderly Patient With Distal Anterior Cerebral Artery Aneurysm Clipping.

This case study analyzes the effectiveness of physiotherapy in the treatment of a female patient, aged 65 years, with hypertension who had a history of subdural hematoma (SDH) secondary to a distal anterior cerebral artery (DACA) aneurysm rupture. For that, she underwent DACA aneurysm clipping surgery and developed a disability on the right side of her body. The patient had diminished functional independence, weak muscles, and restricted mobility when she first arrived. A thorough physiotherapy program was developed with the goals of increasing mobility, building independence in daily living tasks, and improving motor function. Adapted to the patient's particular requirements and limits, the intervention included therapeutic exercises, gait training, balancing exercises, and functional training. Assessments were carried out on a regular basis to track improvement and modify the treatment plan as necessary. The patient's motor function, mobility, and functional independence were significantly improved during the intervention. Physiotherapy played a crucial role in significantly improving the patient's recovery, quality of life, and right-side disability following the DACA aneurysm clipping surgery. The presented case study clearly highlights the value of early and focused physiotherapy intervention in the effective management of neurological impairments and in achieving better rehabilitation outcomes in patients with similar medical presentations.

A primer to vascular anatomy of the brain: an overview on anterior compartment.

PURPOSE: Knowledge of neurovascular anatomy is vital for neurosurgeons, neurologists, neuro-radiologists and anatomy students, amongst others, to fully comprehend the brain's anatomy with utmost depth. This paper aims to enhance the foundational knowledge of novice physicians in this area. METHOD: A comprehensive literature review was carried out by searching the PubMed and Google Scholar databases using primary keywords related to brain vasculature, without date restrictions. The identified literature was meticulously examined and scrutinized. In the process of screening pertinent papers, further articles and book chapters were obtained through analysis and additional assessing of the reference lists. Additionally, four formalin-fixed, color latex-injected cadaveric specimens preserved in 70% ethanol solution were dissected under surgical microscope (Leica Microsystems Inc, 1700 Leider Ln, Buffalo Grove, IL 60089 USA). Using microneurosurgical as well as standard instruments, and a high-speed surgical drill (Stryker Instruments 1941 Stryker Way Portage, MI 49002 USA). Ulterior anatomical dissection was documented in microscopic images. RESULTS: Encephalic circulation functions as a complex network of intertwined vessels. The Internal Carotid Arteries (ICAs) and the Vertebral Arteries (VAs), form the anterior and posterior arterial circulations, respectively. This work provides a detailed exploration of the neurovascular anatomy of the anterior circulation and its key structures, such as the Anterior Cerebral Artery (ACA) and the Middle Cerebral Artery (MCA). Embryology is also briefly covered, offering insights into the early development of the vascular structures of the central nervous system. Cerebral venous system was detailed, highlighting the major veins and tributaries involved in the drainage of blood from the intracranial compartment, with a focus on the role of the Internal Jugular Veins (IJVs) as the primary, although not exclusive, deoxygenated blood outflow pathway. CONCLUSION: This work serves as initial guide, providing essential knowledge on neurovascular anatomy, hoping to reduce the initial impact when tackling the subject, albeit the intricate vasculature of the brain will necessitate further efforts to be conquered, that being crucial for neurosurgical and neurology related practice and clinical decision-making.

Reading and writing from right to left after anterior cerebral artery stroke.

This is the case report of a woman who started to write and read from right to left after anterior cerebral artery stroke, affecting the left supplementary motor area. No cases were found in the literature with exactly the same characteristics. She has been able to read and write faster after rehabilitation approach at Sarah Network of Rehabilitation Hospitals, in the Belo Horizonte city unit, Brazil, despite the maintenance of the inversion. She returned to her previous activities in an adaptive way. It was discussed how the dysfunction in this cerebral area and its connections may disturb the reading strategy and direction.

Relato do caso de uma mulher que passou a escrever e ler da direita para a esquerda após um acidente vascular encefálico isquêmico de artéria cerebral anterior, acometendo área motora suplementar esquerda. Não foram encontrados casos na literatura exatamente com as mesmas características. Durante a participação da paciente no programa de reabilitação neurológica da Rede Sarah de Hospitais de Reabilitação, unidade Belo Horizonte, foram observados ganhos na agilidade de leitura e escrita, ainda que mantendo a inversão, e retorno às suas atividades de forma adaptada. Realizou-se discussão de como o comprometimento dessa área e de suas conexões pode perturbar a estratégia de leitura e sua direção.

Flow Diversion as a Definitive Treatment for Recurrently Ruptured A1-A2 Anterior Cerebral Artery Aneurysm Following Clipping and Coiling.

Even after clipping of intracranial aneurysms, patients may experience incomplete occlusion or the future recurrence of their treated aneurysm. This paper presents a distinctive case of a recurrent A1-A2 anterior cerebral artery aneurysm that underwent four interventions over 16 years. The aneurysm was treated with two clippings, subsequent coiling, and flow diversion for definitive treatment. The challenges encountered in managing bifurcation aneurysms are discussed, emphasizing the importance of considering hemodynamic factors, vessel geometry, and recurrence risk factors in treatment decisions. The case highlights the need for closer follow-up of ruptured bifurcation aneurysms due to the higher likelihood of recurrence. The role of flow diverters in reinforcing vessel anatomy and preventing recurrence is also highlighted.

Exploring the anatomical configurations of the cerebral arteries in a cohort of South African patients.

The cerebral arteries, specifically the anterior cerebral artery (ACA) and posterior cerebral artery (PCA), work together with the smaller calibre arteries to provide effective communication between the anterior and posterior circuits of the brain via the circle of Willis (CoW). Morphologic variations of the cerebral arteries and the CoW may alter blood flow to the brain, resulting in intracranial vascular disorders associated with stroke, and aneurysms. This study aimed to document the morphology of the cerebral arteries and the CoW in the South African population. Two hundred and thirty-nine computed tomography angiography scans were assessed. Cerebral arteries and CoW normal morphology and variations were classified as complete, absent, or hypoplastic. The ACA A1 was absent in 4.91%, hypoplastic in 30.40%, fenestrated in 1.06%, and typical in 63.6%. The ACA A2 was absent in 0.42%, hypoplastic in 26.28%, and typical in 69.44%. We found triple ACA A2 in 2.98%, azygos in 1.28% and fenestrated in 1.28%. The middle cerebral artery (MCA) was hypoplastic in 7.35% and typical in 92.64%. The PCA was hypoplastic in 28.74% and typical in 71.25%. Knowledge of the configuration of the CoW plays a significant role in guiding therapeutic decision-making in treating various neurovascular pathologies.

The Anatomical Variation of the Distal Anterior Cerebral Artery: An Angiographic Study in a Greek Population Sample.

Objective The current retrospective angiographic study establishes the rates of variants in the distal anterior cerebral artery (DACA) in a sample of the Greek population. Methods Data were collected from 456 patients who underwent two-dimensional (2D) or three-dimensional (3D) digital subtraction angiography (DSA) of the carotid and vertebral arteries bilaterally. The study focused on patients with good visualization of the anterior and posterior circulations and employed magnetic resonance (MR) or computed tomography (CT) angiography for 3D reconstruction. The anterior cerebral artery (ACA) was classified into one of its two basic configurations, that is, with or without the callosomarginal artery (CMA). The bihemispheric, median, and azygos ACA patterns were also identified. Results The majority (373/456, 81.8%) exhibited a typical DACA pattern. The bihemispheric, median, and azygos patterns were identified in 66/456 (14.5%), 10/456 (2.2%), and 7/456 (1.5%), respectively. The CMA was present in 824/912 (90.4%) of the hemispheres, with a trend toward male predominance for bilateral presence (males: 167/192, 86.98%; females: 210/264, 79.55%; p = 0.05). In particular, the CMA was present significantly more frequently (p = 0.002) in the left hemispheres of male patients. Gender differences in CMA presence persisted in the analysis of the patients with a typical DACA pattern. Conclusion This study provides insights into the variations of the DACA in the Greek population. The observed gender differences in CMA rates suggest potential morphological variations in cerebral vasculature between males and females and contribute to a better understanding of vascular anatomy for clinical and surgical applications.

Management of patients with a neurovascular conflict involving the optic nerve and a non-diseased intracranial artery: Three cases.

Introduction: Determining whether a neurovascular conflict (NVC) involving the anterior visual pathway (AVP) and a non-diseased intracranial artery is amenable for microvascular decompression is challenging. Moreover, it is unclear whether microvascular decompression of the optic nerve is an effective therapy. Research question: What are the outcomes of different treatment strategies for NVCs involving the AVP and a non-diseased intracranial artery? Material and methods: Data on patients with symptomatic NVCs involving the AVP and a non-diseased intracranial artery was collected and included treatment and outcome parameters. The case series was drafted in accordance with the CARE guidelines. Results: Three patients aged 53,53 and 55 visited our out-patient clinic with a suspected symptomatic NVC between the optic nerve and a non-diseased intracranial artery. A conservative treatment was opted for in the first patient aimed at treating her glaucoma, with temporary improvement of symptoms. Microvascular decompression of the optic nerve was performed in two patients. One operated patient developed post-operative complications resulting in posterior circulation perfusion decline, while the other experienced a worse tunnel vision with a decrease in visual acuity. Discussion and conclusion: The diagnosis of a symptomatic NVC between the AVP and a non-diseased intracranial artery should be considered with caution, i.e. after exclusion of all other causes. Microvascular decompression can be performed but does not necessarily improve symptoms. A better understanding of the pathophysiological mechanisms underlying these NVCs is warranted to determine the benefit of microvascular decompression of the optic nerve.

Isolated anterior cerebral artery occlusion: an atypical form of moyamoya disease.

BACKGROUND: The relationship between anterior cerebral artery (ACA) occlusion and moyamoya disease (MMD) has rarely been studied. In this study, we focused on a special type of MMD: isolated ACA-occlusive MMD. We investigated clinical attributes, genotypes and progression risk factors in patients with ACA-occlusive MMD, providing initial insights into the relationship between ACA occlusion and MMD. METHODS: We retrospectively analysed digital subtraction angiography (DSA) from 2486 patients and diagnosed 139 patients with ACA-occlusive MMD. RNF213 p.R4810K (rs112735431) mutation analysis was performed. Patients were categorised into progression and non-progression groups based on whether they progressed to typical MMD. Differences in clinical characteristics, neuropsychological assessment, radiological findings and genotypes were evaluated. Logistic regression analyses identified risk factors for ACA-occlusive MMD progression. RESULTS: The median age of patients with ACA-occlusive MMD was 36 years, and the primary symptom was transient ischaemic attack (TIA). 72.3% of ACA-occlusive MMD patients had cognitive decline. Of 116 patients who underwent RNF213 gene mutation analysis, 90 patients (77.6%) carried the RNF213 p.R4810K GG allele and 26 (22.4%) carried the GA allele. Of 102 patients with follow-up DSA data, 40 patients (39.2%) progressed. Kaplan-Meier curve estimates indicated a higher incidence of ischaemic stroke in the progression group during follow-up (p=0.035). Younger age (p=0.041), RNF213 p.R4810K GA genotype (p=0.037) and poor collateral compensation from the middle cerebral artery (MCA) to ACA (p<0.001) were risk factors of ACA-occlusive MMD progression to typical MMD. CONCLUSIONS: Cognitive decline and TIA might be the main manifestations of ACA-occlusive MMD. Isolated ACA occlusion may be an early signal of MMD. The initial lesion site of MMD is not strictly confined to the terminal portion of the internal carotid artery. Younger patients, patients with RNF213 p.R4810K GA genotype or those with inadequate MCA-to-ACA compensation are more likely to develop typical MMD.

Cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion: A case report.

Cerebral hyperperfusion syndrome is a rare but serious complication after revascularization procedures for cerebrovascular diseases. Cerebral hyperperfusion syndrome can develop after treatment of acute ischemic stroke, including intravenous thrombolysis and endovascular treatment of large vessel occlusion. However, to the best of our knowledge, there are no previous reports describing cerebral hyperperfusion syndrome after endovascular treatment of medium vessel occlusion (eg, anterior cerebral artery A2/3 segment). We report a case of cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion. A 70-year-old woman with a history of hypertension and dyslipidemia was transferred by ambulance to our hospital because of immobility and slurred speech. She had mild right lower extremity paralysis, and her symptoms appeared improved compared with onset. She was diagnosed with cerebral infarction in the left frontal lobe. After hospitalization, her neurological symptoms worsened and she was referred to our department. We performed endovascular reperfusion therapy for left anterior cerebral artery A2 occlusion. Recanalization was achieved with residual stenosis. Despite the lack of complications associated with the procedure, the patient had prolonged disorientation, severe hemiplegia, and aphasia. Arterial spin labeling demonstrated hyperperfusion in the left anterior cerebral artery area. The symptoms gradually improved under strict blood pressure control. This report provides evidence that cerebral hyperperfusion syndrome can occur even after endovascular treatment for medium vessel occlusion. Arterial spin labeling was useful in detecting hyperperfusion.

Rupture Risk Factors and Strategies for Unruptured Distal Anterior Cerebral Artery Aneurysms.

BACKGROUND: Distal anterior cerebral artery (dACA) aneurysms are rare. Ruptured dACA aneurysms typically present with subarachnoid hemorrhage in conjunction with intracerebral hematoma and cause neurological deterioration. This study aimed to determine their risk of rupture and examine associated factors. METHODS: We retrospectively analyzed patients with dACA aneurysms to compare patient and aneurysm characteristics between ruptured and unruptured aneurysms. Clinical outcome was used the modified Rankin scale. Univariate analyses were performed to identify rupture risk factors. RESULTS: One hundred three patients with dACA aneurysms were examined (51 ruptured and 52 unruptured). The median aspect ratio of ruptured and unruptured aneurysms was 1.69 and 1.22, respectively (P < 0.01). The median maximum diameter of ruptured and unruptured aneurysms was 5.2 and 3.1 mm, respectively (P < 0.01). The median size ratio of ruptured and unruptured aneurysms was 3.32 and 2.17, respectively (P < 0.01). Maximum diameter was <5 mm in 45.2% of ruptured dACA aneurysms. dACA aneurysm, showing size ratio >2.4 and aspect ratio >1.4, had ruptured in 71.4% and 78.6%, respectively. We suggested that these are the threshold of size ratio and aspect ratio for rupture of dACA aneurysms. A total percentatge of 78.1% of aneurysms with aspect ratio >1.4 and size ratio >2.4 had ruptured. CONCLUSIONS: Distal anterior cerebral artery (dACA) aneurysms may rupture, even when small. We found a significant difference between ruptured and unruptured aneurysms with respect to maximum diameter, aspect ratio, and size ratio. Treatment for small aneurysms should be considered based on size ratio and aspect ratio, not just size.

Azygos anterior cerebral artery shield masquerading as an aneurysm.

Here, we describe a case of a woman suspected to have an anterior cerebral artery (ACA) aneurysm that was ultimately found to have an azygous ACA shield. This benign entity highlights the importance of thorough investigation with cerebral digital subtraction angiography (DSA). This 73-year-old female initially presented with dyspnea and dizziness. CT angiogram of the head suggested an incidental 5 mm ACA aneurysm. Subsequent DSA demonstrated a Type I azygos ACA supplied by the left A1 segment. Also noted was a focal dilatation of the azygos trunk as it gave rise to the bilateral pericallosal and callosomarginal arteries. Three-dimensional visualization demonstrated a benign dilatation secondary to the four vessels branching; no aneurysm was noted. Incidence of aneurysms at the distal dividing point of an azygos ACA ranges from 13% to 71%. However, careful anatomical examination is imperative as findings may be a benign dilatation for which case intervention is not indicated.

Anatomical Variations and Anomalies of the Anterior Communicating Artery Complex.

BACKGROUND: Intracranial arteries have a high rate of variation, but a clear schematic overview is lacking. In this pictorial review we classify and depict all variations and anomalies within the anterior communicating artery complex. METHODS: PubMed was searched with the terms "Anterior Communicating Artery" AND "Variations" OR "Anomalies." Articles were selected based on their description of variants. Cross-referencing was used to broaden the range of variations. Surgical view during pterional craniotomy and transsylvian approach was used as a baseline for schematic drawings of the variations. RESULTS: A total of 42 variants were identified, schematically drawn and classified into A1-A2 segment, anterior communicating artery, and the recurrent artery of Heubner. CONCLUSIONS: The anterior communicating artery complex consists of the anterior cerebral artery, anterior communicating artery and the recurrent artery of Heubner. An overview of these variations may be helpful in distinguishing pathology from anatomical variations, assist neurosurgeons during clipping of cerebral aneurysms, and support interventional radiologists during endovascular treatments. This article summarizes the current knowledge of anatomical variations within the anterior communicating artery complex, their prevalence and clinical relevance. A total of 42 variants were identified and schematically depicted. We encourage all who diagnose, treat, and study the anterior communicating artery complex to use this overview for a uniform and better understanding of its anatomy.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review.

Fusiform aneurysms of the anterior cerebral artery (ACA) are uncommon, and the natural history of this entity is poorly characterized. Along with our center experience, we conducted a systematic literature review to help shed light on the clinical course of ACA fusiform aneurysms. We queried our institutional database to identify cases with fusiform aneurysms of ACA. In addition, following the PRISMA algorithm, we identified all reported cases published in the English literature from the inception of PubMed until December 2022. We categorized clinical presentations into three categories: (i) traumatic/iatrogenic, (ii) spontaneous symptomatic ruptured/unruptured, and (iii) spontaneous asymptomatic aneurysms. We utilized descriptive statistics. We identified seven cases from our center along with 235 patients from published literature. Blunt trauma was responsible for the development of 19 aneurysms. Sixty-three percent of these aneurysms tend to rupture within 2 weeks from the initial trauma, and despite treatment, only 74% of these patients had good clinical outcomes. Spontaneous symptomatic presentation occurred in 207 patients and was often associated with previous/concomitant ACA dissection. Subarachnoid hemorrhage from ruptured aneurysms was the most common presentation. Spontaneous symptomatic fusiform aneurysm is rapidly evolving lesions, and treatment is necessary. Three of our own cases were treated with an endovascular flow diverter (pipeline) stenting with good outcomes. Spontaneous asymptomatic aneurysms were reported in nine patients. These lesions are often associated with other vascular abnormalities. Treatment included surgical clipping with good clinical outcomes. Instead, four patients from our center database were managed conservatively with equally good outcomes. Our study demonstrates good clinical outcomes when fusiform aneurysms of ACA, especially when symptomatic, are treated promptly with either reconstructive or deconstructive therapies.