Clipping of Anterior Circulation Aneurysms: Operative Instructions and Safety Rules for Young Cerebrovascular Surgeons.

INTRODUCTION: Due to the constant development of the technique, in the last 30 years, the endovascular treatment of the intracranial aneurysms (IAs) has gradually superseded the traditional surgery in the majority of centers. However, clipping still represents the best treatment for some anterior circulation IAs according to their angioarchitectural, topographical, and hemodynamic characteristics. Thus, the identification of residual indications for clipping and the maintenance of training programs in vascular neurosurgery appear nowadays more important than ever. MATERIALS AND METHODS: We reviewed our last 10-year institutional experience of ruptured and unruptured IAs clipping. We appraised in detail all technical refinements we adopted during this time span and analyzed the difficulties we met in teaching the aneurysm clipping technique to residents and fellows. Then, we described the algorithm of safety rules we used to teach young neurosurgeons how to surgical approach anterior circulation IAs and develop a procedural memory, which may intervene in all emergency situations. RESULTS: We identified seven pragmatic technical key points for clipping of the most frequent anterior circulation IAs and constructed a didactic approach to teach young cerebrovascular surgeons. In general, they concern craniotomy; cisternostomy; obtaining proximal control; cranial nerve, perforator, and vein preservation; necessity of specific corticectomy; aneurysm neck dissection; and clipping. CONCLUSION: In the setting of an IA clipping, particularly when ruptured, the young cerebrovascular surgeon needs to respect an algorithm of safety rules, which are essential not only to avoid major complications, but they may intervene during the difficulties helping to manage potentially life-tethering conditions.

Neuropsychological outcomes in patients with ruptured anterior communicating artery aneurysms treated by clipping versus coiling: a systematic review and meta-analysis.

Ruptured anterior communicating artery (ACoA) aneurysms are frequently associated with neuropsychological deficits. This review aims to compare neuropsychological outcomes between surgical and endovascular approaches to ACoA. We systematically searched PubMed, Embase, and Web of Science for studies comparing the endovascular and surgical approaches to ruptured ACoA aneurysms. Outcomes of interest were the cognitive function, covered by memory, attention, intelligence, executive, and language domains, as well as motor and visual functions. Nine studies, comprising 524 patients were included. Endovascularly-treated patients showed better memory than those treated surgically (Standardized Mean Difference (SMD) = -2; 95% CI: -3.40 to -0.61; p < 0.01). Surgically clipped patients had poorer motor ability than those with coiling embolization (p = 0.01). Executive function (SMD = -0.20; 95% CI: -0.47 to 0.88; p = 0.55), language (SMD = -0.33; 95% CI: -0.95 to 0.30; p = 0.30), visuospatial function (SMD = -1.12; 95% CI: -2.79 to 0.56; p = 0.19), attention (SMD = -0.94; 95% CI: -2.79to 0.91; p = 0.32), intelligence (SMD = -0.25; 95% CI: -0.73 to 0.22; p = 0.30), and self-reported cognitive status (SMD = -0.51; 95% CI: -1.38 to 0.35; p = 0.25) revealed parity between groups. Patients with ACoA treated endovascularly had superior memory and motor abilities. Other cognitive domains, including executive function, language, visuospatial function, attention, intelligence and self-reported cognitive status revealed no statistically significant differences between the two approaches. Trial Registration PROSPERO (International Prospective Register of Systematic Reviews) CRD42023461283; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=461283.

Letter to editor : optimizing surgical approaches for anterior communicating artery aneurysms: development and internal validation of a novel surgical scoring system.

The recent publication titled "Optimizing Surgical Approaches for Anterior Communicating Artery Aneurysms: Development and Internal Validation of a Novel Surgical Scoring System" presents a groundbreaking study in neurosurgery. This critique examines both the positive and negative impacts of the research. Positive aspects include the potential to improve patient outcomes through personalized surgical approaches guided by a standardized scoring system. Internal validation enhances the credibility of the scoring system. However, challenges such as the need for external validation and additional surgeon training are acknowledged. Overall, while the study offers promising advancements, further research and validation are essential for widespread implementation in clinical practice.

Risk factor analysis of changes in blood flow in the A1 segment of the anterior cerebral artery after flow-diverter coverage of it.

Few studies have explored the effect of a flow-diverter device (FD) on blood flow in the A1 segment of the anterior cerebral artery (ACA), after treatment of intracranial aneurysms in the bifurcation region of the internal carotid artery (ICA). The main objective of this article is to investigate the factors that affect A1 blood flow after FD covers the A1 artery. This is a single-center, retrospective study. Data were collected retrospectively from our center, and patients whose FDs were placed for treatment from the terminal of the ICA to the M1 segment were analyzed. A total of 42 patients were included in the study. Immediate post-procedural angiography following device placement revealed decreased blood flow in the A1 of 15 (35.7%) patients and complete occlusion of the A1 segment in 11 (26.2%) patients. During an average follow-up period of 9.8 months, the A1 segment was ultimately occluded in 25 patients (59.5%) and decreased blood flow in 4 patients (9.5%). When using FD to cover the A1 artery for the treatment of intracranial aneurysms, patients with preoperative opening of the anterior communicating artery (AcomA) are more prone to occlusion or decreased blood flow of the A1 artery, compared to patients without opening.

Anterior interhemispheric vs. pterional approach in the microsurgical management of anterior communicating artery aneurysms: a comparative analysis employing a novel multidimensional matching-tool.

The surgical management of anterior communicating artery aneurysms (AcomA) is challenging due to their deep midline position and proximity to complex skull base anatomy. This study compares the pterional craniotomy with the interhemispheric approach based on the specific aneurysm angulation. A total of 129 AcomA cases were analyzed, with 50 undergoing microsurgical clipping via either the pterional or interhemispheric approach. All selected cases had computed tomography-angiography with sagittal imaging slices and 2D-angiography. Using an interactive tool, 14 cases treated via the interhemispheric approach were matched with 14 cases approached pterionally based on clinical and morphological parameters, emphasizing intracranial aneurysm (IA) dome angulation relative to the frontal skull base. Outcomes included IA occlusion, temporary clipping incidence, intraoperative rupture, postoperative strokes, hemorrhages, hydrocephalus, vasospasm, and patient functionality. Matched cohorts had consistent demographics. Both approaches resulted in similar IA occlusion rates, but the interhemispheric approach led to improved clinical outcomes, measured by the modified Rankin Scale. It also had a lower incidence of hydrocephalus and reduced need for permanent ventriculoperitoneal shunt placement. Vasospasms and postoperative infarction rates were comparable between the groups. Our findings suggest potential advantages of the interhemispheric approach in managing AcomA, depending on aneurysm angulation. Despite a small sample size, the results highlight the importance of customized surgical decision-making based on the unique traits of each aneurysm and the surgeon's expertise.

Unveiling rupture risk and clinical outcomes in midline aneurysms: A matched cohort analysis investigating the impact of localization within the anterior or posterior circulation.

Intracranial aneurysms (IAs) located in the anterior and posterior circulations of the Circle of Willis present differential rupture risks. This study aimed to compare the rupture risk and clinical outcomes of anterior communicating artery aneurysms (AcomA) and basilar tip aneurysms (BAs); two IA types located along the midline within the Circle of Willis. We retrospectively collected data from 1026 patients presenting with saccular IAs. Only AcomA and BAs with a 3D angiography were included. Out of 186 included IAs, a cohort of 32 BAs was matched with AcomA based on the patients' pre-existing conditions and morphological parameters of IAs. Clinical outcomes, including rupture risk, hydrocephalus development, vasospasm incidence, and patients' outcome, were compared. The analysis revealed no significant difference in rupture risk, development of hydrocephalus, need for ventricular drainage, or vasospasm incidence between the matched AcomA and BA cohorts. Furthermore, the clinical outcomes post-rupture did not significantly differ between the two groups, except for a higher Fisher Grade associated with BAs. Once accounting for morphological and patient factors, the rupture risk between AcomA and BAs is comparable. These findings underscore the importance of tailored management strategies for specific IA types and suggest that further investigations should focus on the role of individual patient and aneurysm characteristics in IA rupture risk and clinical outcomes.

Fenestrated clipping of previously coiled posterior-superiorly projecting anterior communicating artery aneurysms: How I do it.

BACKGROUND: Anterior communicating artery (ACOM) aneurysms are among the most common aneurysms associated with aneurysmal subarachnoid hemorrhage (International Study of Unruptured Intracranial Aneurysms I (N Engl J Med 339:1725-1733, 1998), Wiebers (Lancet 362:103-110, 2003)). Surgical clipping of posterior-superiorly projecting ACOM aneurysms can be challenging, as the ipsilateral A2 can interfere with clip trajectory and ACOM perforating vessels obstructed from view. Intraluminal coils can further increase the difficulty of the procedure. METHOD: The relevant surgical anatomy with illustration is presented. A video detailing our technique on an illustrative case is provided. CONCLUSION: Surgical clipping of posterior-superiorly projecting ACOM aneurysms can require complex clip configurations. We describe the key steps of posterior-superiorly projecting ACOM aneurysm clipping through a lateral supraorbital craniotomy and fenestrated tandem clipping.

The anterior communicating artery variants: a meta-analysis with a proposed classification system.

Morphological and morphometric variants of the anterior communicating artery (AComA) have been described by multiple studies; however, a complete classification system of all possible morphological variants with their prevalence is lacking. The current systematic review with meta-analysis combines data from different databases, concerning the AComA morphological and morphometric variants (length and diameter). Emphasis was given to the related clinical implications to highlight the clinical value of their knowledge. The typical AComA morphology occurs with a pooled prevalence (PP) of 67.3%, while the PP of atypical AComA is 32.7%. The identified AComA morphological variants (artery's hypoplasia, absence, duplication, triplication, differed shape, fenestration, and the persistence of a median artery of the corpus callosum- MACC) were classified in order of frequency. The commonest presented variants were the AComA hypoplasia (8%) and the anterior cerebral artery (ACA) fusion (5.9%), and the rarest ones were the MACC persistence (2.3%), and the AComA triplication (0.7%). The knowledge of those variants is essential, especially for neurosurgeons operating in the area. Given the high prevalence of AComA aneurysms, an adequate and complete classification of those variants is of utmost importance.

Morphology and morphometry of the anterior cerebral-anterior communicating artery complex.

PURPOSE: The variations of Cerebral arterial circle (Circle of Willis) are not rare. The study is done to assess the pattern of the component vessels of its anterior part with regard to Right- Left variations and compare with other studies. MATERIAL AND METHOD: 56 formalin fixed cadavers were analyzed. The diameter, length and variations of the following vessels were observed: Anterior Cerebral Artery (proximal A1 segment to distal A2 segment) and anterior communicating artery. Statistical analysis was done by Statistica 14.0.1 software. RESULT: 53.57% had normal anterior cerebral artery- anterior communicating artery complex. Length and diameter were slightly more on left side. Unilateral hypoplasia, Azygos and Tripple Anterior Cerebral Artery was present in 21.43%, 3.57 and 1.78% respectively. Aplastic, double and fenestration type anterior communicating artery were present in 5.3%, 8.92% and 1.78% respectively. CONCLUSION: Anatomical knowledge of variations should be updated regularly for neurosurgeons, radiologists and clinicians to avoid unexpected consequences.

The risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms: anatomical consideration and infarction territory.

PURPOSE: An anterior communicating artery is a common location for both ruptured and unruptured intracranial aneurysms, and microsurgery is sometimes necessary for their successful treatment. However, postoperative infarction should be considered during clipping due to the complex surrounding structures of anterior communicating artery aneurysms. This study aimed to evaluate the risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms and its clinical outcomes. METHODS: The data of patients who underwent microsurgical clipping of an unruptured anterior communicating artery aneurysm in our hospital between January 2008 and December 2020 were retrospectively analyzed. The patients' demographic data, anatomical features of the anterior communicating artery complex and aneurysm, surgical technique, characteristics of postoperative infarction, and its clinical course were evaluated. RESULTS: Notably, among 848 patients, 66 (7.8%) and 34 (4%) patients had radiologic and symptomatic infarctions, respectively. Univariate and multivariate logistic regression analyses showed that hypertension (odds ratio (OR), 1.99; [Formula: see text]), previous stroke (OR, 3.89; [Formula: see text]), posterior projection (OR, 5.58; [Formula: see text]), aneurysm size (OR, 1.17; optimal cut-off value, 6.14 mm; [Formula: see text]), and skull base-to-aneurysm distance (OR, 1.15; optimal cut-off value, 11.09 mm; [Formula: see text]) were associated with postoperative infarction. In the pterional approach, a closed A2 plane was an additional risk factor (OR, 1.88; [Formula: see text]). Infarction of the subcallosal and hypothalamic branches was significantly associated with symptomatic infarction ([Formula: see text]). CONCLUSION: Hypertension, previous stroke, posteriorly projecting aneurysms, aneurysm size, and highly positioned aneurysms are independent risk factors for postoperative infarction during surgical clipping of an unruptured anterior communicating artery aneurysm. Additionally, a closed A2 plane is an additional risk factor of postoperative infarction in patients undergoing clipping via the pterional approach.

Small symptomatic anterior communicating artery aneurysms: report of three cases and literature review.

PURPOSE: Given the anatomical relationship between the ACom complex and the optic nerve, small aneurysms of the ACom can present with visual symptoms. CASE REPORTS: We summarize and illustrate the clinical course of three patients with symptomatic small ACom aneurysms and collect similar other cases reported. RESULTS: Ten patients with small unruptured visually symptomatic anterior communicating artery aneurysms were found in the literature. Including three patients herein reported, the mean age at presentation was 56. The most common visual symptoms were bitemporal vision loss and/or a decrease in visual acuity. CONCLUSION: Unruptured aneurysms of the anterior communicating artery can present with visual symptoms due to compression of optic pathways, even at a small size. Prompt recognition and treatment of such a condition are paramount as new onset of visual symptoms can signify impending rupture akin to small PCom aneurysms compressing the third nerve. We discuss a few pitfalls of clipping small ACom aneurysms compressing the optic nerve.

Anterior communicating artery aneurysm in a young patient with Fahr's disease: case presentation.

BACKGROUND AND IMPORTANCE: Fahr disease is an uncommon disorder defined as prominent calcification in basal ganglia, dentate nuclei of cerebellum, pulvinar thalami and subcortical white matter and it has been shown that calcium is the major factor that causes the hyperdensity on computer tomography (CT). Spontaneous subarachnoid hemorrhage from an aneurysm in a patient with Fahr disease was first reported by Al-Jehani et al. in 2012 in a 54-year-old female patient with calcification of basal ganglia and deep cerebellar nuclei and a subarachnoid hemorrhage from a right posterior communicating artery aneurysm. CLINICAL PRESENTATION: We present a 17 years old patient with Fahr disease with an anterior communicating artery aneurysm rupture. CONCLUSION: There are few reports of intracranial hemorrhage with Fahr's disease. It may be suggested that excessive calcium accumulation contributes to aneurysm formation or rupture.

Unreported branching pattern of the triplicated anterior cerebral artery associated with multiple bilateral variants of the superior cerebellar artery detected by computed tomography angiography and 3D modeling.

A 26-year-old patient underwent a successful ablation of Grade 2 diffuse astrocytoma of the right parietal lobe. The postoperative computed tomography angiography with 3D modeling revealed a residual avascular porencephalic cyst. Otherwise, multiple arterial variants have been encountered. First, the left A1 segment was fenestrated, and three A2 segments arose from the anterior communicating artery. The middle A2 segment was dominant and supplied left callosomarginal and both pericallosal territories. The right A2 segment supplied the right callosomarginal territory, while the left A1 was limited to the left orbitofrontal and frontopolar territories. This configuration represents a triplicated anterior cerebral artery with an unusual branching pattern not included in the classification of Baptista. In addition, on both sides, superior cerebellar artery duplication was present, with one arising from the basilar artery and the other from the P1 segment of the ipsilateral posterior cerebral artery. The left lower superior cerebellar artery was early bifurcated. It is the first time such a cerebrovascular configuration has been reported. Because of the several clinical and surgical applications of the anterior cerebral artery and superior cerebellar artery variants, this case report is of utmost interest to anatomists, radiologists, and neurosurgeons.

Endovascular Treatment for Anterior Communicating Artery Aneurysms.

Previously, anterior communicating artery aneurysms were considered unsuitable for endovascular treatment. In recent years, however, endovascular treatment has been increasingly performed due to the fact that it is less likely to cause high dysfunction compared to surgery and the treatment has been improved. The International Subarachnoid Aneurysm Trial reported anterior communicating artery aneurysms comprise 45.4% of cerebral aneurysms on which both endovascular treatment and surgery are suitable. The use of the endovascular treatment for anterior communicating artery aneurysms is expected to increase in the future. In this paper, we present cases from our institution based on the characteristics of anterior and distal communicating artery aneurysms, treatment strategies, and treatment indications.

Intra-procedural complications, success rate, and need for retreatment of endovascular treatments in anterior communicating artery aneurysms: a systematic review and meta-analysis.

In recent years, intracranial aneurysms have been widely treated with endovascular methods. The anterior communicating artery (Acom) is the most common site of intracranial aneurysms. Despite its effectiveness, endovascular interventions can be associated with various intra-procedural and post-procedural complications. A systematic review of the literature was performed through PubMed, Embase, Scopus, and Web of Sciences databases up to March 18, 2022. The pooled rates of intra-procedural complications, mortality, procedure-related morbidities, the immediate and late aneurysm occlusion, and also the necessity for retreatment were calculated by applying random-effects models. A total of 41 articles with 4583 patients were included in the meta-analysis. The pooled rate of overall intra-procedural complications was 9.6% (95% CI: 7.7 to 11.8%). The initial rupture status and also type of EVT procedure did not affect the overall complication rate. The pooled rate of intra-procedural thrombosis, aneurysm rupture, coil prolapse, and early aneurysm rebleeding were 6.1% (95% CI: 4.5 to 8.2%); 4.2% (95% CI: 3.4 to 5.2%), 4.7% (95% CI: 3.2 to 6.7%), and 2.2% (95% CI: 1.5 to 3.2%), respectively. Our analysis showed that intra-procedural mortality occurred in 1.7% (95% CI: 1.1 to 2.5%) and procedure-related permanent morbidities in 3.3% (95% CI: 2.3 to 4.7%) of patients. Endovascular methods achieved complete and near to complete aneurysm occlusion (Raymond-Roy occlusion classification 1 and 2) in 89.2% (95% CI: 86.4 to 92.5%) of cases post-procedure, and 9.5% (95% CI: 7.3 to 12.4%) of patients needed retreatment due to recanalization in follow-ups. Endovascular treatment can serve as an acceptable method for Acom aneurysms. However, improved endovascular treatment equipment and new techniques provide more satisfactory outcomes for complicated cases.

Variations of perforating arteries of anterior communicating artery in cases with anterior communicating artery aneurysms: a cadaveric anatomical study.

PURPOSE: In terms of postoperative morbidity and mortality, preservation of the perforating arteries branching from the anterior communicating artery (ACoA) during clipping is particularly imperative in patients with ACoA aneurysm. In the present study, we aimed to investigate whether perforating arteries originated from ACoA were pushed away in a different location in patients with ACoA aneurysm. Furthermore, if they did so, we aimed to identify the direction in which they were dislocated and how the perforating arteries could be preserved during clipping. METHODS: Herein, we categorized 40 brains obtained from cadavers into two groups. The first (n = 26) and second (n = 14) groups included cases without and with ACoA aneurysms, respectively. After completing the preparation procedure, the brains were dissected using surgical microscope and the relevant anatomical region was examined and photographed. Finally, statistical analyses were performed on the data and the results were documented. RESULTS: In the aneurysms with posterior and superior projections, the perforators appeared to be pushed away inferiorly and were frequently noted at the anteroinferior part of the aneurysm neck. Most of the cases, where one of the A1s was larger at one side, the perforating arteries arose from the larger A1 side. CONCLUSION: The mortality and morbidity associated with damage to the perforators can be reduced by approaching the patient from the dominant A1 side and pursuing the perforators primarily at the anteroinferior part of the aneurysm neck in the aneurysms with superior and posterior projections.

A complex anterior communicating artery aneurysm projecting into the sella turcica.

Intrasellar aneurysms are rare vascular lesions that typically present with symptoms of mass effect upon the pituitary gland and optic apparatus. Most arise from the internal carotid artery, while only a handful of case reports describe intrasellar aneurysms originating from the anterior communicating artery. The appropriate recognition and management of these lesions are critical to prevent irreversible neurological deficits and catastrophic hemorrhage. Here, we highlight a patient with an anterior communicating artery aneurysm projecting into the sella turcica, leading to hyponatremia, pituitary dysfunction, and chiasmal compression.

Collateral flow at circle of Willis in healthy condition.

Experimental simulation of cerebrovascular system would be very beneficial tool to evaluate millions of human body cascade sequence. The Circle of Willis (CoW) recently named Cerebral Arterial Circle (CAC) is a main loop structure of cerebral circulatory system which positioned at the cranium base. In this research, we investigate cerebral artery flow pattern in cerebral arteries including afferent, Willisian, and efferent arteries of CAC emphasizing on communicating and connecting arteries which are main routes in CAC and as a risky sites when autoregulation is occurred in terminal parts of middle cerebral arteries (MCAs) by PMMA (Polymethyl methacrylate) chip and high quality camera which depict Sequential images. This novelty study analyze flow pattern in CAC that have been challenging subject area for many years which have investigated by scientists yet, because flow pattern in CAC indicate complication progression. This research tries to construct new platform in cerebral circulation analyzing method by reliable experimental in-vitro approach. The outcomes of this study demonstrate that communicating arteries especially anterior communicating artery (ACoA) is main artery in CAC flow distribution.

Embryology of the anterior communicating artery complex: implications on possible adult variants.

The anterior cerebral artery (ACA) and the anterior communicating artery (AComA) are important arteries of the telencephalon and are prominent location for cerebral aneurysms. Their embryological development is closely linked, and explains the possible variants seen in adults. In this paper, we present details related to the development of these two arteries, focusing on some variants such as the infra-optic course of the ACA, the unpaired ACA, and the persistent primitive olfactory artery.

Multiple cerebral arterial variations incidentally detected by magnetic resonance angiography: a case report.

We herein report a case of multiple variations, including (1) anterior communicating artery duplication, (2) accessory anterior cerebral artery (ACA), (3) distal origin right accessory middle cerebral artery (MCA) with bifurcation, (4) proximal origin left accessory MCA with bifurcation, (5) right superior cerebellar artery (SCA) duplication, and (6) left SCA early bifurcation. These variations were found incidentally by magnetic resonance (MR) angiography. Volume-rendering images of MR angiography were more useful than maximum-intensity-projection images for identifying these variations, especially bilateral accessory MCAs, which were superimposed with the A1 segment of the ACAs and the M1 segment of the MCAs.