BackgroundSubarachnoid hemorrhage (SAH) commonly causes cerebral vasospasm and delayed ischemia. Spasm of the posterior communicating artery (PCoA) can disrupt cerebral hemodynamics. We assessed its effect on cerebral pulsatility in a rabbit SAH model, focusing on intracranial pressure pulse amplitude as an early, sensitive marker of vasospasm-driven change, whereas global CBF or neurological outcomes generally require larger or longer studies.MethodsRabbits were randomly assigned to three groups: control (no injection), sham-controlled (saline injection), and SAH (0.75 mL autologous blood injection into the basal subarachnoid space near the PCoA under anesthesia). Heart rate and cerebral pulsation amplitude (measured via intracranial pressure transducer) were recorded on day 1 and day 7. On day 7, animals were euthanized, and histological analysis of the PCoA was performed. Vasospasm index (VSI) was calculated as the ratio of arterial wall area to lumen area. Group comparisons and temporal changes were assessed statistically.ResultsTwenty-three rabbits completed the study (five control, five sham-controlled, 13 SAH, two SAH animals excluded due to early mortality). On day 1, the SAH group showed a significantly reduced pulsation amplitude compared to controls and sham-controlled groups. By day 7, pulsation amplitude partially recovered in the SAH group but remained lower than in controls. Control and sham-controlled groups exhibited a slight, non-significant decline in pulsation. The VSI was highest in the SAH group, moderate in sham-controlled, and lowest in the control groups. Heart rate declined over time across all groups, with significant bradycardia in the SAH group by day 7.ConclusionPCoA vasospasm following experimental SAH results in a sustained reduction in cerebral pulsatility. These findings suggest that localized vasospasm disrupts pulsatile intracranial dynamics, potentially contributing to SAH-related pathophysiology.

This study aimed to identify predictive factors for incomplete occlusion in posterior communicating artery (PCoA) aneurysms after endovascular treatment (EVT) and investigate the role of fetal-type posterior cerebral artery (fPCA) in occlusion outcomes using quantitative digital subtraction angiography (QDSA). We analyzed 287 patients with 292 PCoA aneurysms treated with EVT between 2016 and 2022. Aneurysms were categorized into incomplete (n = 49) and complete (n = 243) occlusion groups based on follow-up DSA. Clinical, morphological, and hemodynamic parameters from QDSA were compared, and independent risk factors were identified via multivariate logistic regression. Predictive performance was evaluated using area under the curve (AUC) and subgroup analysis with Benjamini-Hochberg correction for fPCA effects. Independent risk factors for incomplete occlusion included size (p < 0.001, OR = 1.127), neck cerebral blood flow (CBF) (p = 0.001, OR = 4.024), simple coiling (p < 0.001, OR = 4.635), ruptured status (p = 0.002, OR = 3.281), and fPCA (p = 0.030, OR = 2.218). AUCs for the combined model, size, neck CBF, simple coiling, ruptured status, and fPCA were 0.822, 0.721, 0.708, 0.656, and 0.603, respectively. In the fPCA subgroup, ruptured status, neck CBF, neck cerebral blood volume (CBV), PCoA CBF, and PCoA CBV showed significance, while in the non-fPCA subgroup, only simple coiling and size remained significant. Size, neck CBF, simple coiling, ruptured status, and fPCA are independent risk factors for incomplete occlusion in PCoA aneurysms treated with EVT. fPCA likely influences incomplete occlusion through hemodynamic changes.

To describe a case of right posterior communicating artery (PCoA) arising from the extreme proximal internal carotid artery (ICA), paraclinoid segment, diagnosed by magnetic resonance angiography (MRA). An 80-year-old woman with subacute hemorrhagic infarction of the right basal ganglia underwent MRA using a 3-Tesla scanner. MRA was performed using a standard 3-dimensional time-of-flight technique. MRA of the intracranial region revealed no pathological lesions. A right fetal-type posterior cerebral artery (PCA) was observed. The hyperplastic right PCoA arose from the paraclinoid segment of the ICA, just distal to the origin of the ophthalmic artery, which is an extremely proximal point relative to the usual point at which it arises. The PCoA usually arises from the supraclinoid segment of the ICA, just proximal to the origin of the anterior choroidal artery. The PCA, which is mainly supplied by ICA, is called a fetal-type PCA, and there is a hyperplastic PCoA. Extremely rarely, the PCoA arises from a fenestration of the supraclinoid ICA. In such cases, the PCoA arises from the extremely proximal point of the ICA if the distal segment of the fenestration regresses. To our knowledge, no similar cases have been reported in the relevant English-language literature. Although the image quality of MRA is insufficient, careful observation of the source images and creation of volume-rendering MRA images are important for the correct diagnosis of this extremely rare variation.

The ageing global population is experiencing an increased prevalence of cerebrovascular diseases, such as stroke and dementia. This highlights a need for understanding the pathophysiological mechanisms of age-related cerebrovascular alterations, alongside benefits of interventions such as physical activity. Therefore, our aims were to: (1) examine the impact of ageing and exercise training on cerebrovascular function and (2) to characterize age- and exercise training-related changes in the hippocampus transcriptome. Young and old male rats were randomized to a sedentary condition or exercise training for 10weeks. In the first protocol, cerebral arteries were isolated to test vasomotor reactivity, quantify gene/protein expression and assess nitric oxide production. In the second protocol, anhedonia was assessed and hippocampal tissue collected for RNA-sequencing. Bioinformatic analyses (i.e. protein-protein interaction mapping) were performed. Ageing impaired endothelium-dependent vasoreactivity in the posterior communicating artery (PCoA), with a shift from endothelial nitric oxide synthase (NOS)- to neuronal NOS-mediated vasorelaxation, as well as alterations in oxidative stress production. In support, PCoA superoxide-mediated vasoreactivity and neuronal NOS-mediated production of NO decreased with age. Exercise enhanced vasodilatation in young rats, but the results suggested reduced cerebrovascular plasticity in older animals. In the second protocol, exercise training attenuated the age-related increase in anhedonia behaviour. Hippocampal RNA-sequencing revealed altered inflammatory and oxidative stress pathways with ageing that were mitigated by exercise training. Our findings underscore the complex interplay between vascular/neuronal factors in the ageing brain. Furthermore, these findings highlight the therapeutic potential of exercise in mitigating the adverse effects of ageing on cerebral health. KEY POINTS: Ageing is associated with increased risks of cerebrovascular disease and neurocognitive decline. Little is known about the underlying mechanisms involved in this process, limiting our ability to design appropriate interventions. Ageing is associated with alterations in cerebrovascular function, including possible changes in the mechanisms underlying vasomotor reactivity. Hippocampal RNA-seq revealed age-related alterations in neuronal, vascular, immune and oxidative-stress related signalling pathways. Exercise training may have mitigated many of these age-related changes, suggesting that enhancing physical activity may be a feasible means to preserve cerebral health in older individuals.

Anatomical variations of the circle of Willis (CoW) are closely associated with the occurrence of intracranial aneurysms (IAs). However, the impact of anatomical variations on the rupture risk of IAs remains unclear. The purpose of this study was to explore the effect of artery absence on the internal flow and rupture risk of IAs. A one-dimensional (1D) solver was combined with a 3-dimensional (3D) fluid-structure interaction (FSI) model to effectively quantify the hemodynamic characteristics inside IA under artery absence. The 1D results showed that the absence of anterior cerebral artery A1 segment (ACA-A1) or posterior cerebral artery P1 segment (PCA-P1) will trigger a compensatory blood flow effect, leading to significant blood flow variations of the anterior communicating artery (ACoA) and internal carotid artery (ICA). By FSI calculation, in the absence of ACA-A1, the maximum wall shear stress (WSS) within the ACoA aneurysm increased by 103% or more compared to the complete CoW due to blood inflow jet. In addition, WSS increased by 45% and 12% in the contralateral ICA and posterior communicating artery (PCoA) aneurysm respectively, whereas it decreased by 33% and 35% in the ipsilateral ICA and PCoA aneurysm, respectively. The absence of PCA-P1 had a less significant impact on the global blood flow of the CoW compared to the absence of ACA-A1, but it still led to an increase in WSS within the ipsilateral ICA and PCoA aneurysms (25% and 22%, respectively). The absence of ACA-A1 or PCA-P1 may serve as an IA rupture risk factor. If ACA-A1 or PCA-P1 absence is identified clinically alongside an aneurysm, proactive treatment strategies are advised.

Oculomotor nerve palsy (ONP) due to compression from posterior communicating artery (PCoA) aneurysms has been well described in the literature. Early treatment is advocated for reduction of rupture risk and improvement in ONP recovery. However, the actual natural history in patients with chronic symptoms is unclear. In this study, we present a case series of patients with greater than a week to several years of oculomotor palsy before definitive treatment. This is a case series derived from a prospective-accrued database of patients treated at our institution between 1991 and 2024 who presented with subacute to chronic (≥1 week) ONP from PCoA aneurysm. Baseline characteristics, aneurysm size, and follow-up outcomes were evaluated. A total of 17 patients were included in this series, of which 5 (29.4%) presented with aneurysm rupture. Most patients were female (94.1%) with a median age of 56 (IQR = 53-66) years. The duration of oculomotor palsy ranged from 1 week to 10 years. Eleven patients (64.7%) had microsurgical clipping, and 5 (29.4%) were treated endovascularly. Four patients (23.5%) had complete recovery of the ONP, all of whom with symptom duration of less than 5 weeks. Chronic oculomotor palsy from untreated PCoA aneurysm is uncommon. Although ONP may not portend imminent aneurysm rupture, early definitive management is still recommended for better chance of ONP functional recovery.

Inter-areal communication is crucial for brain function. Given the largely contralateral organization of the brain, bimanual coordination likely involves interactions across the two cerebral hemispheres for motor planning and execution. The parietal reach region (PRR) is an early node in the sensorimotor transformation stream. Here we examine the contributions of direct callosal connections between left and right PRR to bimanual coordination. Using manganese-enhanced magnetic resonance imaging, we traced callosal pathways crossing the midline and found that PRR-PRR connections are restricted to the splenium. We then temporarily blocked these fibers with lidocaine while measuring behavioral performance and interhemispheric coherence. Blockade reduced task-specific PRR-PRR coherence during bimanual movements. Behaviorally, blockade sped movement initiation across tasks, consistent with an inhibitory role of interhemispheric communication, reduced the temporal synchrony of bimanual movements to a common target and reduced errors for bimanual movements to separate targets. These findings provide causal evidence that posterior callosal communication supports spatial coordination of bimanual actions but may also constrain independent limb control.

While digital subtraction angiography (DSA) is traditionally used for moyamoya disease (MMD) assessment, its invasiveness and limitations necessitate alternative methods. The higher signal-to-noise ratio (SNR) and contrast-to-noise ratio of 7T MRI improve the clarity of the image and retains the details of the structures. We aimed to assess the performance of 7T MRI in identifying hemorrhagic risk features of MMD compared with 3T MRI and DSA. This cross-sectional study recruited patients with MMD who underwent both 7T and 3T MRI scans within a 24-hour window, from March 2022 to December 2023. Patients were categorized into hemorrhagic, ischemic, and asymptomatic groups based on standard MRI findings and clinical symptoms. Corresponding DSA images acquired within 90 days were also collected as a comparative benchmark. Hemorrhage risk factors including dilatation and branch extension of the anterior choroidal artery (AChA) and posterior communicating artery (PComA) were assessed and graded on time-of-flight magnetic resonance angiography (TOF-MRA) and DSA images following established protocols. The hemorrhage locations were classified into anterior and posterior circulation groups. A total of 180 patients (mean age, 43.95 ± 11.02 [SD] years; 53.9% female) were included in the study (hemorrhagic = 51, ischemic = 37, asymptomatic = 92). Notably, 42.4% of AChA and 27.7% of PComA anomalies detected on 7T TOF-MRA were absent on 3T imaging. The 7T TOF-MRA demonstrated a strong correlation with DSA in assessing the AChA stage (weighted κ = 0.891, p < 0.001) and PComA stage (weighted κ = 0.761, p < 0.001). Higher AChA (70.6% vs 21.6% vs 6.5%, p < 0.001) and PComA (51.0% vs 8.1% vs 12.0%, p < 0.001) grades were more common in patients with hemorrhagic MMD compared with ischemic and asymptomatic groups. In binary logistic regression analysis for hemorrhagic and ischemic groups, elevated stages of AChA (odds ratio [OR] 1.90, 95% CI 1.20-3.54, p = 0.042) and PComA (OR 3.89, 95% CI 1.76-8.58, p = 0.001) were associated with increased hemorrhagic risk. Furthermore, the proportion of higher AChA (62.2%, p = 0.008) and PComA (51.3%, p = 0.010) grades were more prevalent in cases involving both anterior and posterior circulations. The 7T TOF-MRA visualization of dilatation and branching extension of the AChA and PComA indicates a heightened risk of hemorrhage, suggesting that this imaging technique could serve as a valuable noninvasive tool for identifying hemorrhagic vulnerabilities in MMD. ClinicalTrials.gov, NCT05287750, Brain Diseases on 7.0T Magnetic Resonance Imaging, First Submitted January 2022. clinicaltrials.gov/study/NCT05287750. This study provides Class II evidence that 7T-TOF MRA accurately distinguishes hemorrhagic risk in patients with MMD compared with 3T-TOF MRA and DSA.

Background/Objectives: The fetal-type posterior cerebral artery (fetal PCA) is an anatomical variant that alters hemodynamics and may influence posterior communicating artery (PCoA) aneurysm rupture risk. Aneurysm shape and size irregularity are key rupture predictors. This study investigates the impact of fetal PCA on PCoA aneurysm morphology and rupture risk using a radiomics-based approach. Methods: We retrospectively analyzed 87 patients with PCoA aneurysms (39 ruptured, 48 unruptured) treated at a tertiary center (January 2017-December 2022). Seventeen morphological parameters and 18 radiomic features were extracted per aneurysm. Patients were grouped by fetal PCA presence. Logistic regression and receiver operating characteristic (ROC) analyses identified rupture predictors. Results: Of 87 aneurysms, 38 had fetal PCA (24 ruptured, 14 unruptured), and 49 did not (15 ruptured, 34 unruptured). Fetal PCA was significantly associated with rupture (odds ratio [OR]: 3.28, p = 0.018). A higher non-sphericity index (NSI) correlated with rupture risk (OR: 3.35, p = 0.016). In non-fetal PCA aneurysms, size-related parameters such as height (6.83 ± 3.54 vs. 4.88 ± 2.57 mm, p = 0.034) and area (190.84 ± 167.08 vs. 107.94 ± 103.10 mm2, p = 0.046) were key rupture predictors. In fetal PCA aneurysms, flow-related parameters like vessel angle (55.78 ± 31.39 vs. 38.51 ± 24.71, p = 0.035) were more influential. ROC analysis showed good discriminatory power, with an area under the curve: 0.726 for fetal PCA and 0.706 for NSI. Conclusions: Fetal PCA influences PCoA aneurysm rupture risk and morphology. NSI is a reliable rupture marker. Integrating morphological and anatomical data may improve rupture risk assessment and clinical decision-making.

Fetal-type posterior communicating artery (PComA) is considered when it serves as a dominant source of blood supply to the distal segment of the posterior cerebral artery (PCA) instead of being supplied as usual from the basilar arterial system. The infundibular origin of the PComA from the internal carotid artery (ICA) is a commonly observed anatomical variant, which has important implications for cerebrovascular dynamics. Infundibular dilatation may be complicated by a saccular aneurysm. Nevertheless, we present for the first time a case of infundibular origin of a right PComA of a fetal type, associated with a fusiform aneurysm of the terminal segment of the ICA. We hypothesize that the infundibular origin of PComA occurred due to the persistence of the fetal pattern of PComA and that it was a predisposing factor for the development of a fusiform aneurysm at the terminal segment of ICA. We recommend follow-up MRI for infundibula because of the high risk of their evolution into true aneurysms.

The Circle of Willis (CW), visualized via Magnetic Resonance Angiography (MRA), is crucial for assessing cerebral circulation. Accurate artery identification is essential not only for detecting stenosis and pathological changes but also for understanding vascular adaptations in healthy aging. Manual CW assessment is time-consuming, necessitating automated alternatives. This study evaluates intracranial artery diameter estimations from the Express IntraCranial Arteries Breakdown (eICAB) toolbox against manual measurements. eICAB was tested on 631 participants from the Northern Manhattan Study (NOMAS) with 1.5T MRA images (0.293 × 0.293 × 1 mm resolution). We analyzed eICAB’s detection and diameter estimation accuracy of the Internal Carotid (ICA), Basilar (BA), Anterior Cerebral (ACA), Middle Cerebral (MCA), Posterior Cerebral (PCA), and Posterior Communicating (PCom). eICAB showed over 95% accuracy in detecting major arteries except for PCA and PCom (∼80%). Diameter discrepancies were generally ≤0.5 mm, with ICA and BA reaching 1 mm. Spearman correlation (p ≪ 0.05) confirmed strong agreement between automated and manual measurements. Resampling at 0.2083 mm improved precision. eICAB accurately identifies CW arteries and estimates diameters, demonstrating strong clinical and research potential.

INTRODUCTION: Comparing microsurgery with endovascular treatment (EVT) regarding favorable oculomotor nerve palsy (ONP) recovery outcomes in cases associated with posterior communicating artery (PComA) aneurysms has been studied extensively. however there is no consensus on the treatment timing, nuances for different patients subgroups and ONP recovery time course. METHODS: A systematic review and meta-analysis were conducted by searching PubMed, Embase, Scopus, and Web of Science databases. The extracted data included patient demographics, details on treatment modalities and timing, and characteristics of PComA aneurysms ONP caused by unruptured or ruptured aneurysms. The primary outcome was ONP favorable recovery. We used random effect models to calculate odds ratios (OR) and pool prevalence with 95% confidence intervals (CI). RESULTS: 40 studies met the inclusion criteria. Microsurgery was associated with higher rates of favorable ONP recovery outcomes in the short term follow up. After 12 months, comparable recovery outcomes were identified [18 months: (0.87 vs 0.64, P-value = 0.36); =24 months: (0.86 vs 0.72 P-Value = 0.26)] and among patients = 60 years, = 7mm aneurysms, ruptured aneurysms, and partial ONP at presentation. Delayed treatment was associated with significantly lower rates of favorable recovery, regardless of the treatment (OR: 3.04, 95% CI:2.02–4.56, P&lt;0.01). Early window (=7 days) microsurgery or EVT were similarly associated with more favorable ONP recovery (OR= 1.65, 95% CI = 0.63 – 4.31, P= 0.31). CONCLUSIONS: Microsurgery demonstrates better recovery of ONP within the first 12 months when compared to EVT. Nevertheless, early treatment (= 7 days from presentation) and prolonged follow-up reveals comparable favorable ONP recovery outcomes between microsurgery and EVT. These results imply the necessity for tailoring treatment selection by assessing the risks and advantages on an individual basis, considering both short-term and long-term outcomes.

To describe a case of abnormal fusion between the long P1 segment of the posterior cerebral artery (PCA) and the long posterior communicating artery (PCoA) diagnosed by magnetic resonance angiography (MRA). An 83-year-old woman with left pulsatile tinnitus underwent cranial MRA using a 3-Tesla scanner. MRA was performed using a standard 3-dimensional time-of-flight technique. MRA showed no dural arteriovenous fistula; however, there was a stenotic lesion in the precavernous segment of the left internal carotid artery (ICA). This lesion was not considered to be the cause of her symptoms. In addition, the left PCA arose from the basilar artery and the left ICA. There was a small connecting artery between these two PCAs at their proximal segments. These two PCAs fused distally and formed a single PCA. Thus, there was a large arterial ring. Partial maximum intensity projection (MIP) images showed that the left anterior choroidal artery (AChA) appeared normal. Thus, we concluded that there was no hyperplastic AChA, and there was abnormal fusion between the long P1 segment of the PCA and the long PCoA. We diagnosed the first case of abnormal fusion between the long P1 segment of the PCA and the long PCoA. Careful observation using MRA is important for the detection of rare arterial variations. Partial MIP MRA images are useful for identifying tiny arteries, such as the AChA.

Endoscopy’s ability to provide close observation, deep magnification, and multi-angle views has proven to be an effective tool for minimally invasive craniotomy in neurosurgery. However, no large case series have been published on the use of fully endoscopic-assisted minimally invasive keyhole craniotomy for clipping intracranial aneurysms (IAs). To evaluate the value of fully endoscopic-assisted minimally invasive keyhole craniotomy in the treatment of anterior circulation aneurysms. A retrospective analysis was conducted on 20 patients who underwent fully endoscopic-assisted minimally keyhole invasive craniotomy for clipping of IAs. A total of 9 anterior communicating artery (ACoA) aneurysms were clipped using the supraorbital keyhole approach (SKA). Additionally, 10 middle cerebral artery aneurysms (MCA) and 2 posterior communicating artery (PCoA) aneurysms were clipped using the pterional keyhole approach (PKA). The clipping success rate was 100% in all patients. Apart from one patient who experienced transient third cranial nerve palsy, one who developed an intracranial infection, and one who had a brief seizure, no other patients experienced serious complications. Except for one patient who had residual muscle weakness due to a preoperative basal ganglia hemorrhage, all other patients had a modified Rankin Scale (mRS) score of ≤ 1. Fully endoscopic-assisted minimally invasive keyhole craniotomy has promising applications in the treatment of anterior circulation aneurysms in Hunt-Hess grade 0-II, especially for unruptured aneurysms. Future multi-center studies are needed to confirm its broader applicability.

To compare the impact of two flow diverter devices (Pipeline Embolization Device [PED] and Tubridge Embolization Device [TED]) on branch vessels patency in intracranial aneurysm treatment, with specific focus on branch vessel outcomes and clinical safety. A retrospective analysis of 320 patients with 430 aneurysms and 602 covered branches treated with PED or TED was conducted. Statistical analyses included descriptive statistics and group comparisons. Potential predictors of aneurysm and branch occlusion were identified through univariate analysis followed by multivariate logistic regression. Propensity score matching was adjusted for baseline discrepancies, and the comparative analysis examined stent efficacy on branch vessels patency and clinical outcomes. Stenosis or occlusion rates were 6.1% for the ophthalmic artery (OA), 31.6% for the posterior communicating artery (PComA), 0.9% for the anterior choroidal artery (AChA), 40.5% for the anterior cerebral artery (ACA), and 0% for the middle cerebral (MCA), lenticulostriate (LSA), posterior inferior cerebellar (PICA), and anterior inferior cerebellar arteries (AICA). Before propensity score matching, branch vessels patency rates did not significantly differ between the PED and TED groups. After matching, 109 pairs were identified. No significant differences in angiographic outcomes for distal and proximal branch vessels regarding occlusion or stenosis were observed between groups (P values > 0.999 and 0.332, respectively). Branch obliteration was mostly asymptomatic. PED and TED showed comparable safety profiles and branch vessel patency rates. These findings indicate that FD treatment may be clinically safe for selected ICA and VA cases requiring branch vessel coverage.

BackgroundPreterm birth (< 37 weeks’ gestation) alters cerebrovascular development due to the premature transition from a foetal to postnatal circulatory system, with potential implications for future cerebrovascular health. This study aims to explore potential differences in the Circle of Willis (CoW), a key arterial ring that perfuses the brain, of healthy adults born preterm.MethodsA total of 255 participants (108 preterm, 147 full-term) were included in the analysis. High-resolution three-dimensional Time-of-Flight Magnetic Resonance Angiography (3D TOF MRA) datasets were analysed, measuring vessel diameters and classifying segments into different groups of CoW anatomical variations. Statistical comparisons assessed the prevalence of each variant group between preterm and full-term populations, as well as the relationship between CoW variability, sex, and degree of prematurity.ResultsWe identified 164 participants with variant CoW configurations. Unilateral segment hypoplasia (30%) and unilateral segment absence (29%) were the most common variations, with over 50% related to the posterior communicating artery (PComA). However, the incidence of absent segments was lower in preterm adults, who were more likely to exhibit variants associated with complete CoW configurations compared to full-term adults (p = 0.025). Preterm males had a higher probability of a group 1 variant (circles with one or more hypoplastic segments only) than the full-term group (p = 0.024). In contrast, preterm females showed higher odds of a group 4a variant (circles with one or more accessory segments, without any absent segments) in comparison to their full-term counterparts (p = 0.020).ConclusionsPreterm birth is linked to a distinct vascular phenotype of CoW in adults born preterm, with a higher likelihood of a CoW configuration with hypoplastic segments but a lower likelihood of absent segments. Future work should focus on larger prospective studies and explore the implications of these findings for normal development and cerebrovascular disease. Furthermore, TOF MRA might be a useful adjunct in the neurovascular assessment of preterm-born individuals.

Purpose and backgroundThe trigeminal artery is a rare anatomical variant, representing an embryonic vestige of the anastomosis between the internal carotid artery and the posterior circulator system, that can be asymptomatic or could have vast clinical manifestations produced by insufficient flow or by vascular nervous conflicts. This study is an anatomical presentation of 3 trigeminal artery cases observed at Medimar Imagistic Services Constanta.MethodsThe 3 trigeminal artery cases were discovered on a 860 magnetic resonance angiographies (0.35% of cases), made on a GE HD/e 8ch 1.5 T.ResultsIn all 3 cases, the arteries were rising from the right internal carotid artery and one from the left internal carotid artery, in 2 cases the origin was on the superior surface, and in one case, on the anterolateral surface, in all 3 cases from C4 horizontal cavernous segment. The artery caliber was between 2.7 mm and 5.1 mm; the artery length was between 26 and 32 mm. Other associated vascular malformations were: partial or total basilar artery hypoplasia, in one case posterior communicant artery agenesis, contralateral vertebral artery hypoplasia, posterior cerebral artery hypoplasia (in 2 cases), and no anastomosis between the P1 segment of the posterior cerebral artery with the posterior communicating artery (one case).ConclusionsWhile the trigeminal artery is a rare anatomical variant, it’s still a very important vessel situated in the posterior cerebral fossa, which needs to be taken into account in the case of neurosurgical interventions.

Direct visualization of the aneurysmal neck and its related perforating arteries during microsurgical clipping of posterior communicating artery (PCoA) aneurysms with posterior projection or true PCoA aneurysms through the pterional approach may be difficult and complicated. From January 2022 to January 2023, the clinical and angiographic information regarding PCoA aneurysms were retrospectively collected. Among them, 10 consecutive patients with PCoA aneurysms treated with microsurgical clipping via the subtemporal approach in our single institution were included. Herein, we analyzed and summarized our experience and clinical outcomes to further evaluate the efficacy, safety and feasibility of this approach as well as the indications. All aneurysms were completely clipped via the subtemporal approach. With respect to procedure-related complications, postoperative oculomotor nerve palsy occurred in one patient (10%), contralateral cerebral infarction in one patient (10%), and intraoperative rupture of the aneurysm in three patients (30%). There were no cases of temporal lobe contusion or venous injury in this group. Overall, Good outcomes were obtained in 9 patients (90%), and poor functional outcome was observed in 1 patient (10%) at the last follow-up. The management of true PCoA aneurysms and PCoA aneurysms projecting posteriorly is more complicated and challenging, and treating these lesions entails considerable risks via the pterional approach. Considering the above problems, we attempted to treat these refractory PCoA aneurysms through the subtemporal approach. Our results suggested that microsurgical clipping of these aneurysms via the subtemporal approach can achieve good clinical outcomes with a high preservation rate of the related branches. Appropriate patient selection, fully grasp of indications, precise understanding of the anatomy and thorough preoperative planning are crucial for successful surgery. The subtemporal approach appears to be a relatively safe and effective procedure in the experienced hands, and may be an alternative method for patients with true PCoA aneurysms or projecting posteriorly PCoA aneurysms which cannot be easily clipped from the pterional approach. It can provide a better lateral view to visualize the neck of the aneurysm, PCoA and its perforating vessels, as well as the other structures.

Variants of the cerebral arterial circle, both common and rare, are frequently documented. The authors present a distinct case involving a 54-year-old male patient who underwent a computed tomography angiogram (CTA), which was analyzed using planar slices and 3-dimensional reconstruction. In this case, the left posterior cerebral artery (PCA) received the posterior communicating artery (PComA) 7mm distal to its origin from the basilar artery (BA). In addition, an accessory vessel originated 4.2mm distal from the PComA origin, branching from the left internal carotid artery (ICA). This vessel was identified as an accessory posterior cerebral artery (APCA), corresponding to a hyperplastic anterior choroidal artery (AChA). This case illustrates a rare variant in the posterior circulation of the brain, in which the territory of the PCA is supplied by both the internal carotid and vertebrobasilar systems.

Long-term outcomes of carotid endarterectomy with eversion technique in patients with an open circle of Willis: A multicenter registry study.