Branch Of Middle Cerebral Artery Research Articles

The Vecta 46 intermediate catheter for mechanical thrombectomy of distal medium vessel occlusions: A single-center experience.

With emerging evidence supporting the clinical efficacy and safety of mechanical thrombectomy (MT) for distal medium vessel occlusions (DMVOs), MT devices specifically designed to navigate through smaller caliber and more delicate tortuous distal cerebrovasculature are required. This study describes our single-center experience using the AXS Vecta 46 intermediate catheter for first-line thromboaspiration of DMVOs. We identified all patients who underwent MT using the Vecta 46 for first-line thromboaspiration for primary or secondary DMVOs. We collected baseline clinical data, angiographic and clinical outcomes, as well as procedural complications. The primary outcome in question was the rate of successful recanalization, which was defined as a modified Thrombolysis in Cerebral Infarction score of ≥2b. We identified 43 patients who underwent MT using the Vecta 46 catheter for thromboaspiration of 54 DMVOs. Intervened vessels included the M2 (23/54), M3 (19/54), and M4 (6/54) branches of the middle cerebral artery, A2 (1/54), A3 (1/54), and A4 (1/54) branches of the anterior cerebral artery, and P1 (1/54), P2 (1/54), and P4 (1/54) branches of the posterior cerebral artery. The median number of passes for primary DMVOs was 2 (IQR: 1-3) and 1 (IQR: 1-1.25) for secondary DMVOs. The rate of successful recanalization was 100% (18/18) for primary DMVOs and 80.6% (29/36) for secondary DMVOs. First-pass effect (FPE) was noted in 55.6% (30/54) of all primary and secondary DMVO cases. Improved short-term clinical outcomes were observed in both the primary (National Institute of Health Stroke Scale [NIHSS] shift: -5 [IQR: -14.25 to -0.25]) and secondary (NIHSS shift: -5 [IQR: -10 to -2]) DMVO groups. A total of six patients died during their hospitalization, though none were deemed procedural-related. Our study demonstrates the safety and efficacy of the Vecta 46 intermediate catheter for thromboaspiration of both primary and secondary DMVOs, achieving high rates of successful recanalization and FPE.

Morphology and variations of middle cerebral artery: systematic review and meta-analysis.

To review morphometry, morphology, branching patterns and anomalies of middle cerebral artery (MCA). The databases of PubMed, Google Scholar and Scopus were searched with different keywords. The review comprised of 45 studies. Meta-analysis was done for dimensions of MCA, shapes, patterns and MCA anomalies. Newcastle-Ottawa Scale was used for assessment of literature. Statistical analysis was done using R software using meta package. Thirteen research were combined to determine the proportion of MCA length and pooled proportion was 16.53 cm (15.33 to 17.72 cm); I2=98%; P-value<0.01. Nine studies were combined to determine proportion of MCA diameter and pooled proportion was 2.85 cm (2.52 to 3.17 cm); I2=100%; P-value<0.05. M1 segment mean length is more on left side as compared to right side. Mean length in males (16.57±1.40 cm) is more than females (15.9±1.32 cm). Mean diameter of M1 segment is similar on both sides. Mean diameter in males (3.20±0.09 cm) is higher than females (3.14±0.18 cm). Different branching patterns observed were single trunk, early bifurcation, bifurcation, trifurcation, quadrifurcation and multiple trunks. The most typical MCA branching pattern is bifurcation. The shapes of MCA like straight shaped, U shaped, C shaped, inverted U shaped and S-shaped of M1 segment have been described. Straight MCA is the most common shape. The MCA measurements and branching pattern will assist surgeons in limiting errors in the treatment of cerebral aneurysms and infarcts and providing the best possible result for the patients. An understanding of MCA shape will aid surgeons and physicians in effective endovascular recanalization.

Intracranial bypass for giant aneurysms treatment assessed by computational fluid dynamics (CFD) analysis

Unruptured giant intracranial aneurysms (GIA) are those with diameters of 25 mm or greater. As aneurysm size is correlated with rupture risk, GIA natural history is poor. Parent artery occlusion or trapping plus bypass revascularization should be considered to encourage intra-aneurysmal thrombosis when other treatment options are contraindicated. The mechanistic background of these methods is poorly studied. Thus, we assessed the potential of computational fluid dynamics (CFD) and fluid–structure interaction (FSI) analyses for clinical use in the preoperative stage. A CFD investigation in three patient-specific flexible models of whole arterial brain circulation was performed. A C6 ICA segment GIA model was created based on CT angiography. Two models were then constructed that simulated a virtual bypass in combination with proximal GIA occlusion, but with differing middle cerebral artery (MCA) recipient vessels for the anastomosis. FSI and CFD investigations were performed in three models to assess changes in flow pattern and haemodynamic parameters alternations (wall shear stress (WSS), oscillatory shear index (OSI), maximal time averaged WSS (TAWSS), and pressure). General flow splitting across the entire domain was affected by virtual bypass procedures, and any deficiency was partially compensated by a specific configuration of the circle of Willis. Following the implementation of bypass procedures, a reduction in haemodynamic parameters was observed within the aneurysm in both cases under analysis. In the case of the temporal MCA branch bypass, the decreases in the studied parameters were slightly greater than in the frontal MCA branch bypass. The reduction in the magnitude of the chosen area-averaged parameters (averaged over the aneurysm wall surface) was as follows: WSS 35.7%, OSI 19.0%, TAWSS 94.7%, and pressure 24.2%. FSI CFD investigation based on patient-specific anatomy models with subsequent stimulation of virtual proximal aneurysm occlusion in conjunction with bypass showed that this method creates a pro-thrombotic favourable environment whilst reducing intra-aneurysmal pressure leading to shrinking. MCA branch recipient selection for optimum haemodynamic conditions should be evaluated individually in the preoperative stage.

Involvement of Subinsular Territory Stroke as Predictor of Outcome after Successful Endovascular Recanalization of Left Middle Cerebral Artery Occlusion.

Subinsular stroke (subIS) can occur between the penetrating middle cerebral artery (MCA) branches, which clinical and radiological findings sometimes encounter in patients after the recanalization of left proximal MCA occlusion. However, no supportive data are available to clarify this relationship. This study investigated whether the involvement of subIS can impact outcomes after successful reperfusion therapy. Data from 152 consecutive patients who underwent endovascular thrombectomy between 2019 and 2023 were collected. A 3-month functional independence defined as a modified Rankin Scale 0-2 (primary outcome) and influencing factors were analyzed retrospectively. Recanalization was achieved in 35 patients, of whom 11 (31%) developed subIS. Patients with subIS were older in age (81 vs. 75; p < 0.05), had lower apparent diffusion coefficient (ADC) values on admission (0.52 vs. 0.62; p < 0.001), and higher modified Rankin Scale (mRS) scores (4 vs. 2; p < 0.001) than those without subIS. In a multivariate analysis, subIS was independently associated with a worse functional outcome (odds ratio: 10.5, p = 0.02). The cut-off value of the ADCs was 0.52 with a sensitivity and specificity of 70% and 64%, respectively. Subinsular ischemic lesions contribute to poor functional independence in patients after the successful recanalization of left MCA occlusion. The attenuation of the ADC value in these territories could be a valuable predictor of the outcome.

Morphological characteristics of the cerebral cortex of a mini-pig under conditions of gene therapy after experimental stroke

Aim. To study the effectiveness of preventive gene therapy (within 2 days) and gene therapy in the acute phase (after 4 hours) of ischemic stroke in mini-pigs using an autologous leucoconcentrate (AutoLeuc) enriched with recombinant genes of vascular endothelial growth factor (VEGF165), glial cell line-derived neurotrophic factor (GDNF) and neural cell adhesion molecule 1 (NCAM1), as well as the migration of leukocytes transduced with a chimeric adenoviral vector serotype 5 with fiber 35 serotype (Ad5/F35) and the green fluorescent protein (GFP) genome into immune defense organs.Materials and methods. The experiment was conducted on 8-month-old Vietnamese lop-bellied mini-pigs (n=16). An ischemic stroke was created by occlusion of the distal branches of the left middle cerebral artery and the right common carotid artery. Genetically modified AutoLeuc was administered preventively intravenously 2 days before or in the acute phase 4 hours after stroke modelling; the control group was injected with 30 ml of saline solution. The morphology of the cerebral cortex was assessed using histological methods in the areas bordering the infarction and peri-infarction after 21 days. The migration of genetically modified Ad5/F35-GFP leukocytes into the brain, spleen, and submandibular lymph nodes was studied a week after stroke modelling.Results. In the peri-infarction zone, the content of pyknotic neurons in control animals was higher, while the number of capillaries was lower than in the gene therapy groups. In the latter, neurons had a typical morphology with preserved outgrowths; in the control group, the outgrowths were tortuous and fragmented. Fluorescence microscopy after injection of AutoLeuc with Ad5/F35-GFP revealed GFP-positive cells in the spleen and submandibular lymph nodes.Conclusion. 21 days after modeling a stroke in mini-pigs against the background of preventive gene therapy or gene therapy in the acute phase using VEGF165/GDNF/NCAM1 AutoLeuc, greater preservation of neurons and a higher density of capillaries in the peri-infarction zone of ischemic brain damage were established. Leukocytes with Ad5/ F35-GFP were found in the spleen and submandibular lymph nodes.

Newly formed and ruptured infectious intracranial aneurysm in few days following first intracranial aneurysm embolization concurrent with middle cerebral artery occlusion: A regrettable case in a baby child

AbstractInfectious intracranial aneurysm (IIA) and embolic cerebral infarction are well‐known devastating complications of children suffering infective endocarditis. In this report, we describe a successfully embolized IIA concurrent with bilateral middle cerebral artery (MCA) occlusion. Unfortunately, a newly formed IIA located in the contralateral MCA bifurcation ruptured at the seventh day following embolization. A 6‐month‐old female child was admitted to hospital 3 days following acute right limb mobility disorder. An interventional surgery history of congenital heart disease was confirmed. She was immediately started on antibiotic therapy and the computed tomography agiography (CTA) scan showed occlusion of the upper branch of the left MCA. Unfortunately an IIA was located in the distal artery region (DAR) of the ipsilateral anterior cerebral artery. Angiography (digital subtraction angiography) was performed and the DAR IIA was embolized by OnyX‐18 with Magic 1.2 Fr. microcatheter. On the sixth day, magnetic resonance imaging during the hospital stay showed reduced infarction area with no other special sign. Desperately, a major seizure with opisthotonos attacked the baby on the seventh day after embolization. An immediate CTA scan showed massive hematoma in the right basal ganglia and a ruptured bifurcate aneurysm of the right MCA. The parents refused positive treatment and discharged in considering the critical situation. It should be noted that IIA can be fast formed anywhere in cerebral artery and dynamic angio‐image should be performed as supervision.

Super-selective injection of propofol into the intracranial arteries enables Patient's self-evaluation of expected neurological deficit

IntroductionIt is hard to realize the extent of the expected postoperative neurological deficit for patients themselves. The provision of appropriate information can contribute not only to examining surgical indications but also to filling the gap between patient and expert expectations. We hypothesized that propofol infusion into the intracranial arteries (ssWada) could induce focal neurological symptoms with preserved wakefulness, enabling the patients to evaluate the postsurgical risk subjectively. MethodsPresurgical evaluation using ssWada was performed in 28 patients with drug-resistant epilepsy. Based on anatomical knowledge, propofol was super-selectively infused into the intracranial arteries including the M1, M2, and M3 segments of the middle cerebral artery (MCA), A2 segment of the anterior cerebral artery, and P2 segment of the posterior cerebral artery to evaluate the neurological and cognitive symptoms. We retrospectively analyzed a total of 107 infusion trials, including their target vessels, and elicited symptoms of motor weakness, sensory disturbance, language, unilateral hemispatial neglect (UHN), and hemianopsia. We evaluated preserved wakefulness which enabled subjective evaluations of the symptoms and comparison of the subjective experience to the objective findings, besides adverse effects during the procedure. ResultsPreserved wakefulness was found in 97.2% of all trials. Changes in neurological symptoms were positively evaluated for motor weakness in 51.4%, sensory disturbance in 5.6%, language in 48.6%, UHN in 22.4%, and hemianopsia in 32.7%. Six trials elicited seizures. Multivariate analysis showed significant correlations between symptom and infusion site of language and left side, language and MCA branches, motor weakness and A2 or M2 superior division, and hemianopsia and P2. Transient adverse effect was observed in 8 cases with 12 infusion trials (11.2 %). ConclusionThe ssWada could elicit focal neurological symptoms with preserved wakefulness. The methodology enables specific evaluation of risk for cortical resection and subjective evaluation of the expected outcome by the patients.

In silico analysis of embolism in cerebral arteries using fluid-structure interaction method

Ischemic stroke, particularly embolic stroke, stands as a significant global contributor to mortality and long-term disabilities. This paper presents a comprehensive simulation of emboli motion through the middle cerebral artery (MCA), a prevalent site for embolic stroke. Our patient-specific computational model integrates major branches of the middle cerebral artery reconstructed from magnetic resonance angiography images, pulsatile flow dynamics, and emboli of varying geometries, sizes, and material properties. The fluid-structure interactions method is employed to simulate deformable emboli motion through the middle cerebral artery, allowing observation of hemodynamic changes in artery branches upon embolus entry. We investigated the impact of embolus presence on shear stress magnitude on artery walls, analyzed the effects of embolus material properties and geometries on embolus trajectory and motion dynamics within the middle cerebral artery. Additionally, we evaluated the non-Newtonian behavior of blood, comparing it with Newtonian blood behavior. Our findings highlight that embolus geometry significantly influences trajectory, motion patterns, and hemodynamics within middle cerebral artery branches. Emboli with visco-hyperelastic material properties experienced higher stresses upon collision with artery walls compared to those with hyperelastic properties. Furthermore, considering blood as a non-Newtonian fluid had notable effects on emboli stresses and trajectories within the artery, particularly during collisions. Notably, the maximum von Mises stress experienced in our study was 21.83 kPa, suggesting a very low probability of emboli breaking during movement, impact, and after coming to a stop. However, in certain situations, the magnitude of shear stress on them exceeded 1 kPa, increasing the likelihood of cracking and disintegration. These results serve as an initial step in anticipating critical clinical conditions arising from arterial embolism in the middle cerebral artery. They provide insights into the biomechanical parameters influencing embolism, contributing to improved clinical decision-making for stroke management.

Mối liên quan giữa lâm sàng và hình ảnh học của nhồi máu não tái phát do tổn thương động mạch não giữa

Objectives: Evaluate the relationship between clinical and imaging of recurrent cerebral infarction dued to MCA damaged. Subjects and method: A cross-sectional, descriptive study of 77 patients with recurrent cerebral infarction dued to damaged middle cerebral artery treated at the Neurological Center, Bach Mai Hospital from July 2021 to August 2022. Results: Motor paralysis of the hemibody on the opposite side of the injury, paralysis of the central VII nerve on the opposite side of the injury and decreased sensation of the hemibody on the opposite side of the injury are symptoms seen at a high rate, accounting for 100% respectively; 90.9% and 77.9%. The proportion of patients with consciousness disorders from the beginning accounted for 49.4% of patients, 2 patients were in a deep coma when hospitalized (accounting for 2.6%). Language disorders including Broca’s language disorder, Wernicke’s language disorder and mixed language disorder accounted for 20/77 patients (26.0%). Horizontal eye and head deviation, circular muscle disorders, loss of attention on one side of the body, and hemianopia account for 32.5% respectively; 26.0%; 22.1%; 26.0%. 7.8% of patients had mental disorders and 14.3% of patients had seizures when hospitalized; The symptoms of headache, nausea, and vomiting accounted for 45.5% and 31.2%, respectively. Patients with symptoms clustered into Gerstman syndrome and Anton - Babinski syndrome account for a low rate: 9.1% and 11.7%. The most damaged arterial branch is the M1 branch with 31 patients, accounting for 40.2%; Oblique branches of the middle cerebral artery or putamen-striatum branches account for 32.5%. Only 4 patients had damage to branches M3 - M4 (accounting for 5.2%). The number of patients with damage to the M1 branch who had consciousness disorders accounted for the highest rate of 33.8%, with no patients with damage to the deep branch having consciousness disorders. Symptoms at hospital admission: consciousness disorders, speech disorders, turning eyes and head to the damaged hemisphere have a statistically significant relationship with the location of the damaged middle cerebral artery branch (p &lt; 0.05)Conclusion: Recurrent cerebral infarction due to damage to the middle cerebral artery has diverse clinical symptoms, depending on the damaged middle cerebral artery branch.

Realtime assessment of vascular occlusion and reperfusion in animal models of intraoperative imaging- a pilot study.

Intraoperative monitoring of blood flow (BF) remains vital to guiding surgical decisions. Here, we report the use of SurgeON™ Blood Flow Monitor (BFM), a prototype system that attaches to surgical microscopes and implements laser speckle contrast imaging (LSCI) to noninvasively obtain and present vascular BF information in real-time within the microscope's eyepiece. The ability of SurgeON BFM to monitor BF status during reversible vascular occlusion procedures was investigated in two large animal models: occlusion of saphenous veins in six NZW rabbit hindlimbs and clipping of middle cerebral artery (MCA) branches in four Dorset sheep brain hemispheres. SurgeON BFM acquired, presented, and stored LSCI-based blood flow velocity index (BFVi) data and performed indocyanine green video angiography (ICG-VA) for corroboration. Stored BFVi data were analyzed for each phase: pre-occlusion (baseline), with the vessel occluded (occlusion), and after reversal of occlusion (re-perfusion). In saphenous veins, BFVi relative to baseline reduced to 5.2±3.7 % during occlusion and returned to 102.9±14.9 % during re-perfusion. Unlike ICG-VA, SurgeON BFM was able to monitor reduced BFVi and characterize re-perfusion robustly during five serial occlusion procedures conducted 2-5 min apart on the same vessel. Across four sheep MCA vessels, BFVi reduced to 18.6±7.7 % and returned to 120.1±27.8 % of baseline during occlusion and re-perfusion phases, respectively. SurgeON BFM can noninvasively monitor vascular occlusion status and provide intuitive visualization of BF information in real-time to an operating surgeon. This technology may find application in vascular, plastic, and neurovascular surgery.

Anatomical variations of artery of angular gyrus

Context: Angular gyrus is an anatomical structure of the brain located in the parietal lobe, taking part in writing and reading, language-use, memory and attention and spatial recognition. It is supplied by the angular gyrus artery, which is one of the caudal branches of the middle cerebral artery. One of the clinical pathologies of the angular gyrus artery is the ischemic stroke of the angular gyrus in the dominant hemisphere, responsible for the presence of Gerstmann Syndrome: left-right disorientation, agraphia, alexia, acalculia and finger agnosia. This systematic review aims to present the variety of anomalies of the main cerebral artery and the angular gyrus artery.&#x0D; Objective: Preparing a systematic review of papers describing the course anomalies of the angular gyrus artery.&#x0D; Materials and methods: PubMed and Google Scholar electronic databases was searched for phrases: ‘Angular gyrus artery’, ‘Artery of angular gyrus’, ‘Middle cerebral artery branches’, ‘Branches of middle cerebral artery’, ‘Gerstmann Syndrome’ published between years 2015 and 2023. Also 3 papers published before 2000 were used. From the selected 30 papers, 6 were used to prepare this analysis.&#x0D; Results: The middle cerebral artery, from which arises the angular gyrus artery, is marked by a significant variety of its division, mainly the number of the dividing trunks of the artery. Depending on the type of the division, the angular gyrus artery can arise from the upper, middle or lower trunk and vary in sizes. It can also appear as a singular or two separate branches. Instances of the anomaly of both the angular gyrus artery and posterior parietal artery are rare, but reported.&#x0D; Conclusions: The angular gyrus artery is characterised by a number of anomalies in its course, separation from the middle cerebral artery, diameter and branching.

Competitive leptomeningeal flow impact on thrombectomy reperfusion grade rating

BackgroundCompetitive leptomeningeal flow (CLF) can be observed immediately after mechanical thrombectomy (MT) reperfusion with retrograde contrast clearing of the distal leptomeningeal branches from non-contrast opacified flow through different vascular territories....

Abstract WP141: Leptomeningeal Competitive Flow Impact on Thrombectomy Reperfusion Grade Rating

Background: The extent of reperfusion following thrombectomy (MT) for large vessel occlusion strokes is predictive of outcomes. There is still inter-rater variability in the reperfusion scoring. We noticed that some patients present with retrograde contrast clearing of the distal branches from non-contrast-opacified flow originated from different territories. We aim to evaluate the frequency of this phenomenon (“competitive flow” (CF)), to evaluate if it has an association with the degree of leptomeningeal collaterals, and its impact on eTICI score. Methods: This is a retrospective-analysis of our MT database spanning 11/2020-12/2021. We included consecutive cases of intracranial internal carotid (i-ICA) and middle cerebral artery (MCA) M1 occlusions. CF was defined by the observation of retrograde clearing of distal MCA branches that were previously opacified by antegrade reperfusion. The clearance of the distal branches is presumed to occur due to CF via non-contrast-opacified PCA or ACA flow. The washout was considered CF if it cleared abruptly with or without forward reconstitution of antegrade opacification. Results: We included a 125 patients. Median age was 64years, 51%were males. Baseline median NIHSS was 17 and ASPECTS 9. Median last-known-well-time to puncture was 7 hours, 30.4% received tPA. Final eTICI2c-3 was achieved in 81.6%. CF was present in 32(25.6%)patients. Baseline characteristics were similar between both groups. The CF arm had better leptomeningeal single-phase-CTA-collaterals(p=0.01) and smaller CTP malignant hypoperfusion volume(p=0.06) VS non-CF. The inter-rater-agreement for eTICI score was moderate when CF was present and excellent in its absence (Krippendorf’s alpha=0.65 and 0.81,respectively). There was poor agreement (K-value=0.3) for the presence versus absence of CF between both operators. Reviewer 1 (2-year-post-training) had correctly identified 46% of patients with consensus CF vs 90% to Reviewer 2 (9-year-post-training) after the consensus read. Conclusion: CF was observed in 32% of patients. CF was found to be associated with better collateral flow, and to impact the reported procedural eTICI rating.

Induction of Acute Ischemic Stroke in Mice Using the Distal Middle Artery Occlusion Technique.

Ischemic stroke remains the predominant cause of mortality and functional impairment among the adult populations globally. Only a minority of ischemic stroke patients are eligible to receive intravascular thrombolysis or mechanical thrombectomy therapy within the optimal time window. Among those stroke survivors, around two-thirds suffer neurological dysfunctions over an extended period. Establishing a stable and repeatable experimental ischemic stroke model is extremely significant for further investigating the pathophysiological mechanisms and developing effective therapeutic strategies for ischemic stroke. The middle cerebral artery (MCA) represents the predominant location of ischemic stroke in humans, with the MCA occlusion serving as the frequently employed model of focal cerebral ischemia. In this protocol, we describe the methodology of establishing the distal MCA occlusion (dMCAO) model through transcranial electrocoagulation in C57BL/6 mice. Since the occlusion site is located at the cortical branch of MCA, this model generates a moderate infarcted lesion restricted to the cortex. Neurological behavioral and histopathological characterization have demonstrated visible motor dysfunction, neuron degeneration, and pronounced activation of microglia and astrocytes in this model. Thus, this dMCAO mouse model provides a valuable tool for investigating the ischemiastroke and worth of popularization.

Challenging Cortical Explorations in Difficult-to-Localize Seizures: The Rationale and Usefulness of Perisylvian Paralimbic Explorations With Orthogonal Stereoelectroencephalography Depth Electrodes.

Stereoelectroencephalography (SEEG) is an invasive monitoring method designed to define and localize the epileptogenic zone (EZ) and explore the putative network responsible for the electroclinical seizures using anatomo-functional-electroclinical correlations. When indicated by semiology in selected patients, exploration of both limbic and paralimbic (PL) regions is indispensable. However, the PL cortex is located in deep and highly vascularized areas in proximity to the anterior Sylvian fissure and middle cerebral artery branches. Thus, those explorations are considered surgically challenging because of the multilobar location and fear of hemorrhagic events. Here, we discuss and illustrate the rationale and SEEG methodology approach in usefulness of exploring the PL regions using standard orthogonal SEEG depth electrode trajectories with the Talariach reference system. We retrospectively studied PL exploration from a cohort of 71 consecutive SEEG procedures from Nov 2019 to Nov 2022 and identified 31 patients who underwent PL trajectories. In 31 patients, there were 32 SEEG trajectories, and no major complications were observed. PL electrodes were consistently implanted in the C10/D10 coordinates of the Talariach reference coordinates. The most common confirmed EZ in our cohort was mesio-temporal (45%), followed by temporo-perisylvian regions (16%), ventromedial frontal (13%), and mesio-lateral temporal regions (13%). The PL contacts were involved in the EZ in 10 patients (32%). Of 31 patients, 25 underwent resective surgery, and 19 obtained Engel 1 outcome with a mean follow-up of 25 months (range 12-41 months) after surgery. The orthogonal perisylvian PL trajectories are feasible and useful in sampling multiple PL regions with single-electrode trajectories. In patients with perisylvian seizures, sampling PL structures may contribute to an improved understanding of seizure propagation and the optimal anatomic demarcation of the EZs in this surgically challenging region.

Late Removal of Brain-Penetrating Nails Adherent to Intracranial Arteries: A Case Report

BACKGROUND AND IMPORTANCE: Pneumatic nail guns are a rare cause of penetrating brain injury, and subsequent nail removal in the acute setting is well reported. However, reports of late removal or removal of nails adjacent to intracranial vessels are rare. In the delayed setting, scar formation around the nails and surrounding brain structures may complicate surgical removal. Here, we report a case of late removal of brain-penetrating nails adherent to the middle cerebral artery branches. CLINICAL PRESENTATION: A 70-year-old left-handed male presented with mild aphasia, vertigo, and facial nerve palsy. Imaging studies demonstrated two nails fired 2 months before in the right temporal lobe adjacent to the middle cerebral artery branches. The nails were surgically removed through a modified pterional approach after meticulous dissection of scar tissue adherent to the nails. Before removal, proximal vessel control was achieved. CONCLUSION: Brain-penetrating nail removal weeks after the original incident may be complicated by extensive scarring. This can be dealt with a generous craniotomy, proximal vessel control through microsurgical or endovascular means, and careful dissection of scar tissue around the nails.

Abstract 216: Endovascular Thrombectomy +/‐ Thrombolytics In Patients With Cocaine‐Related Acute Ischemic Stroke

Introduction The safety of thrombolytic therapy in patients with cocaine‐related acute ischemic strokes (AIS) has been investigated, but the safety of endovascular thrombectomy in cocaine‐related AIS remains unknown (1‐2). Here, we report preliminary descriptive data on endovascular thrombectomy with or without thrombolytics performed in cocaine‐related ischemic strokes at our institution. Methods A retrospective chart review was performed at our comprehensive stroke center from June 2020 to May 2022 to identify AIS patients with cocaine‐positive urine toxicology screens on admission. Baseline demographics, urine toxicology, National Institute of Health Stroke Scale (NIHSS) scores, neuroimaging, Trial of ORG 10127 in Acute Stroke Treatment (TOAST) criteria, location of stroke, home medications, comorbidities, medical management, and outcomes including modified Rankin Score (mRS) were reported. Results A total of 74 AIS patients were identified to be cocaine‐positive. Of these patients, 14 underwent endovascular thrombectomy (EVT). Only 3 of these 14 patients received intravenous thrombolytics. Including the EVT group, 8 out of 74 AIS patients received thrombolytics. The mean age was found to be 61 years with 86% being male. The most common locations of large vessel occlusion were the M2 branch of the right middle cerebral artery (MCA) (40%), the M2 branch of the left MCA (33%), the M1 branch of the right MCA (13%), left internal carotid artery (7%), and A1 branch of the anterior cerebral artery (7%). Based on TOAST criteria, 64% of strokes were large artery atherosclerosis, 29% cardioembolic, and 7% cryptogenic stroke. The mean initial NIHSS was 14. Average mRS on admission was found to be &lt; 1 and follow‐up mRS at 3 months was found to be 3. Conclusion Our data suggest that cocaine patients who underwent EVT on average had unfavorable functional outcomes defined as mRS &gt; 2, on follow‐up mRS at 3 months. This study highlights the importance of future larger studies to investigate endovascular thrombectomy +/‐ thrombolytics in cocaine‐related AIS.

Abstract 127: Delayed Thrombectomy In A Patient With Recurrent MCA Strokes

Introduction Prior research has demonstrated mechanical thrombectomy (MT) to be a safe and effective treatment for stroke patients with a large vessel occlusion (LVO).1 However, MT has generally only been studied in a time window of less than 24 hours.2 To the best of the authors' knowledge, this case report is the first publication of a MT done months after the initial stroke event, in a patient with recurrent strokes and an evolving occlusion visualized in the middle cerebral artery (MCA). Methods The patient is a 55‐year‐old man with a past medical history of a left‐sided MCA stroke 2 months prior to current admission with multiple transient ischemic attacks (TIAs) on dual antiplatelet therapy (DAPT), with no persistent residual deficits. His first stroke was preceded by about 1 week of intermittent confusion and right arm tingling. MRI at the time showed an acute embolic infarct in left MCA territory, and a CTA showed a sub‐occlusive thrombus vs. atherosclerotic plaque in the superior branch of the left MCA. He was discharged on DAPT, but his prior symptoms began to recur on a weekly basis, lasting for a few minutes each time. The patient eventually presented on this admission to the ED with persistent dysarthria and word finding difficulties. Within 4 hours, his exam improved to an NIHSS of 0. An MRI without contrast showed a new acute punctate infarct in the posterior left lateral temporal cortex. CT angiogram showed a persistent left M2 occlusion which was confirmed by the diagnostic cerebral angiogram. CT Perfusion also showed a large penumbra in the same region. The decision was made to perform MT, and complete recanalization was achieved. On 2‐month follow‐up, the patient continues to report no new symptoms since the time of MT. Results The patient’s positive outcome thus far at 60 day follow up indicates that MT can prove safe and efficacious even in significantly delayed time windows. This also shows that the decision to proceed with MT ought not to depend on time interval and degree of collaterals alone, but also on the pattern of symptoms the patient is exhibiting. The recurrent TIAs and strokes our patient was having indicates that, although collaterals had formed in response to his sub‐occlusive thrombus in the MCA, they were still unable to provide full compensation for this lost blood flow, leading to the patient’s intermittent symptoms. Conclusion This report demonstrates that MT can be safely and effectively utilized even in significantly delayed time windows in patients with recurrent TIAs or strokes.

Abstract 002: Examining Pulling Force Using Combined Stentreiver and Aspiration Technique in a Medium Vessel Thrombectomy Model

Introduction With the advent of smaller stent retrievers (SR) and aspiration catheters (AC) capable of accessing more distal locations, distal and medium vessel occlusions (DMVO) are emerging as promising targets for endovascular thrombectomy (EVT). However, considering the vulnerability of distal vessels to injury, it is imperative to understand the safety of various frontline techniques in these challenging scenarios. Using a vascular flow model, we sought to investigate the optimal size, strategy, and positioning of a stent retriever and aspiration catheter to minimize the pulling force exerted on the M2 vasculature. Methods We used a silicone vascular flow model with moderate tortuosity that replicated the left‐sided anterior circulation, including middle cerebral artery (MCA) branches in the M2 territory. An 8 French Cook Shuttle guide sheath was inserted coaxially with a Catalyst 7‐132 cm aspiration catheter and TrevoTrak 21 microcatheter. To measure pulling force, an Imada force gauge DST‐1A was placed at the M2 and a DST‐11A at the proximal end of the microcatheter. The Solitaire 4x20 mm Solitaire stent‐retriever was pulled at 4 mm/sec with the AC in the proximal cavernous carotid segment (NoAsp), proximal M1 (M1P), and distal M1 (M1D), a total of 8 times per AC position, using the ingestion technique. The pinching technique was also examined using the 4x20mm stent. Results The average pulling force measured on M2 using the 4x20mm stent was 169.1mN with the AC docked in the proximal NoAsp position, 26.5mN with the AC at M1P, and 23.0mN at M1D (p&lt;0.0001). The difference in pulling force between M1P and M1D was not significant (p=0.472). The average pulling force exerted on M2 from pinching the 4x20mm stent with the AC at M1D, rather than ingestion of the stent at M1D, was 62.9mN. Average pulling force was noted to decrease from the first to the last run in most cases, with an average drop of 26.4% at the fourth run. Conclusion ADAPT and stent‐retrieval have recently been shown to be comparable in DMVO (1), however some studies have suggested a combined approach may reduce bleeding complications compared to stent‐retrieval alone (2). In our in‐vitro model, we demonstrated that positioning the AC in M1 (M1D or M1P) reduced the pulling force exerted by the stent‐retriever on M2 compared with AC placement in the cavernous carotid (NoAsp). The pulling force exerted from pinching the 4x20mm stent with the AC at M1D was higher than with the ingestion technique, for which the explanation is uncertain, but may be due to the additional friction in the M1 segment. Taken together, these findings suggest a combined approach decreases frictional pulling force during stent‐retrieval and is safer than SR alone. We also note that the pulling force of each stent decreased after its third usage, in line with the manufacturer’s instructions for use, which suggest no more than 3 retrievals per stent (3). Future experiments will compare a wider range of techniques using stents of varying sizes to better clarify factors associated with decreased pulling force in EVT.

Abstract 064: The Pushability of Commonly Used Microwires in Neuroendovascular Procedures

Introduction In distal and medium‐vessel occlusions (DMVOs), there are increasing opportunities to deliver devices through tortuous and medium sized arteries. However, this comes at the risk of microwire perforation during distal microcatheter advancement for navigation in these curved, slender vessels, leading to hemorrhagic complications. Currently, microwires with a range of stiffness levels are available. However, it is unclear how the variations in stiffness and the relative positioning of the microwire and microcatheter may affect the force applied to the vessel wall. Few studies have compared objective metrics across different commonly used devices. We sought to compare the pushability of various Synchro Select and Chikai microwires using both proximal and distal support. Methods In a moderate tortuosity, silicone flow model of the middle cerebral artery (MCA) branches, we tested 0.014” nitinol microwires (Synchro Select Soft, Standard, or Support), or 0.014” stainless steel microwires (Chikai, Black, and Black Soft) in a TrevoTrak 21 microcatheter docked either in the proximal M1 segment or distal M2 segment. Applied force was measured using an Imada force gauge DST‐1A at the M2 ten times for each experiment. The slope, measured in mN per mm, of the applied distal force during the maximal pushing period was calculated. Results The average slope of the pushing force within a distal microcatheter was 10.64 mN/mm with a Synchro Soft, 10.85 mN/mm with a Standard, and 15.28 mN/mm with a Support microwire (p &lt; 0.0001). The average slope of the pushing force in a proximal microcatheter was 1.61 mN/mm with a Synchro Soft, 3.15 mN with a Synchro Standard, and 3.87 mN with a Synchro Support microwire (p &lt;0.001). With the Chikai microwires, the average slope of the pushing force within a distal microcatheter was 12.48 mN/mm with a Chikai Black Soft wire, 12.82 mN/mm with a Chikai Black microwire, and 14.11 mN/mm using a Chikai microwire (p=0.801). Within a proximal microcatheter, the average maximal force was 2.42 mN/mm using a Chikai Black Soft wire, 3.16 mN/mm using Chikai Black, and 3.91 mN/mm using the Chikai wire (p &lt; 0.001). Conclusion This study demonstrated that stiffer microwires push the arterial wall with significantly greater force within a microcatheter close to the wall. Pushability of the microwire significantly dropped across all microwires when the microcatheter was positioned more proximally. This is the first known report of the pushability of commonly used microsystems in neuroendovascular procedures.