Segment Of Middle Cerebral Artery Research Articles

Development and Validation of a Flow-Dependent Endothelialized 3D Model of Intracranial Atherosclerotic Disease

Abstract Intracranial atherosclerotic disease (ICAD) is a major cause of stroke globally, with mechanisms presumed to be shared with atherosclerosis in other vascular regions. Due to the scarcity of relevant animal models, testing biological hypotheses specific to ICAD is challenging. We developed a workflow to create patient-specific models of the middle cerebral artery (MCA) from neuroimaging studies, such as CT angiography. These models, which can be endothelialized with human endothelial cells and subjected to flow forces, provide a reproducible ICAD model. Using imaging from the SAMMPRIS clinical trial, we validated this novel model. Computational fluid dynamics flow velocities correlated strongly with particle-derived flow, regardless of stenosis degree. Post-stenotic flow disruption varied with stenosis severity. Single-cell RNA-seq identified flow-dependent endothelial gene expression and specific endothelial subclusters in diseased MCA segments, including upregulated genes linked to atherosclerosis. Confocal microscopy revealed flow-dependent changes in endothelial cell proliferation and morphology in vessel segments related to stenosis. This platform, rooted in the specific anatomy of cerebral circulation, enables detailed modeling of ICAD lesions and pathways. Given the high stroke risk associated with ICAD and the lack of effective treatments, these experimental models are crucial for developing new ICAD-related stroke therapies.

Clinical Impact of Reperfusion Techniques and Occlusion Sites in Thrombectomy: Insights from the ASSIST Stroke Registry

BACKGROUND Mechanical thrombectomy has changed the landscape of acute ischemic stroke treatment, offering improved outcomes for patients with large vessel occlusions. The interplay between reperfusion techniques and occlusion sites remains a critical consideration in treatment decisions. This study investigates the impact of primary reperfusion techniques—stent retriever classic, stent retriever combination with aspiration, and direct aspiration—on procedural and clinical outcomes at different occlusion sites. METHODS Using data from the ASSIST registry, a prospective multinational initiative, patients with anterior circulation acute ischemic stroke with large vessel occlusions (n = 1477) were included. Three primary occlusion sites—M1 segment of the middle cerebral artery, M2 segment of the middle cerebral artery, and the internal carotid artery—were studied. Univariate tests and multivariable logistic regression models were used to assess associations between reperfusion techniques and procedural and clinical outcomes, including the expanded thrombolysis in cerebral infarction score and the modified Rankin Scale, stratified by occlusion site. RESULTS Achieving expanded thrombolysis in cerebral infarction ≥2c after first pass was lower in internal carotid artery occlusions (18.2%, P <0.0001) with direct aspiration alone compared with stent retriever classic (38.2%) or stent retriever combination with aspiration (43.3%), while no differences were seen for M1 segment of the middle cerebral artery ( P = 0.77) and M2 segment of the middle cerebral artery ( P = 0.29) occlusions. Bailout maneuvers, which were more frequent in the direct aspiration group for all occlusion sites, did not result in longer procedure times or different final recanalization outcomes in direct aspiration compared with stent retriever classic or stent retriever combination with aspiration. Overall, there were no differences in the rate of patients with modified Rankin Scale scores of 0–2 at 90 days. No differences in safety outcomes were observed. CONCLUSIONS This study provides insight into the complex relationship between reperfusion techniques and occlusion sites in patients with acute ischemic stroke and shows that certain techniques have advantages in certain occlusion sites. As the field evolves, further research is warranted to refine our understanding of these dynamics and inform clinical practice.

Abstract 65: Postpartum Alterations of Middle Cerebral Artery Reactivity and Hemodynamics in a Transgenic Rat Model of Preeclampsia

Evidence suggests that cerebrovascular disease is a leading cause of morbidity and mortality in women with preeclampsia (PE), however the mechanisms are unknown. In a transgenic rat displaying PE-like syndrome (TGA-PE: female transgenic for angiotensinogen mated to male transgenic for renin), we have shown postpartum alterations in cerebrovascular hemodynamics suggesting dysfunctional autoregulation. We hypothesize that impaired middle cerebral artery (MCA) reactivity contributes to the cerebrovascular dysfunction in this model. High frequency ultrasound was used to determine the pulsatility index (PI) of left MCA (LMCA). Vascular responses were studied in isolated segments of LMCA from SD (n= 12) and TGA-PE (n=8) two months post-delivery. Arteries were mounted on a Multi-Wire Myograph for determination of isometric force (USA-DMT). The contractile responses to K + 75 mM and endothelin-1 (ET-1, 10 -11 -10 -7 M) were measured in basal tone. Vasodilatory responses to acetylcholine (ACh, 10 -11 -10 -4 M) were determined in arteries pre-constricted with the thromboxane agonist U46619 (10 -7 M); the maximal response ( R MAX ) and sensitivity (pD 2 =-Log[EC 50 ]) were analyzed. Our data show that systolic blood pressures were elevated in TGA-PE versus SD at 2 months post-delivery (144.9±2.7 vs. 118.4±2.5, p<0.05; n=10-19). However, the PI was lower in TGA-PE vs. SD (0.96±0.05 vs. 1.31±0.06; p<0.05, n=8-13). No differences in basal tone of MCA segments were observed, whereas TGA-PE arteries displayed a lower optimal diameter (175±4 μm vs. 217±4 μm; p<0.05) and a lower response to K + (0.85±0.11 vs. 1.29±0.1 mN/mm; p<0.05) compared to SD. Vasodilatation to acetylcholine was similar (ACh MAX : 79±8 vs. 70±9%) with a lower sensitivity (pD 2 : 5.2±0.1 vs. 6.7±0.4; p<0.05) in TGA-PE. The contractile response to ET-1 was increased in TGA-PE arteries (ET-1 MAX : 159±7 vs. 129±6 % K MAX ; p<0.05) with no differences in sensitivity (pD 2 : 8.8±0.1 vs. 8.9±0.1). Our data demonstrate structural and functional differences in MCA from TGA-PE vs. SD at 2 months postpartum. In addition to a smaller functional diameter, a lower non-receptor dependent contraction may explain the lower resistance of MCA observed in the preeclamptic model. We conclude that attenuated vasodilatory and increased contractile responses of MCA could promote cerebrovascular dysfunction in this model, and that these adaptations may contribute to cerebrovascular pathology in postpartum preeclamptic state. Supported by NIH 1R01HL155420

Combining the deployment of only the distal basket segment of the EMBOTRAP III and an aspiration catheter for M2 occlusions: the ONE-SEG technique.

Endovascular therapy (EVT) for distal medium vessel occlusions requires prioritizing effectiveness and safety. We developed a technique combining the deployment of only the distal basket segment of the EMBOTRAP III and an aspiration catheter (AC) for M2 occlusions, called the "ONE-SEG technique," and evaluated its clinical and technical impacts. This was a retrospective review of 30 consecutive patients with M2 segment middle cerebral artery occlusion treated using the ONE-SEG technique. This method involves deploying the EMBOTRAP III through a microcatheter in only one segment and guiding the AC to the M2 origin or distal M1. The rates of final-pass expanded thrombolysis in cerebral infarction (eTICI) scores of 2c/3 or 2b/2c/3, safety (symptomatic intracranial hemorrhage [sICH]), and clinical outcomes (modified Rankin Scale [mRS] score 0-2, 0-3 at 90 days, and mortality at 90 days) were evaluated. Of the 30 cases, 36.7% were female, and the mean age was 75.6 ± 11.0 years. The ONE-SEG technique was used for 17 cases (56.7%, median NIHSS 10 [5-15.5]) with primary M2 occlusion and 13 cases (43.3%, median NIHSS 20 [14-22.5]) with secondary M2 occlusion after proximal thrombus removal. The successful final reperfusion rate (eTICI 2b/2c/3) was 90% overall (27/30 cases). One case (3.3%) developed sICH with secondary M2 occlusion. At 3 months, mRS scores 0-2 were seen in 64.7% of patients with primary M2 occlusion (11/17 cases) and in 23.1% (3/13 cases) with secondary M2 occlusion. EVT using the ONE-SEG technique appears to be safe and effective for M2 occlusion.

Using High-Resolution Vessel Wall Magnetic Resonance Images in a Patient of Intracranial Artery Dissection Related Acute Infarction.

Acute ischemic stroke in young adults typically carries significant implications for morbidity, mortality, and long-term disability. In this study, we describe the case of a 34-year-old male with no prior medical history who presented with symptoms of right-sided weakness and slurred speech, suggesting an acute ischemic stroke. Initial CT angiography revealed an occlusion in the left M2 segment middle cerebral artery (MCA). The occlusion was successfully recanalized through emergent endovascular thrombectomy, which also identified a dissection as the cause of the stroke. Follow-up assessments at 3 days and three months, which included advanced vessel wall MRI, highlighted the critical role of intracranial artery dissection in strokes among young adults and provided essential images for ongoing evaluation.

Comparing Outcomes of Thrombectomy Versus Intravenous Thrombolysis Based on Middle Cerebral Artery M2 Occlusion Features.

Current evidence provides limited support for the superiority of endovascular thrombectomy (EVT) in patients with M2 segment middle cerebral artery occlusion. We aim to investigate whether imaging features of M2 segment occlusion impact the effectiveness of EVT. We conducted a retrospective cohort study from January 2017 to January 2022, drawing data from the CASE II registry (Computer-Based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation), which specifically documented patients with acute ischemic stroke presenting with M2 segment occlusion undergoing reperfusion therapy. Patients were stratified into the intravenous thrombolysis (IVT) group (IVT alone) and EVT group (IVT plus EVT or EVT alone). The primary outcome was a modified Rankin Scale score 0 to 2 at 90 days. Secondary outcomes included additional thresholds and distribution of modified Rankin Scale scores, 24-hour recanalization, early neurological deterioration, and relevant complications during hospitalization. Safety outcomes encompassed intracranial hemorrhagic events at 24 hours and mortality at 90 days. Binary logistic regression analyses with propensity score matching were used. Subgroup analyses were performed based on the anatomic site of occlusion, including right versus left, proximal versus distal, dominant/co-dominant versus nondominant, single versus double/triple branch(es), and anterior versus central/posterior branch. Among 734 patients (43.3% were females; median age, 73 years) with M2 segment occlusion, 342 (46.6%) were in the EVT group. Propensity score matching analysis revealed no statistical difference in the primary outcome (odds ratio, 0.860 [95% CI, 0.611-1.209]; P=0.385) between the EVT group and IVT group. However, EVT was associated with a higher incidence of subarachnoid hemorrhage (odds ratio, 6.655 [95% CI, 1.487-29.788]; P=0.004) and pneumonia (odds ratio, 2.015 [95% CI, 1.364-2.977]; P<0.001). Subgroup analyses indicated that patients in the IVT group achieved better outcomes when presenting with right, distal, or nondominant branch occlusion (Pall interaction<0.05). Our study showed similar efficiency of EVT versus IVT alone in acute M2 segment middle cerebral artery occlusion. This suggested that only specific patient subpopulations might have a potentially higher benefit of EVT over IVT alone. URL: https://clinicaltrials.gov; Unique identifier: NCT04487340.

Geometry and Symmetry of Willis' Circle and Middle Cerebral Artery Aneurysms Development.

Background: A relationship between the geometry and symmetry of Willis' circle and intracranial aneurysms was reported for anterior communicating and posterior communicating (PCom) aneurysms. A similar association with the middle cerebral artery (MCA) aneurysms instead appeared weaker. Methods: We reviewed 432 patients from six Italian centers with unilateral MCA aneurysms, analyzing the relationship between the caliber and symmetry of Willis' circle and the presence of ruptured and unruptured presentation. CT-angiograms were evaluated to assess Willis' circle geometrical characteristics and the MCA aneurysm side, dimension and rupture status. Results: The hypoplasia of the first segment of the anterior cerebral artery (A1) was in approximately one-quarter of patients and PCom hypoplasia was in almost 40%. About 9% had a fetal PCom ipsilaterally to the aneurysm. By comparing the aneurysmal and healthy sides, only the PCom hypoplasia appeared significantly higher in the affected side. Finally, the caliber of the internal carotid artery (ICA) and the first segment of MCA (M1) caliber were significantly greater in patients with unruptured aneurysms, and PCom hypoplasia appeared related to the incidence of an ipsilateral MCA aneurysm and its risk of rupture. Conclusions: Although according to these findings asymmetries of Willis' circle are shown to be a risk factor for MCA aneurysm formation and rupture, the indifferent association with ipsilateral or contralateral hypoplasia remains a datum of difficult hemodynamic interpretation, thereby raising the concern that this association may be more casual than causal.

EnDovascular Therapy Plus Best Medical Treatment (BMT) Versus BMT Alone for MedIum distal VeSsel Occlusion sTroke (DISTAL): An international, multicentre, randomized-controlled, two-arm, assessor-blinded trial.

Whether endovascular therapy (EVT) in addition to best medical treatment (BMT) in people with acute ischemic stroke (AIS) due to a medium distal vessel occlusion (MDVO) is beneficial remains unclear. To determine if people experiencing an AIS due to an isolated MDVO (defined as the co- or non-dominant M2 segment, the M3 or M4 segment of the middle cerebral artery, the A1, A2, or A3 segment of the anterior cerebral artery or the P1, P2 or P3 segment of the posterior cerebral artery) will have superior outcome if treated with EVT in addition to BMT compared to BMT alone. To randomize 526 participants 1:1 to EVT plus BMT or BMT alone. A multicentre, international, prospective, randomized, open-label, blinded-endpoint (PROBE) superiority trial. The primary efficacy endpoint is the distribution of disability levels on the modified Rankin Scale at 90 days. Secondary clinical efficacy outcomes include normalized change in National Institutes of Health Stroke Scale score from baseline to day 1, cognitive outcome at 90 days, and health-related quality of life at 90 days. Safety outcomes include all serious adverse events, symptomatic intracranial hemorrhage within 24 h, and all-cause mortality up to 90 days. Secondary imaging outcomes include successful reperfusion at end of EVT procedure and recanalization of target artery at 24 h. DISTAL will inform physicians whether EVT in addition to BMT in people with AIS due to a MDVO is more efficacious than BMT alone.

Spiral time-of-flight magnetic resonance angiography for intracranial vascular imaging: performance compared to conventional Cartesian angiogram.

Computed tomography angiography (CTA) and digital subtraction angiography (DSA) usually raise the risk of potential malignancies with cumulative radiation doses. Current time-of-flight magnetic resonance angiography (TOF-MRA) (dubbed as cTOF), which is based on Cartesian sampling mode, may show limited diagnostic conspicuity at sinuous or branching regions. It is also prone to relatively high false positive diagnoses and undesirable display of distal intracranial vessels. This study aimed to use spiral TOF-MRA (sTOF) as a noninvasive alternative to explore possible improvement, such that the application of magnetic resonance angiography (MRA) can be extended to facilitate clinical examination or cerebrovascular disease diagnosis and follow-up studies. Initially, 37 patients with symptoms of dizziness or transient ischemic attack were consecutively recruited for suspected intracranial vascular disease examination from Zhongshan Hospital of Xiamen University between July 2020 and April 2021 in this cross-sectional prospective study. After excluding 1 patient with severe scanning artifacts, 1 patient whose scanning scope did not meet the requirement, and 1 patient with confounding tumor lesions, a total of 34 participants were included according to the inclusion and exclusion criteria. Each participant underwent intracranial vascular imaging with both sTOF and cTOF sequences on a 3.0 T MR scanner with a conventional head-neck coil of 16 channels. Contrast CTA or DSA was also performed for 15 patients showing pathology. Qualitative comparisons in terms of image quality and diagnostic efficacy ratings, quantitative comparisons in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), vessel length, and sharpness were evaluated. Pair-wise Wilcoxon test was performed to evaluate the imaging quality derived from cTOF and sTOF acquisitions and weighted Cohen's Kappa was conducted to assess the rating consistency between different physicians. Compared to cTOF, sTOF showed better performance with fewer artifacts. It can effectively alleviate false positives of normal vessels being misdiagnosed as aneurysm or stenosis. Improved conspicuity was observed in cerebral distal regions with more clearly identifiable vasculature at finer scales. Quantitative comparisons in selected regions revealed significant improvement of sTOF in SNR (P<0.01 or P<0.001), CNR (P<0.001), vessel length (P<0.001), and sharpness (P<0.001) as compared to cTOF. Besides, sTOF can depict details of M1 and M2 segments of middle cerebral artery (MCA) at metallic implant region, showing its resistance to magnetic susceptibility. The sTOF shows higher imaging quality and lesion detectability with reduced artifacts and false positives, representing a potentially feasible surrogate in intracranial vascular imaging for future clinic routines.

Failure of Evolutionary Pruning: a Case Report on a Young Adult with Rare Twig-like Middle Cerebral Artery and Its Implications on Worse Outcomes

Twig-like middle cerebral artery (MCA) is a rare intracranial vascular pathology that was hypothesized to be an arrest on the evolutionary fusion of the plexiform arterial network in the forebrain into a single MCA artery. This anomaly predisposes affected individuals to worse outcomes such as intracranial hemorrhages due to its association with aneurysms and primitive plexiform arterial systems that are prone to rupture. In this case report, a 30-year-old male had a loss of consciousness after serving as a ceremonial guard for four straight days. The patient did not have any neurologic localizing signs but presented with occasional generalized headaches relieved by pain medications. Cranial MRA showed suspicious stenosis of the left MCA. A cranial computed tomography angiogram showed complete stenosis of the M1 segment of the left MCA. Digital subtraction angiography was also done, which confirmed the complete occlusion of the said segment with collaterals from the A1 of the anterior cerebral artery supplying the distal portions of the left MCA. These findings, hence, suggested the presence of a twig-like MCA. In this article, the prevalence, pathogenesis, arrival to the diagnosis, and clinical relevance shall be discussed.

Long-term outcomes after formation of a low-flow STA-MCA bypass for treatment of symptomatic occlusion of the internal carotid artery

Aim. To evaluate short‑ and long‑term effectiveness of low‑flow bypass between superficial temporal artery and M4 segment of middle cerebral artery (low‑flow STA‑MCA bypass) in patients with symptomatic occlusion of the internal carotid artery (ICA).Materials and methods. Between 2016 and 2019 at the Department of Neurosurgery of the N. V. Sklifosovsky Research Institute of Emergency Medicine, 54 patients who underwent low‑flow STA‑MCA bypass formation at the side of symptomatic ICA occlusion between 2013 and 2015 were examined. Symptomatic ICA occlusion was more common in men than in women (7:1 ratio). Patient age varied between 48 and 73 years (mean age was 62 years).During low‑flow STA‑MCA bypass formation surgery for symptomatic ICA occlusion, intraoperative flowmetry was used in 52 (96 %) patients, in 2 (4 %) patients this diagnostic method was impossible to perform due to technical difficulties. The main examination methods in the long term after cerebral revascularization were evaluation of neurological status dynamics per the National Institute of Health Stroke Scale (NIHSS); modified Rankin scale; Rivermead mobility index; computed tomography angiography of the extra‑intracranial arteries; ultrasound (US) examination of the STA‑MCA bypass for eval uation of linear and volumetric blood flow velocities; single‑photon emission computed tomography. The type and size of trephination were evaluated, and operative time was taken into account.The patients were divided into 3 groups: group 1 included patients with follow‑up period of 1–2 years after cerebral revascularization, group 2 – 3–4 years, group 3 – 5–6 years. All results were compared to preoperative, early, and longterm measurements.Results. In the long‑term postoperative period between 1 and 6 years after cerebral revascularization, 54 patients were examined. Computed tomography angiography and US showed functioning STA‑MCA bypass in 53 (98 %) patients. According to single‑photon emission computed tomography of the brain, regional cerebral blood flow in the longterm postoperative period varied between 28 and 40 mL / 100 g / min, median regional cerebral blood flow in the long‑term postoperative period was 38 mL / 100 g / min. Intraoperative flowmetry was performed in 52 (96 %) patients, median was 15.5 mL / min. US showed that linear blood flow velocity in the STA‑MCA bypass varied between 20 and 95 cm / s, median was 49 cm / s. Volumetric blood flow varied between 30 and 85 mL / min with median of 75 mL / min.Resection trephination was performed in 36 (67 %) patients, mean size of trephination hole was 3 cm3. In the study, operative time was measured: mean value was 212 min; no significant correlation between operative time and trephination size was observed.Improved neurological status was observed in all study groups. Per the NIHSS, in group 1 (1–2 years) improvement was observed in 59 % of patients, in group 2 (3–4 years) in 48 %, in group 3 (5–6 years) in 47 %. Per the modified Rankin scale, in group 1 improvement was observed in 36.4 % of patients, in group 2 – in 48 %, in group 3 – in 42.9 %. Per the Rivermead mobility index, in group 1 improvement was observed in 63.3 % patients, in group 2 – in 56 %; in group 3 – in 57.1 %. The best outcomes were observed in group 1 (63.3 %).Conclusion. Instrumental diagnostic methods and evaluation of neurological status showed positive dynamics both in the postoperative period and in long‑term period between 1 and 6 years after low‑flow STA‑MCA bypass formation. In the long term, repeat abnormalities of cerebral blood flow of ischemic type and repeat transient ischemic attacks were not observed. Correct selection of patients in the preoperative period and comprehensive treatment including drug therapy in the postoperative and long‑term periods allow to prevent repeat ischemic cerebrovascular disease and therefore improve patients’ quality of life.

Technical and clinical outcomes of thrombectomy in patients with acute medium vessel occlusion and large vessel occlusion; sub-analyses of Japan Trevo registry

BackgroundLittle is known about endovascular therapy (EVT) for patients with medium vessel occlusion (MeVO) and more work is needed to establish its efficacy and to understand hemorrhagic complications. MethodsWe analyzed the Japan Trevo Registry, which enrolled patients with acute stroke who underwent EVT using Trevo Retriever alone or in combination with an aspiration catheter. The primary outcome was effective reperfusion, and the secondary outcome was modified Rankin scale 0–2 at 90 days. Safety outcomes, including intracranial hemorrhage (ICH), were evaluated using a subgroup analyses focused on any ICH. ResultsAmong 1041 registered patients, 1025 patients were analyzed. 253 patients had MeVOs, and the majority (89.3%) had middle cerebral artery segment 2 (M2). The median National Institutes of Health Stroke Scale scores at admission were 15 and 19 for the MeVO and LVO groups (p < 0.0001). The primary outcome was 88.9% in MeVO vs. 91.8% in LVO group: adjusted odds ratio (aOR) [95% confidence interval (CI)] 0.60 [0.35–1.03], p = 0.07, and the secondary outcome was 43.2% vs. 42.2%, and the aOR [95%CI] was 0.70 [0.48–1.002], p = 0.051. However, the incidence of any ICH was more prominent in MeVO than in LVO group (35.7% vs. 28.8%, aOR [95%CI] 1.54 [1.10–2.15], p = 0.01). In subgroup analyses, the incidences of any ICH in MeVO group were generally higher than those in LVO group. ConclusionsThe effective reperfusion rate did not differ significantly between MeVO and LVO groups. Future development of devices and treatments for MeVO with fewer hemorrhagic complications is desirable.

Feasibility of super-bore 0.088″ mechanical thrombectomy in M1 vessels smaller than 8 French: Experience in 20 consecutive cases.

Superbore 0.088″ catheters provide a platform for optimizing aspiration efficiency and flow control during stroke mechanical thrombectomy procedures. New superbore catheters have the distal flexibility necessary to navigate complex neurovascular anatomy while providing the proximal support of traditional 8F catheters. The safety and feasibility of Zoom 88™ superbore angled-tip catheters in the middle cerebral artery (MCA) segments smaller than the catheter diameter have not been previously described. Twenty consecutive cases of acute MCA mechanical thrombectomy were retrospectively identified from the senior authors' prospectively maintained Institutional Review Board-approved database, in which the Zoom 88 (Imperative Care, Campbell, CA) catheter was successfully navigated to at least the M1 segment. Patient demographics, procedural details, and periprocedural information were analyzed. Rates and averages (standard errors) are generally reported. The average National Institutes of Health Stroke Scale at presentation and age were 15 ± 2 and 73 ± 3 years, respectively. The M1 and M2 occlusions were evenly distributed. The average M1 measurements before thrombectomy ranged from 2.36 ± 0.07 mm proximally to 2.00 ± 0.11 mm distally, and after thrombectomy, they ranged from 2.34 ± 0.07 mm proximally to 1.97 ± 0.10 mm distally. First-pass modified thrombolysis in cerebral infarction (mTICI) 2C/3 recanalization was achieved in 40% of cases, and final mTICI 2C/3 recanalization was achieved in 90% of cases. A single case of mild vasospasm was managed with verapamil. No hemorrhagic or periprocedural complications were noted. Superbore 0.088″ catheters with flexible distal segments can be safely navigated to the MCA to augment mechanical thrombectomy even when the MCA segment is smaller than the catheter.

A foreign body that has been left for 20 years causes a pseudoaneurysm of the middle cerebral artery: a case report

BackgroundWe report a patient with extensive subarachnoid hemorrhage caused by the rupture of a middle cerebral artery pseudoaneurysm from a foreign body that had been left for two decades.Case presentationA 74-year-old male patient from Han nationality was admitted to the emergency department of our hospital with impaired consciousness for 1 hour. Cranial computed tomography examination indicated a massive subarachnoid hemorrhage with intraventricular blood accumulation, and a high-density short strip dense shadow was seen in the M1 segment of the right middle cerebral artery, considering the possibility of a foreign body. Subsequently, a cerebral angiography was suggested; the foreign body was seen through the right middle cerebral artery, and the aneurysm was seen in the lower wall, so a pseudoaneurysm was considered. The emergent surgical intervention involved the clipping of the pseudoaneurysm and intracranial extraction of the foreign body. Unfortunately,the patient ultimately expired due to severe pulmonary infection.ConclusionIntracranial pseudoaneurysm caused by foreign body has been rarely reported previously, and microsurgical treatment of an intracranial pseudoaneurysm caused by a foreign body is a good choice.

Abstract TP219: Outcomes and Differences by Occluded Vessel in the Endovascular Treatment for Acute Ischemic Stroke Patients With Medium Vessel Occlusion

Introduction: The outcomes of mechanical thrombectomy (MT) for patients with acute ischemic stroke (AIS) caused by medium vessel occlusions (MeVOs) in different vessels remains unknown. The aim of this study is to investigate MT outcomes in AIS patients with isolated MeVOs in different occluded vessel segments using the data from an ongoing international multicenter registry, the Stroke Thrombectomy and Aneurysm Registry (STAR). The aim of this study is to investigate MT outcomes in AIS patients with isolated MeVOs in different occluded vessel segments using the data from an ongoing international multicenter registry, the Stroke Thrombectomy and Aneurysm Registry (STAR). Methods: 110 AIS patients with MeVO who undertook MT between January 2010 and December 2022 were retrospectively investigated. MeVO was defined as isolated occlusion of the A2 or A3 (A23O) segment of the anterior cerebral artery, M3 segment of the middle cerebral artery (M3O), and P2 or P3 segment of the posterior cerebral artery (P23O). The primary outcome measure was a 90-day modified Rankin score (mRS) 0-2. The 90-day mRS 0-1, any intracranial hemorrhage, symptomatic intracranial hemorrhage, and 90-day mortality were used as secondary outcomes. Outcomes were compared between A23O, M3O, and P23O. Results: Median (interquartile range) age was 68.3 (58.4-76.0) years and 49 patients were female (46.7%). MeVO included 17 A23O (15.5%), 60 M3O (54.5%), and 33 P23O (30.0%).Compared to patients with A23O (17.7%), those with M3O (56.7%) and P23O (45.5%) had a higher proportion of 90-day mRS 0-2 (M3O, adjusted odds ratio 10.3, 95% confidence interval 1.71-62.2, p = 0.01; P23O adjusted odds ratio 8.86, 95% confidence interval 1.32-59.3, p =0.02). Other outcomes showed no significant differences. Conclusions: This study indicates A2O might be related to poorer outcomes compared to M3O and P23 in MT treatment for AIS patients due to isolated MeVO. Efforts should be aimed at improving outcomes following A23O to match those at other MeVO locations.

Abstract TP146: Collateral Status-Based Model for Hemorrhagic Transformation in Successfully Recanalized Medium Vessel Occlusions

Introduction: Collateral status imaging parameters are associated with predicting hemorrhagic transformation (HT) in acute ischemic stroke caused by large vessel occlusions. The purpose of this investigation is to examine the association between imaging biomarkers of poor collateral status and HT occurrence in distal medium vessel occlusion (DMVO) stroke patients. Methods: Data from two comprehensive stroke centers between 2019 and 2023 were retrospectively reviewed for acute ischemic stroke patients with M2-M4 segment middle cerebral artery occlusions. For inclusion, patients must have been successfully recanalized by mechanical thrombectomy with or without intravenous thrombolytic and ultimate modified thrombolysis in cerebral infarction (mTICI) score 2B/2C/3. Occurrence of HT was determined from post-interventional imaging, and HT subtype was defined by the ECASS 2 criteria. Significant univariate predictors were included in a forward stepwise logistic regression for outcome of HT, and adjusted odds ratios (aOR) were reported. Results: Of 60 patients, 17 (28.3%) patients had HT. Average age was 74 [IQR 64-81] years, 34 (56.7%) were female. The multivariate model (area under curve = 0.93) had three significant predictors: diabetes mellitus (aOR 36.5, 95% CI 4.9-272.2, p&lt;0.001); proximal versus distal occlusion (reference: distal, aOR 0.06, 95% CI 0-0.4, p=0.006); CBV index (aOR 0.0002, 95% CI 0-0.1, p=0.007). Conclusions: Lower CBV index (a marker of poor collateral status), presence of distal occlusions, and history of diabetes mellitus are significant predictors associated with increased odds of HT in successfully recanalized DMVO stroke patients. Larger studies are necessary to further validate our findings.

Contrast-induced encephalopathy after an embolization procedure for a cerebral aneurysm in a female with subarachnoid hemorrhage: a case report

BackgroundContrast-induced encephalopathy (CIE) is a rare complication during or after angiography, usually transient and reversible. CIE diagnosis is challenging due to the absence of no formal diagnostic criteria. CIE can mimic stroke symptoms, including visual disturbances, seizures, confusion, coma, and focal neurological deficits. This case reports neurological deficit reversal in a CIE patient due to the embolization of an intracranial aneurysm, the second angiographic procedure in six days.Case presentationA 77-year-old woman was admitted to the hospital for headaches. The cerebral computed tomography (CT) scan indicated a subarachnoid hemorrhage. The first digital subtraction angiography (DSA) identified an aneurysm of 4 mm ∗ 3 mm in size in the M1 segment of the right middle cerebral artery (MCA). Then, embolization surgery was performed for the cerebral aneurysm, which was successful. However, the patient had post-operative headaches, slurred speech, epilepsy, limb weakness, and delirium post-procedure. The non-contrast cerebral CT indicated widespread edema in the right cerebral hemisphere. The patient was diagnosed with CIE and treated with symptomatic supportive therapy. Eventually, the patient’s neurological deficits and cerebral edema improved significantly.ConclusionsThe current case emphasized the importance of early diagnosis and symptomatic treatment of CIE. Thus, CIE should be the first consideration during the differential diagnosis of a patient having acute neurological impairment after repeated DSA.

A "Radial Ready" Tricoaxial Setup for Anterior Circulation Mechanical Thrombectomy: Technical Aspects and Preliminary Results.

Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke (AIS) due to large vessel occlusion (LVO). The choice of a transradial approach (TRA) for anterior circulation LVOs is still debatable; the use of a specific tricoaxial system could help mitigate numerous issues related to transradial MT. From November 2022 to November 2023, 22 patients underwent TRA-MT for anterior circulation LVOs, both as first-line and rescue from transfemoral approach (TFA) failure, with the same triaxial setup consisting of a 7F introducer sheath, 7F guide catheter, and aspiration catheters ranging from 5.5F to 5F in relation to the occlusion site. Choice of thrombectomy technique was at operator discretion. Patients' demographic data, clinical presentation, treatment details, complications, rate of crossover to TFA, successful revascularization (modified thrombolysis in cerebral infarction [mTICI] score ≥2b), and good clinical outcome at 3 months (modified Rankin scale [mRS] 0-2) were reported. Of 20 patients selected, 10 (50%) had occlusion of M1 segment of middle cerebral artery (MCA), 6 (30%) of internal carotid artery (ICA) terminus, and 4 (20%) with M2 MCA occlusions; 12/20 (60%) were right-sided occlusions and 8/20 (40%) were left-sided. The mean National Institutes of Health Stroke Scale score was 9.25 at admission. Successful revascularization to mTICI 2b-3 was achieved in 18/20 patients (90%). Intracranial complications were reported in 2 (10%) patients. Rate of radial artery occlusion at 24 hours was 10,6%; no access-site haemorrhagic complications were reported. Symptomatic intracranial hemorrhage occurred in 2 (10%) patients. mRS score 0-2 at 3 months was 50%. The high technical effectiveness and good safety profile of this specific tricoaxial setup for TRA-MT in AIS, even for large proximal LVOs, could constitute a viable alternative to TFA-MT in selected cases.

Twig-like middle cerebral artery as a variety of isolated middle cerebral artery disease with new vessel formation: illustrative case.

Twig-like middle cerebral artery (T-MCA) is reported as a rare vascular anomaly characterized by reconstitution of the M1 segment of the middle cerebral artery (MCA) by a plexiform network of small vessels. Although it is generally believed that the etiology of T-MCA is an embryological persistence, some investigators have suggested that T-MCA may be a secondary consequence. Here, the authors report a second case of de novo T-MCA formation and reconsider the concept of T-MCA in connection with isolated MCA disease. A 40-year-old man's brain magnetic resonance imaging (MRI) checkup showed moderate stenosis of the M1 segment of the left MCA. Annual MRI follow-up was planned, and when performed 1 year later, it showed occlusion of the M1 segment of the left MCA. Cerebral angiography revealed occlusion of that M1 segment with abnormal arterial networks. This case was diagnosed as de novo T-MCA. The patient has remained asymptomatic for 2 years. The reports of de novo T-MCA indicate that acquired factors may be involved in the pathogenesis of T-MCA. We suggest that T-MCA should be defined as a variety of isolated MCA disease with new vessel formation.

New evidence for fractional pressure ratio prediction by pulsatility index from transcranial Doppler in patients with symptomatic cerebrovascular stenosis disease.

The pulsatility index (PI) derived from transcranial Doppler (TCD) assessment may represent the cerebral resistance and altered cerebral blood flow. The purpose of this study was to assess the performance of the TCD PI in correlation with wire-based fractional pressure ratio (FPR). This study included 33 patients with symptomatic atherosclerotic lesions of the extracranial and intracranial large arteries, specifically the internal carotid artery, middle cerebral artery (MCA), vertebral artery (VA) V4 segment, and basilar artery (BA), all of which exhibited luminal stenosis ranging from 50% to 70%. TCD was performed prior to angiography in order to determine the flow distal to the lesion. We performed cerebrovascular angiography with a pressure wire to measure the FPR of vessels with stenotic lesions. Bland-Altman analysis and ordinal least square (OLS) linear regression were used to quantify the correlation between PI and FPR. A total of 42 TCD data points were analyzed. At the TCD locations distal to the lesions, the correlation coefficients were no less than 0.90%, with almost all P values <0.001, which indicated very strong positive correlations; the exception to this was the distal TCD for MCA segment lesions (r=0.897; P=0.015) and VA V4 segment (r=0.964; P=0.036). The Bland-Altman plot demonstrated a small difference (0.003) between the distal TCD PI and the FPR, with an acceptable 95% confidence interval [95% confidence interval (CI): 0.06-0.12]. The PI obtained through TCD assessment distal to the stenotic lesion exhibited a correlation with the FPR computed using pressure wire measurements.