超急性期中大脳動脈塞栓症に対する塞栓除去術

PurposeIn acute middle cerebral artery (MCA) occlusion, collateral vessels provide retrograde supply to the occluded territory. We hypothesized that such collateral flow reduces perfusion of the non-occluded donor region (steal effect).Materials and MethodsPatients with an MCA occlusion with opacification of both ipsi- and contralateral anterior cerebral arteries (ACA) on angiography prior to endovascular treatment were selected. Arteriovenous transit time (AVTT) for both ACA territories was compared for different grades of collateral supply to the MCA territory. In addition, the influence of diabetes and hypertension was analyzed. After successful revascularization, AVTT was re-assessed to determine reversibility.ResultsForty-one patients were analyzed. An AVTT of 8.6 seconds (standard deviation [SD] 2.4 seconds) was seen in the ACA territory of the affected hemisphere in comparison to 6.6 seconds (SD 2.1 seconds) for the contralateral side (P<0.001). A more prolonged (but not significant) AVTT was seen in cases with a higher collateral grade. No difference in AVTT was seen in patients with diabetes or hypertension. After successful MCA revascularization, AVTT delay was 7.4 seconds (SD 2.1 seconds).ConclusionA cerebral steal effect occurs in patients with an acute MCA occlusion, probably related to augmented flow to the penumbra area.

Backgound: Flow diversion (FD) can occur with an acute middle cerebral artery (MCA) occlusion. FD is thought to represent the collateral blood flow to the occluded MCA territory, but it is unclear whether or not FD lessens the stroke severity or leads to improved outcome. Methods: Patients with a proximal MCA occlusion were selected from the CLOTBUST trial data bank. FD to the anterior or posterior cerebral artery was determined using transcranial Doppler ultrasound. Stroke severity and clinical improvement were measured using the National Institutes of Health Stroke Scale (NIHSS) scores. Results: We evaluated 47 patients with an isolated M1 MCA occlusion who received intravenous tissue-type plasminogen activator (t-PA) within 3 h of symptom onset. FD was present in 83% of the patients. Median baseline NIHSS scores were 15.5 in the FD– group and 18 in the FD+ group (n.s.). Complete recanalization rates were 25 and 25.6% (n.s.). In 35 patients with a persistent occlusion, the average NIHSS score reduction was 22% (FD+) and 0.52% (FD–) during 90 min after t-PA bolus (p = 0.017), and 29 versus –25% during the first 24 h after the t-PA bolus, respectively (p = 0.01). Conclusions: In patients with persistent MCA occlusions after thrombolytic treatment, arterial blood flow diversion is associated with earlier and better neurological improvement. FD has protective effects on the ischemic brain tissue with persistent MCA occlusion.

Mechanical Thrombectomy of Acute Middle Cerebral Artery Occlusion Using Trans-Anterior Communicating Artery Approach.

BACKGROUNDSpontaneous thrombosis of a saccular, unruptured, intracranial aneurysm is rare in nongiant aneurysms. Herein, the authors present a case of acute middle cerebral artery occlusion (MCO) caused by spontaneous thrombus of a small internal carotid artery (ICA) aneurysm.OBSERVATIONSA 68-year-old woman presented with increased somnolence, right-sided hemiplegia, hemispatial neglect, and total aphagia. Left MCO and a small left ICA aneurysm were suspected based on magnetic resonance angiography (MRA). The authors detected early ischemic lesions from diffusion-weighted imaging (DWI). The DWI–Alberta Stroke Program Early Computed Tomography Score was 6. T2*-weighted imaging (T2*WI) showed a thrombus, the so-called susceptibility vessel sign, at the left MCO site. Another suspected thrombus was also found in the ipsilateral ICA aneurysm. The authors treated acute phase MCO with mechanical thrombectomy (MT), after which secondary stroke prophylaxis consisting of warfarin potassium was started. Since follow-up T2*WI showed the thrombus had disappeared from the left ICA aneurysm and the whole aneurysm was clarified by MRA, coil embolization was performed. After coil embolization, there was no ischemic recurrence.LESSONSAneurysms are infrequently found proximal to occlusion sites during MT. If the proximal aneurysm is a potential embolic source, treatment of the said aneurysm may prevent stroke.

Introduction: Selecting thrombectomy techniques for acute ischemic stroke due to large vessel occlusion significantly affects outcomes and costs. This study introduces the Bifurcation-Invisible (BI) sign identified on initial microcatheter angiogram in acute middle cerebral artery occlusions before endovascular thrombectomy. We aimed to evaluate whether this sign is associated with better angiographic outcomes using contact aspiration (CA) versus stent retriever (SR). Methods: In this study, we reviewed 285 cases of acute M1-segment middle cerebral artery (M1-MCA) occlusions treated with SR or CA. Angiographic success was evaluated using modified Thrombolysis In Cerebral Infarction (mTICI) scores after the first attempt, clinical outcomes by 90-day modified Rankin Scale (mRS) scores, and procedural costs were analyzed. Categorical variables were analyzed using χ2 or Fisher’s exact test, and continuous variables using Student’s t test or Mann-Whitney U test. Subgroup multivariate logistic analysis and interaction tests were conducted, with post hoc analysis applying Bonferroni correction. Results: BI-positive patients treated with CA had higher first-pass reperfusion rates (mTICI 2b-3: 64.0% vs. 41.3%, p = 0.005; Bonferroni-corrected p = 0.030) and 19.8% lower device costs (p < 0.05) than those treated with SR. BI-positive CA patients had higher first-pass reperfusion rates (mTICI 2b-3: 64.0% vs. 32.1%; p < 0.001; Bonferroni-corrected p = 0.002) and a 39.9% reduction in device costs (p < 0.05) than BI-negative patients. The interaction tests showed significant interactions between the presence of BI and CA for first-pass reperfusion rates (p = 0.007) and device costs (p < 0.001). Conclusion: The BI sign, a refined version of the branching-site occlusion sign identified via microcatheter angiography, could guide the selection of CA, improving recanalization rates and reducing costs in MCA occlusions.

FLAIR vascular hyperintensity with DWI for regional collateral flow and tissue fate in recanalized acute middle cerebral artery occlusion

We describe our experience in which a retrievable Enterprise stent was used as a temporary recanalization and embolectomy device in an acute middle cerebral artery (MCA) occlusion after urgent stenting for ipsilateral carotid artery stenosis.

Response

BackgroundAcute bilateral occlusion of the middle cerebral artery (MCA) is a very rare condition, and most cases are accompanied by a poor prognosis. However, mechanical thrombectomy (MT) for bilateral MCA is challenging. Here, we report a case of acute unilateral MCA occlusion with sequential acute occlusion of the bilateral MCA during intravenous thrombolysis (IVT). We urgently performed bilateral MT of the MCA and effective recanalization.Case presentationThe patient is a 73-year-old man who complained of a sudden adverse influence on speech and an inability to move his left limb for 2 h. He had a history of paroxysmal atrial fibrillation, but had never used any anticoagulants before. Head and neck computed tomography angiography (CTA) showed embolism in the right M1 MCA. During intravenous alteplase thrombolytic therapy, the patient suddenly became unconscious. Cerebral angiography showed occlusion of the M1 segment of the bilateral MCA in the patients. MT of the bilateral MCA was performed using a combination of a stent retriever and an aspiration catheter with mTici 3 revascularization. On the second day, the patient became conscious, although he had remaining symptoms of speech insufficiency and weakness of the left limb. The mRS score was 2 90 days after the operation.ConclusionsAcute bilateral occlusion of the M1 segment of the MCA is extremely rare and is accompanied by high morbidity and high mortality. Intravenous alteplase thrombolysis can increase the risk of atrial thrombus shedding in patients with atrial fibrillation, so patients with acute bilateral MCA occlusion in the M1 segment chose direct MT or bridging therapy, which remains controversial, and the sequence of MT remains to be discussed. Nevertheless, early endovascular treatment can decrease the morbidity and mortality of such patients.

Background and PurposeThe method of mechanical thrombectomy (MT) is related to vascular anatomy and stroke etiology. Meniscus sign and thrombus permeability as imaging markers may be instructive for the selection of MT. This study aims to clarify the relationship among meniscus sign, thrombus permeability, and choice of MT in patients with acute middle cerebral artery occlusion.Materials and MethodsA total of 111 patients with acute middle cerebral artery occlusion (MCAO) who underwent MT were retrospectively analyzed. Clot meniscus sign was defined as the appearance of meniscoid/edge-like or single- or double-wall contrast channels besides or around insular blood clots. The radiographic, clinical, and surgical data of patients with MCAO with or without meniscus sign were compared.ResultsThe meniscus sign positive group (n = 26) has higher thrombus permeability (HUs) (26.92 ± 9.69 vs. 22.84 ± 7.88, p = 0.031) than those without it. Shorter puncture-to-recanalization (P2R) time (65.5 vs. 88, p = 0.012), higher complete recanalization rate (85.71 vs. 33.33%, p < 0.01), and better clinical outcome (p < 0.01) were obtained by selecting contact aspiration (CA) over stent retriever (SR) in patients with positive meniscus sign. In patients with negative meniscus sign, there was no significant difference in clinical outcome after receiving CA or SR.ConclusionPatients with MCAO with positive meniscus sign have higher thrombus permeability and are more suitable for CA to acquire better clinical outcomes.

Vascular territory mapping (VTM) software estimates which intracerebral vessel provides predominant arterial flow to a brain voxel. The presence of antegrade flow in the setting of acute middle cerebral artery (MCA) occlusion is associated with improved outcomes. We identify whether VTM software is a determinant of antegrade flow in patients with proximal MCA occlusion. Consecutive patients with the first branch of MCA (M1) occlusion were analyzed from the International Stroke Perfusion Imaging Registry with their computed tomography perfusion reprocessed through VTM software. Authors reviewed dynamic 4-dimensional computed tomography angiography for the presence of an acute M1 thrombus and also for the presence of residual antegrade flow. The VTM software assigned regions of the brain to an estimated feeding vessel (anterior cerebral artery, MCA, and posterior cerebral artery). A binomial logistic regression was performed to determine the effects of VTM, ischemic core (cerebral blood flow <30), and perfusion lesion (delay time >3) on the likelihood that patients had the presence of any antegrade flow in the MCA territory. A secondary analysis was performed to assess the relationship between imaging variables and 3-month modified Rankin Scale outcomes. The final data set included 130 patients with M1 occlusion. The median age of participants was 74 years (interquartile range, 62-81) with an onset-to-scan time of 2.1 hours (interquartile range, 1.4-3.8) and a National Institutes of Health Stroke Scale score of 15 (interquartile range, 12-20). Eighteen patients were identified with antegrade flow on 4-dimensional digital subtraction angiography. Patients with antegrade flow had significantly larger VTM volume normal side MCA, 101 (72-180) mL, compared with those with complete occlusion, 41 (21-71) mL. VTM volume normal side MCA volume significantly predicted antegrade flow and outcome, and 1 mL VTM volume normal side MCA volume increased odds of antegrade flow by 1.024 (95% CI, 1.013-1.036). Ischemic core and the perfusion lesion volumes did not predict antegrade flow. VTM software was more effective than traditional perfusion parameters in the detection of antegrade flow. The results demonstrate a potential clinical utility for VTM; however, larger cohorts will be required to detect whether VTM can predict clinical outcome after reperfusion treatment.

Background: Good collaterals in acute ischemic stroke (AIS) correlate with smaller infarct size, improved outcome, and better recanalization rates after revascularisation treatments. Given that the variables determining collateral circulation are poorly understood, we aimed to identify predictors of good collaterals in a large series of AIS with middle cerebral artery (MCA) occlusion. Methods: In the Acute STroke Registry and Analysis of Lausanne (ASTRAL) from 2003 to 2016, we identified all AIS with MCA occlusion (M1 or proximal M2) on CT angiography (CTA) performed within 24 hours. Collaterals were graded from 0 (absent) to 3 (100% or more) and classified as good (grades 2 and 3) or poor. We correlated collateral status with various clinical, metabolic and radiological variables in a univariate, then multivariate regression analyses (MVA). Results: Of the 2’027 patients with AIS involving the MCA and good quality CTA during the study period, 857 met the inclusion criteria. Median age was 72.3±20.5 years, 48.4% were females, and median admission NIHSS was 16±9. Younger age (OR=0.99, confidence interval (CI) 0.98-0.99) and lower NIHSS on admission (OR=0.92, CI=0.90-0.94) were significantly associated with good collaterals. Hyperglycemia (OR=0.94, CI=0.88-0.99) and higher creatininemia (OR=0.99, CI=0.99-1) correlated with poor collaterals. The distribution of vascular risk factors was similar. Radiologically, good collateral status was predicted by higher ASPECTS score (OR=1.31, CI=1.24-1.40), absence of a hyperdense MCA sign (OR=0.60, CI=0.46-0.79), lower clot burden (OR=1.18, CI=1.12-1.24) and absence of proximal intracranial arterial pathology (OR=0.44, CI=0.33-0.58). MVA results will be presented. Conclusion: Good collaterals are associated with lower age and lower NIHSS, whereas high blood glucose and creatinine values predicted poor collaterals. On neuroimaging, minor early ischemic changes, lower clot burden and distal site of vascular occlusion correlated with good collaterals. These data may predict stroke outcome in certain patients, explain futile recanalisation, and help select patients for late or aggressive recanalisation treatments independently of time windows.

Recanalization with the Wingspan stent, which can be deployed rapidly and safely, is an option for treating acute ischemic stroke when intravenous thrombolysis has failed or is contraindicated. This study was performed to evaluate feasibility, efficacy, and safety of recanalization for acute middle cerebral artery occlusion using the Wingspan stent. We collected 10 patients with acute MCA occlusion in whom recanalization was not achieved with a standard intravenous thrombolysis, or who were ineligible for intravenous thrombolysis, or who presented after 3 hours of symptom onset and in whom the stent placement could be completed within 8 hours from symptom onset. We analyzed angiographic and clinical results. Successful recanalization with the Wingspan stent was achieved in all patients. The mean NIHSS score on admission was 12.7 points (range 4-21). The occlusion sites were located in the 1st segment (n = 7; 2 left, 5 right) and 2nd segment (n = 3, all right) of the MCA. The mean time interval from stroke symptom onset to stent placement was 344.8 ± 76.3 minutes. No intracranial hemorrhage, vessel perforations, or dissections occurred in any patient. Nine patients improved on the NIHSS at 7 days. One patient did not have a change in the NIHSS score, even though the occluded artery was completely recanalized. At 7 days, the NIHSS score of all patients was 4.4 ± 4.7 (median 4, range 0-13). At discharge, an mRS of ≤ 3 was achieved in all patients and an mRS of ≤ 2 was achieved in 7 patients (70%). This small case series demonstrates the feasibility of using the Wingspan stent safely and effectively for MCA occlusions when standard treatments are ineffective or not available.

To determine the efficacy of mechanical thrombectomy combined with prolonged mild hypothermia compared with conventional treatment in managing acute middle cerebral artery occlusion, and to explore whether extending the duration of hypothermia can improve neurological function. From 2018 to June 2023, a retrospective analysis was conducted on 45 patients with acute middle cerebral artery occlusion treated at the NICU of Suzhou Kowloon Hospital, affiliated with Shanghai Jiao Tong University School of Medicine. After thrombectomy, patients were admitted to the neurological intensive care unit (NICU) for targeted temperature management. Patients were divided into two groups: the mild hypothermia group (34.5-35.9°C) receiving 5-7 days of treatment, and the normothermia group (control group) whose body temperature was kept between 36 and 37.5°C using pharmacological and physical cooling methods. Baseline characteristics and temperature changes were compared between the two groups of patients. The primary outcome was the modified Rankin Scale (mRS) score at 3 month after surgery, and the secondary outcomes were related complications and mortality rate. Prognostic risk factors were investigated using both univariate and multivariate logistic regression analyses. Among 45 patients, 21 underwent prolonged mild hypothermia, and 24 received normothermia, with no significant differences in baseline characteristics between the two groups. The duration of mild hypothermia ranged from 5 to 7 days. The incidence of chills (33.3% vs. 8.3%, p = 0.031) and constipation (57.1% vs. 20.8%, p = 0.028) was significantly higher in the mild hypothermia group compared with the control group. There was no significant difference in mortality rates between the mild hypothermia and the control group (4.76% vs. 8.33%, p = 1.000, OR = 1.75, 95% CI, 0.171-17.949). At 3 month, there was no significant difference in the modified mRS (0-3) score between the mild hypothermia and control groups (52.4% vs. 25%, p = 0.114, OR = 0.477, 95% CI, 0.214-1.066). Infarct core volume was an independent risk factor for adverse neurological outcomes. Prolonged mild hypothermia following mechanical thrombectomy had no severe complications and shows a trend to improve the prognosis of neurological function. The Infarct core volume on CTP was an independent risk factor for predicting neurological function.

Asymmetrical prominent veins (APVs) can help predict perfusion deficits and collateral circulation in large vessel occlusion acute ischemic stroke. Therefore, this study aimed to investigate the predictive value of APVs for parenchymal hematoma (PH) following mechanical thrombectomy (MT). This study retrospectively included consecutive patients with ischemic stroke due to middle cerebral artery occlusion who underwent MT. APVs were quantified using the APVs-Alberta Stroke Program Early Computed Tomography Score (ASPECTS) system, and we recorded the length and diameter of the susceptibility vessel sign (SVS), the number of cerebral microbleeds (CMBs), post-MT blood flow grading, and whether PH occurred within 24 hours. Logistic regression was performed to identify risk factors for PH. A total of 89 patients with acute middle cerebral artery occlusion were included. APVs-ASPECTS was identified as an independent predictor of PH [odds ratio (OR) =0.604 (0.392, 0.930); P=0.022], and the length of SVS [OR =0.882 (0.792, 0.981); P=0.021] was an independent predictor of successful recanalization [modified Thrombolysis In Cerebral Ischemia (mTICI) 2b/3] after MT. There was no significant difference in the number of CMBs between the PH (+) and PH (-) groups (P=0.341). In patients with acute middle cerebral artery occlusion who underwent MT, APVs-ASPECTS may be associated with the risk of PH.