Reocclusion after successful endovascular treatment in acute ischemic stroke: systematic review and meta-analysis.

BACKGROUND: Endovascular treatment (EVT) is the standard of care for selected patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). OBJECTIVE: To systematically review the available data on: (1) incidence, predictors, and outcomes of patients with reocclusion after successful EVT for AIS and, (2) the characteristics, complications, and outcomes of patients with reocclusion treated with repeated EVT (rEVT) within 30 days of the first procedure. METHODS: PubMed was searched (between January 2012 and April 2021) to identify studies reporting reocclusion following successful EVT (Thrombolysis in Cerebral Infarction ≥2b) in patients with AIS due to LVO. Pooled incidence of reocclusion per 100 patients with successful recanalization following EVT was calculated using a random-effects model with Freeman-Tukey double arcsine transformation. Extracted incidences of reocclusion according to etiology and use of intravenous thrombolysis were pooled using random-effects meta-analytic models. RESULTS: A total of 840 studies was identified and seven studies qualified for the quantitative analysis, which described 91 same-vessel reocclusions occurring within the first 7 days after treatment among 2067 patients (4.9%; 95% CI 3% to 7%, I2=70.2%). Large vessel atherosclerosis was associated with an increased risk of reocclusion (OR=3.44, 95% CI 1.12 to 10.61, I2=50%). We identified 90 patients treated with rEVT for recurrent LVO, described in five studies. The rates of procedural complications, mortality, and unfavorable functional outcome at 3 months were 18.0%, 18.9%, and 60.3%, respectively. CONCLUSION: In cohorts of patients with AIS due to LVO, 5% of patients experienced reocclusion within 7 days after successful EVT. Repeated EVT can be a safe and effective treatment for selected patients with reocclusion.

Non-stenosing carotid artery plaques in embolic stroke of undetermined source: a retrospective analysis.

BACKGROUND: We aim to identify the association between high-risk carotid plaques and their laterality to stroke in ESUS patient population. We also discuss recurrent stroke events and their laterality to the index stroke. METHODS: This was a retrospective study. We reviewed data for patients with ESUS between June 20, 2016, and June 20, 2021. Using computed tomography angiography, we analyzed plaque features that are associated with ESUS, and then, we identified the recurrent stroke events and characterized lateralization to the index stroke. RESULTS: Out of 1779 patients with cryptogenic ischemic stroke, we included 152 patients who met the criteria for ESUS. High-risk plaque features were found more often ipsilateral to the stroke side when compared contralaterally: plaque ulceration (19.08% vs 5.26%, p < .0001), plaque thickness > 3 mm (19.08% vs 7.24%, p = 0.001), and plaque length > 1 cm (13.16% vs 5.92%, p = 0.0218). There was also a significant difference in plaque component in which both components (soft and calcified) and only soft plaques were more prevalent ipsilaterally (42.76% vs 23.68% and 17.76% vs 9.21%, respectively, p < .0001). Of the 152 patients, 17 patients were found to have a recurrent stroke event, and 47% (n = 8) had an ipsilateral stroke to the index event. Moreover, stroke was bilateral in 41% of the patients (n = 7), and contralateral in 12% (n = 2). CONCLUSION: High-risk plaque features studied here were more prevalent ipsilaterally to the stroke side in ESUS than contralaterally. Multicenter studies are needed to form precise prediction models and scoring systems to help guide treatment, i.e., choice of medical therapy and/or revascularization.

The role of non-stenosing carotid artery plaques in embolic stroke of undetermined source, is it a silent offender? A review of literature.

PURPOSE: Atherosclerotic cervical internal carotid artery disease is one of the major causes of ischemic stroke and transient ischemic attacks. The risk of stroke from mild to moderate stenoses (i.e. <50% stenosis) might be underestimated. There is increasing evidence that plaque morphological features reflect plaque instability that may harbor high risk for embolization. In this narrative review, we will review the literature on plaque features that predict vulnerability beyond the degree of stenosis, discuss the clinical association with stroke, and evaluate the evidence that these lesions serve as a source for embolic stroke of unknown source (ESUS). METHODS: We performed a literature search using PubMed, EMBASE, and Web of Science. The terms "embolic stroke of undetermined source" and "plaque morphology" were used either alone or in combination with "non-flow limiting stenosis," "non-stenosing plaques," "high-risk plaque features" or "internal carotid artery plaque." Data on plaque morphology and ESUS were mainly taken from review articles, observational studies including retrospective cohort and cross-sectional studies, meta-analyses, and systematic reviews. CONCLUSION: Nonstenosing carotid artery plaques with high-risk features carry a remarkable risk for stroke occurrence and randomized clinical trials are warranted for further evaluation of using carotid artery stenting or carotid endarterectomy to mitigate the risk of stroke.

Repeated Mechanical Endovascular Thrombectomy for Recurrent Large Vessel Occlusion: A Multicenter Experience.

BACKGROUND AND PURPOSE: Mechanical thrombectomy (MT) is now the standard of care for large vessel occlusion (LVO) stroke. However, little is known about the frequency and outcomes of repeat MT (rMT) for patients with recurrent LVO. METHODS: This is a retrospective multicenter cohort of patients who underwent rMT at 6 tertiary institutions in the United States between March 2016 and March 2020. Procedural, imaging, and outcome data were evaluated. Outcome at discharge was evaluated using the modified Rankin Scale. RESULTS: Of 3059 patients treated with MT during the study period, 56 (1.8%) underwent at least 1 rMT. Fifty-four (96%) patients were analyzed; median age was 64 years. The median time interval between index MT and rMT was 2 days; 35 of 54 patients (65%) experienced recurrent LVO during the index hospitalization. The mechanism of stroke was cardioembolism in 30 patients (56%), intracranial atherosclerosis in 4 patients (7%), extracranial atherosclerosis in 2 patients (4%), and other causes in 18 patients (33%). A final TICI recanalization score of 2b or 3 was achieved in all 54 patients during index MT (100%) and in 51 of 54 patients (94%) during rMT. Thirty-two of 54 patients (59%) experienced recurrent LVO of a previously treated artery, mostly the pretreated left MCA (23 patients, 73%). Fifty of the 54 patients (93%) had a documented discharge modified Rankin Scale after rMT: 15 (30%) had minimal or no disability (modified Rankin Scale score ≤2), 25 (50%) had moderate to severe disability (modified Rankin Scale score 3-5), and 10 (20%) died. CONCLUSIONS: Almost 2% of patients treated with MT experience recurrent LVO, usually of a previously treated artery during the same hospitalization. Repeat MT seems to be safe and effective for attaining vessel recanalization, and good outcome can be expected in 30% of patients.

Cerebral endothelial cell-derived small extracellular vesicles enhance neurovascular function and neurological recovery in rat acute ischemic stroke models of mechanical thrombectomy and embolic stroke treatment with tPA.

Treatment of patients with cerebral large vessel occlusion with thrombectomy and tissue plasminogen activator (tPA) leads to incomplete reperfusion. Using rat models of embolic and transient middle cerebral artery occlusion (eMCAO and tMCAO), we investigated the effect on stroke outcomes of small extracellular vesicles (sEVs) derived from rat cerebral endothelial cells (CEC-sEVs) in combination with tPA (CEC-sEVs/tPA) as a treatment of eMCAO and tMCAO in rat. The effect of sEVs derived from clots acquired from patients who had undergone mechanical thrombectomy on healthy human CEC permeability was also evaluated. CEC-sEVs/tPA administered 4 h after eMCAO reduced infarct volume by ∼36%, increased recanalization of the occluded MCA, enhanced cerebral blood flow (CBF), and reduced blood-brain barrier (BBB) leakage. Treatment with CEC-sEVs given upon reperfusion after 2 h tMCAO significantly reduced infarct volume by ∼43%, and neurological outcomes were improved in both CEC-sEVs treated models. CEC-sEVs/tPA reduced a network of microRNAs (miRs) and proteins that mediate thrombosis, coagulation, and inflammation. Patient-clot derived sEVs increased CEC permeability, which was reduced by CEC-sEVs. CEC-sEV mediated suppression of a network of pro-thrombotic, -coagulant, and -inflammatory miRs and proteins likely contribute to therapeutic effects. Thus, CEC-sEVs have a therapeutic effect on acute ischemic stroke by reducing neurovascular damage.

Quantification of pial collateral pressure in acute large vessel occlusion stroke: basic concept with patient outcomes.

PURPOSE: Pial collateral perfusion to the ischemic penumbra plays a critical role in determining patient outcomes in acute stroke. We aimed to assess the validity and reliability of an intra-procedural technique for measuring and quantifying the pial collateral pressure (QPCP) to ischemic brain tissue during acute stroke secondary to LVO. QPCP measurements were correlated with standard computed tomography angiography (CTA) and digital subtraction angiography imaging assessments of pial collateral perfusion and outcomes after mechanical endovascular revascularization (MER). METHODS: This prospective cohort study included 60 consecutive patients with middle cerebral artery (MCA)-M1 and proximal M2 occlusions. QPCP measurements were obtained during MER. The validity of QPCP measurements was evaluated using four widely accepted collateral grading scales. QPCP measurements were also analyzed as a predictor of patient outcomes utilizing National Institute of Health Stroke Scale reduction at 24 h and modified Rankin Scale (mRS) scores at 30 days. RESULTS: QPCP measurements and QPCP ratio (QPCP/systemic mean arterial blood pressure) showed a statistically significant association with single-phase pretreatment CTA Maas and American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology binary grading scales. Patient outcomes demonstrated for every 10-unit increase in QPCP, the odds of mRS 0-2 at 30 days increased by 76% (p = 0.019). CONCLUSION: QPCP measurements related best with the pretreatment CTA Maas collateral grading scale but were more strongly associated with patient outcomes than any of the four widely accepted collateral grading scales. Greater QPCP was significantly associated with better overall patient outcomes as defined by mRS at 30 days.

Challenges of acute phase neuroimaging in VA-ECMO, pitfalls and alternative imaging options.

Large vessel occlusion in patients on ECMO is challenging to appreciate clinically secondary to sedation or induced paralysis, thus placing more emphasis on neurovascular imaging. However, emergent CTA and CTP are both inaccurate and unreliable in ECMO patients due to altered circuitry and interference with normal physiologic hemodynamics. In this review, the utility of DSA is discussed in evaluating the altered hemodynamics of VA-ECMO circuits and patency of major vasculature. In addition, the potential use of TCD in ECMO patients is discussed.

Imaging Findings in Non-Neoplastic Sinonasal Disease: Review of Imaging Features With Endoscopic Correlates.

Non-neoplastic sinonasal disease is common and imaging often plays an important role in establishing the proper diagnosis, guiding clinical management, and evaluating for complications. Both computed tomography and magnetic resonance imaging are commonly employed in the imaging evaluation and it is important to understand the imaging characteristics of the unique types of pathology affecting the sinonasal cavities. This article reviews a variety of infectious, inflammatory, and other non-neoplastic sinonasal pathologies, highlighting imaging features that aid in their differentiation.

M2 segment thrombectomy is not associated with increased complication risk compared to M1 segment: A meta-analysis of recent literature.

INTRODUCTION: Recent clinical comparisons of M1 and M2 segment endovascular thrombectomy have reached incongruous results in rates of complication and functional outcomes. This study aims to clarify the controversy surrounding this rapidly advancing technique through literature review and meta-analysis. METHODS: A Pubmed search was performed (January 2015-September 2019) using the following keywords: "M2 AND ("stroke" OR "occlusion") AND ("thrombectomy" OR "endovascular")". Safety and clinical outcomes were compared between segments via weighted Student's t-test, Chi-square and odds ratio while study heterogeneity was analyzed using Cochran Q and I2 tests. RESULTS: Pubmed identified 208 articles and eleven studies were included after full-text analysis, comprising 2,548 M1 and 758 M2 mechanical thrombectomy segment cases. Baseline National Institutes of Health Stroke Scale scores were comparatively lower in patients experiencing an M2 occlusion (16 ± 1.25 vs 13.6 ± 0.96, p < 0.01). Patients who underwent M2 mechanical thrombectomy were more likely to experience both good clinical outcomes (modified Rankin Scale 0-2) (48.6% vs 43.5% respectively, OR 1.24; CI 1.05-1.47, p = 0.01) and excellent clinical outcomes (modified Rankin Scale 0-1) (34.7% vs. 26.5%%, OR 1.6; CI 1.28-1.99, p < 0.01) at 90 days compared to M1 mechanical thrombectomy. Neither recanalization rates (75.3% vs 72.8%, OR 0.92, CI 0.75-1.13, p = 0.44) nor symptomatic intracranial hemorrhage rates (5.6% vs 4.9%, OR 0.92; CI 0.61-1.39, p= 0.7) were significantly different between M1 and M2 cohorts. Mortality was less frequent in the M2 cohort compared to M1 (16.3% vs 20.7%, OR 0.73; CI 0.57-0.94, p = 0.01). M1 and M2 cohorts did not differ in symptom onset-to-puncture (238.1 ± 46.7 vs 239.8 ± 43.9 min respectively, p=0.488) nor symptom onset-to recanalization times (318.7 ± 46.6 vs 317.7 ± 71.1 min respectively, p = 0.772), though mean operative duration was shorter in the M2 cohort (61.8 ± 25.5 vs 54.6 ± 24 min, p < 0.01). CONCLUSIONS: Patients who underwent M2 mechanical thrombectomy had a higher prevalence of good and excellent clinical outcomes compared to the M1 mechanical thrombectomy cohorts. Additionally, our data suggest lower mortality rates in the M2 cohort and symptomatic intracranial hemorrhage rates that are similar to the M1 cohort. Therefore, M2 segment thrombectomy likely does not pose a significantly elevated operative risk and may have a positive impact on patient outcomes.

CTA-for-All: Impact of Emergency Computed Tomographic Angiography for All Patients With Stroke Presenting Within 24 Hours of Onset.

Background and Purpose- We sought to evaluate the impact of a Computed Tomographic Angiography (CTA) for All emergency stroke imaging protocol on outcome after large vessel occlusion (LVO). Methods- On July 1, 2017, the Henry Ford Health System implemented the policy of performing CTA and noncontrast computed tomography together as an initial imaging study for all patients with acute ischemic stroke (AIS) presenting within 24 hours of last known well, regardless of baseline National Institutes of Health Stroke Scale score. Previously, CTA was reserved for patients presenting within 6 hours with a National Institutes of Health Stroke Scale score ≥6. We compared treatment processes and outcomes between patients with AIS admitted 1 year before (n=388) and after (n=515) protocol implementation. Results- After protocol implementation, more AIS patients underwent CTA (91% versus 61%; P<0.001) and had CTA performed at the same time as the initial noncontrast computed tomography scan (78% versus 35%; P<0.001). Median time from emergency department arrival to CTA was also shorter (29 [interquartile range, 16-53] versus 43 [interquartile range, 29-112] minutes; P<0.001), more cases of LVO were detected (166 versus 96; 32% versus 25% of all AIS; P=0.014), and more mechanical thrombectomy procedures were performed (108 versus 68; 21% versus 18% of all AIS; P=0.196). Among LVO patients who presented within 6 hours of last known well, median time from last known well to mechanical thrombectomy was shorter (3.5 [interquartile range, 2.8-4.8] versus 4.1 [interquartile range, 3.3-5.6] hours; P=0.038), and more patients were discharged with a favorable outcome (Glasgow Outcome Scale 4-5, 53% versus 37%; P=0.029). The odds of having a favorable outcome after protocol implementation was not significant (odds ratio, 1.84 [95% CI, 0.98-3.45]; P=0.059) after controlling for age and baseline National Institutes of Health Stroke Scale score. Conclusions- Performing CTA and noncontrast computed tomography together as an initial assessment for all AIS patients presenting within 24 hours of last known well improved LVO detection, increased the mechanical thrombectomy treatment population, hastened intervention, and was associated with a trend toward improved outcome among LVO patients presenting within 6 hours of symptom onset.

Anterior Cerebral Artery: Variant Anatomy and Pathology.

The anterior cerebral artery (ACA) contains anatomical variants that are closely related to its embryology and development. In this study, the authors reviewed the most commonly encountered variants of the ACA and anterior communicating artery. They also reviewed the embryological origins of these variants as well as a variety of associated pathologies. Several variants are described and highlighted with illustrations including: (1) the aberrant origin of the ACA from the internal carotid artery and its developmental association with the ophthalmic artery; (2) the persistent olfactory artery; (3) the azygous ACA; (4) the triplicated ACA; and (5) multiple anterior communicating arteries. The formation of aneurysms is associated with such variants, thus their knowledge and the embryology behind their development are crucial to prevent injury to the patient.

Cord Topographical Anatomy and its Role in Evaluating Intramedullary Lesions.

Intramedullary spinal lesions present a wide differential diagnosis including infectious, inflammatory, traumatic, ischemic, benign, or malignant neoplastic etiologies. Using knowledge of anatomy and physiology within the spinal cord, many similar appearing entities can be parsed into a prioritized differential. The purpose of this article is to review anatomy and pathophysiology of the spinal cord, with subsequent discussion of how this knowledge can be used to differentiate several similar appearing intramedullary pathologic processes. Discussion includes the pathophysiology, imaging findings, and clinical pearls of several intramural lesions including infarct, demyelinating lesions, traumatic injury, neoplasm, vascular malformation, and metabolic processes such as subacute combined degeneration.

Separate origins of the left internal and external carotid arteries from the aortic arch and cervical internal carotid artery aneurysm in a patient with Noonan syndrome.

Distinct origins of the external carotid artery and the internal carotid artery (ICA) from the aortic arch have been rarely described, and represent an aberrant development of the aortic arches during fetal life. This anatomical variation is usually discovered incidentally; infrequently, an aneurysm of the cervical ICA might accompany this rare configuration. We describe one such case in a patient with Noonan syndrome who presented with pulsatile neck mass. The diagnostic features and management of the aneurysm and a review of the literature are presented.

Separate origins of the left internal and external carotid arteries from the aortic arch and cervical internal carotid artery aneurysm in a patient with Noonan syndrome.

Distinct origins of the external carotid artery and the internal carotid artery (ICA) from the aortic arch have been rarely described, and represent an aberrant development of the aortic arches during fetal life. This anatomical variation is usually discovered incidentally; infrequently, an aneurysm of the cervical ICA might accompany this rare configuration. We describe one such case in a patient with Noonan syndrome who presented with pulsatile neck mass. The diagnostic features and management of the aneurysm and a review of the literature are presented.

MRI Pre- and Post-Embolization Enhancement Patterns Predict Surgical Outcomes in Intracranial Meningiomas.

PURPOSE: To evaluate the effects of preoperative embolization on overall surgical outcomes after meningioma resection and determine whether pre- and postembolization tumor enhancement patterns on magnetic resonance imaging (MRI) scans can be used to assess the efficacy of embolization. METHODS: We developed a prospective database of all patients who underwent surgical resection with or without preoperative embolization for extra-axial intracranial meningiomas from 2004 to 2010. Using specialized computer software, the total volume of enhancement was calculated in pre- and postembolization MRI scans to quantify the percentage of embolization, which was described as the embolization fraction (EF). RESULTS: A total of 89 patients underwent surgical resection. Fifty two patients underwent embolization prior to surgery. Tumor location significantly correlated with the decision to embolize preoperatively. Adequate embolization was achieved in 58% of patients. Forty four patients (84.6%) had a postsurgical Karnofsky performance score (KPS) of 80 or above, while 46 patients (88.4%) had a postsurgical Glascow Outcome Score (GOS) of 4 or 5. The mean EF was 25.03% with a median of 18.72%. A greater extent of embolization as quantified by EF led to decreased intraoperative blood loss (r = -.319, P = .022) and better postsurgical outcomes as defined by KPS (r = .279, P = .044). CONCLUSIONS: Pre- and postembolization tumor enhancement patterns on magnetic resonance imaging defined as EF correlate with improved surgical facilitation and postoperative functional outcomes in the management of intracranial meningioma.

Glioblastoma and intracranial aneurysms: Case report and review of literature.

BACKGROUND: There is a paucity of data on the association of glioblastoma multiforme (GBM) with intracranial aneurysms. It is an important clinical entity for physicians to be aware of and its presence illustrates several critical features of the pathophysiology of malignant glioma. In this article we present a case of a middle cerebral artery (MCA) pseudoaneurysm that occurred in a patient with recurrent GBM as well discuss the current literature relating to this unique combination of pathologies. CASE DESCRIPTION: The authors present a case of a MCA pseudoaneurysm that developed in a patient with recurrent GBM and discuss the current literature. The authors identified 19 reports describing 23 patients harboring both GBM and an intracranial aneurysm. CONCLUSION: Several theories stand to explain the coincidental occurrence of intracranial aneurysms and GBM. The treating physician should be aware of this association when patients with intraaxial tumors present with unusual manifestation such as an intratumoral hemorrhage or angiogram negative subarachnoid hemorrhage. No guidelines exist to assist in the management of such patients; therefore, authors have attempted to address this issue using a classification and treatment algorithm.

Desmoplastic infantile ganglioglioma with associated giant aneurysm­case report.

Desmoplastic infantile ganglioglioma (DIG) and supratentorial giant cerebral aneurysm are each extremely rare entities in infants. Here, we present the case of an 8-day old boy who had both of these conditions concurrently. To our knowledge, there is no previous case reported of a patient with coexisting DIG and giant aneurysm.

Spontaneous resolution of a flow-related ophthalmic-segment aneurysm after treatment of anterior cranial fossa dural arteriovenous fistula.

BACKGROUND: The natural history of proximal, feeding-artery aneurysms after successful obliteration of high-grade, anterior cranial fossa dural arteriovenous fistulas (dAVFs) has not been well documented. CASE DESCRIPTION: A 52-year-old Caucasian male presented with an unruptured anterior cranial fossa (dAVF) and an associated aneurysm. Cerebral angiography revealed a large, contralateral, carotid-ophthalmic segment aneurysm, enlarged feeding ophthalmic arteries, as well as cortical venous drainage. Successful surgical obliteration of the dAVF was undertaken to eliminate the risk of hemorrhage. CONCLUSION: The carotid-ophthalmic aneurysm regressed significantly after surgical obliteration of the dAVF and a follow-up, planned coiling procedure to address the carotid-ophthalmic aneurysm was abandoned. This represents the first reported case of a near complete, spontaneous resolution of an unruptured carotid-ophthalmic aneurysm associated with a high-grade anterior cranial fossa dAVF.