Intracranial arteriovenous malformations may receive part or all of their blood supply from meningeal branches of the external carotid, internal carotid, or vertebral arteries, although previous authors(2–5,8, 10, 15–17,20,21,24)have suggested that such a meningeal contribution is infrequent. The malformations may be classified on the basis of their arterial supply as pure pial, mixed pial and dural, and pure dural. Those that are entirely pial in location are supplied solely by cerebral or cerebellar arteries. Mixed pial and dural malformations receive their blood supply not only from cerebral or cerebellar arteries but also from meningeal vessels. Pure dural malformations are limited to the dura and thus receive only meningeal arterial contribution. The purpose of this study was to evaluate the location of intracranial arteriovenous malformations based on the presence or absence of a dural blood supply. Method Arteriograms of patients with intra-cranial arteriovenous malformations examined at the Univer...

Involvement of Dural Arteries in Intracranial Arteriovenous Malformations

THE NIH REGISTRY ON USE OF THE WINGSPAN STENT FOR SYMPTOMATIC 70 – 99% INTRACRANIAL ARTERIAL STENOSIS To the Editor: We read with interest that a relatively high rate of in-stent restenosis (ISR) (25%) was revealed in the NIH Wingspan registry.1 This figure may not be an overestimate. In our cohort of 40 patients with self-expandable stenting for symptomatic intracranial stenosis, 19 had repeat digital subtraction angiography (DSA) in 12 months. ISR ( 50% stenosis) developed in 5 patients (26.3%), which was apparently independent of cardiovascular risk factor control. ISR may be more frequent in daily practice than the rate in the Wingspan phase I study.2 Although most patients with ISR remain asymptomatic, neo-intimal hyperplasia in intracranial vasculature may not be as benign as the authors suggested.1 In a coronary model, ISR may cause branch occlusion and symptom recurrence.3 In cerebral circulation, neo-intimal proliferation may similarly occlude perforators arising from middle cerebral artery (MCA) or basilar artery (BA) and cause infarction in the perforator territory where collateral is minimal. Furthermore, given the small luminal diameter of intracranial vessels, ISR predisposes to perfusion failure apart from thromboembolic risk. ISR could be an important factor governing the longterm outcome after intracranial stenting. A randomized trial is warranted to investigate the efficacy of stenting in symptomatic intracranial stenosis, and it is encouraging to know that one is currently planned in the United States.1 In a country where intracranial stenosis is particularly prevalent, we have been conducting a pilot, randomized study comparing optimal medical treatment vs early adjunctive self-expandable stenting in patients with high risk of recurrence (i.e., recent cerebral ischemic event attributed to a high-grade [ 70%] intracranial stenosis). Some issues encountered during the planning of our study may warrant discussion. First, we randomized patients based on DSA rather than CT angiography (CTA). CTA is invaluable for screening, but is insufficient to accurately quantify the severity of stenosis. In a few patients who had initially consented to the study, subtle vascular anomalies adjacent to the stenosis (like fenestrated MCA or BA) could only be revealed in threedimensional reconstruction of DSA but not in CTA. Catastrophic complications may have occurred if CTA alone was relied upon. Secondly, although double antiplatelet regimen has not been shown to be more effective than single antiplatelet treatment in symptomatic intracranial stenosis, combination therapy has been shown to decrease microembolic signal in symptomatic carotid stenosis.4 To avoid this potential confounder, patients in both stenting and medical groups are offered dual antiplatelets.

THE NIH REGISTRY ON USE OF THE WINGSPAN STENT FOR SYMPTOMATIC 70-99% INTRACRANIAL ARTERIAL STENOSIS. Authors' reply

Background COVID-19 infection has been known to predispose patients to both arterial and venous thromboembolic events such as deep venous thrombosis, pulmonary embolism, myocardial infarction, and stroke. A few reports from the literature suggest that Cerebral Venous Sinus Thrombosis (CVSTs) may be a direct complication of COVID-19. Objective To review the clinical and radiological presentation of COVID-19 positive patients diagnosed with CVST. Methods This was a multicenter, cross-sectional, retrospective study of patients diagnosed with CVST and COVID-19 reviewed from March 1, 2020 to November 8, 2020. We evaluated their clinical presentations, risk factors, clinical management, and outcome. We reviewed all published cases of CVST in patients with COVID-19 infection from January 1, 2020 to November 13, 2020. Results There were 8 patients diagnosed with CVST and COVID-19 during the study period at 7 out of 31 participating centers. Patients in our case series were mostly female (7/8, 87.5%). Most patients presented with non-specific symptoms such as headache (50%), fever (50%), and gastrointestinal symptoms (75%). Several patients presented with focal neurologic deficits (2/8, 25%) or decreased consciousness (2/8, 25%). D-dimer and inflammatory biomarkers were significantly elevated relative to reference ranges in patients with available laboratory data. The superior sagittal and transverse sinuses were the most common sites for acute CVST formation (6/8, 75%). Median time to onset of focal neurologic deficit from initial COVID-19 diagnosis was 3 days (interquartile range 0.75–3 days). Median time from onset of COVID-19 symptoms to CVST radiologic diagnosis was 11 days (interquartile range 6–16.75 days). Mortality was low in this cohort (1/8 or 12.5%). Conclusions Clinicians should consider the risk of acute CVST in patients positive for COVID-19, especially if neurological symptoms develop.

Cerebral Venous Sinus Thrombosis in COVID-19 Patients: A Multicenter Study and Review of Literature.

There is growing evidence for endovascular thrombectomy (EVT) in patients with large ischemic core infarct and large vessel occlusion. The objective of this study was to compare the efficacy and safety of EVT versus medical management (MM) via a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs).We searched the PubMed, Embase, Cochrane Library, and Web of Science databases to obtain articles related to mechanical thrombectomy for large ischemic core from inception until February 10, 2023. The primary outcome was independent ambulation (modified Rankin Scale [mRS] 0-3). Effect sizes were computed as risk ratio (RR) with random-effect or fixed-effect models. The quality of articles was evaluated through the Cochrane risk assessment tool and Newcastle-Ottawa scale. This study was registered in PROSPERO (CRD42023396232).A total of 5395 articles were obtained through the search and articles that did not meet the inclusion criteria were excluded by review of the title, abstract, and full text. Finally, 3 RCTs and 10 cohort studies met the inclusion criteria. The RCT analysis showed that EVT improved the 90-day functional outcomes of patients with large ischemic core with high-quality evidence, including independent ambulation (mRS 0-3: RR 1.78, 95% CI 1.28-2.48, P < 0.001) and functional independence (mRS 0-2: RR 2.59, 95% CI 1.89-3.57, P < 0.001), but without significantly increasing the risk of symptomatic intracranial hemorrhage (sICH: RR 1.83, 95% CI: 0.95-3.55, P = 0.07) or early mortality (RR 0.95, 95% CI 0.78-1.16, P = 0.61). Analysis of the cohort studies showed that EVT improved functional outcomes of patients without an increase in the incidence in sICH.This systematic review and meta-analysis indicates that in patients with large vessel occlusion stroke with a large ischemic core, EVT was associated with improved functional outcomes over medical management without increasing sICH risk. Results of ongoing RCTs may provide further insight in this patient population. 

Mechanical Thrombectomy for Large Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study's objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines. METHODS: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation. FINDINGS: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p<0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p<0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile. INTERPRETATION: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction.

/pdf/decline-in-subarachnoid-haemorrhage-volumes-associated-with-2rt1ooysbb.pdf

Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic.

Intracranial endovascular interventions provide effective and minimally invasive treatment of a broad spectrum of diseases. This area of expertise has continued to gain both wider application and greater depth as new and better techniques are developed and as landmark clinical studies are performed to guide their use. Some of the greatest advances since the last American Heart Association scientific statement on this topic have been made in the treatment of ischemic stroke from large intracranial vessel occlusion, with more effective devices and large randomized clinical trials showing striking therapeutic benefit. The treatment of cerebral aneurysms has also seen substantial evolution, increasing the number of aneurysms that can be treated successfully with minimally invasive therapy. Endovascular therapies for such other diseases as arteriovenous malformations, dural arteriovenous fistulas, idiopathic intracranial hypertension, venous thrombosis, and neoplasms continue to improve. The purpose of the present document is to review current information on the efficacy and safety of procedures used for intracranial endovascular interventional treatment of cerebrovascular diseases and to summarize key aspects of best practice.

Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association.

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Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association.