Endovascular Therapy vs Medical Management for Patients With Acute Stroke With Medium Vessel Occlusion in the Anterior Circulation

Importance Randomized clinical trials have shown the efficacy of endovascular therapy (EVT) for acute large vessel occlusion strokes. The benefit of EVT in acute stroke with distal, medium vessel occlusion (DMVO) remains unclear. Objective To examine the efficacy and safety outcomes associated with EVT in patients with primary DMVO stroke when compared with a control cohort treated with medical management (MM) alone. Design, Setting, and Participants This multicenter, retrospective cohort study pooled data from patients who had an acute stroke and a primary anterior circulation emergency DMVO, defined as any segment of the anterior cerebral artery (ACA) or distal middle cerebral artery, between January 1, 2015, and December 31, 2019. Those with a concomitant proximal occlusion were excluded. Outcomes were compared between the 2 treatment groups using propensity score methods. Data analysis was performed from March to June 2021. Exposures Patients were divided into EVT and MM groups. Main Outcomes and Measures Main efficacy outcomes included 3-month functional independence (modified Rankin Scale [mRS] scores, 0-2) and 3-month excellent outcome (mRS scores, 0-1). Safety outcomes included 3-month mortality and symptomatic intracranial hemorrhage. Results A total of 286 patients with DMVO were evaluated, including 156 treated with EVT (mean [SD] age, 66.7 [13.7] years; 90 men [57.6%]; median National Institute of Health Stroke Scale [NIHSS] score, 13.5 [IQR, 8.5-18.5]; intravenous tissue plasminogen activator [IV tPA] use, 75 [49.7%]; ACA involvement, 49 [31.4%]) and 130 treated with medical management (mean [SD] age, 69.8 [14.9] years; 62 men [47.7%]; median NIHSS score, 7.0 [IQR, 4.0-14.0], IV tPA use, 58 [44.6%]; ACA involvement, 31 [24.0%]). There was no difference in the unadjusted rate of 3-month functional independence in the EVT vs MM groups (151 [51.7%] vs 124 [50.0%]; P = .78), excellent outcome (151 [38.4%] vs 123 [31.7%]; P = .25), or mortality (139 [18.7%] vs 106 [11.3%]; P = .15). The rate of symptomatic intracranial hemorrhage was similar in the EVT vs MM groups (weighted: 4.0% vs 3.1%; P = .90). In inverse probability of treatment weighting propensity analyses, there was no significant difference between groups for functional independence (adjusted odds ratio [aOR], 1.36; 95% CI, 0.84-2.19; P = .20) or mortality (aOR, 1.24; 95% CI, 0.63-2.43; P = .53), whereas the EVT group had higher odds of an excellent outcome (mRS scores, 0-1) at 3 months (aOR, 1.71; 95% CI, 1.02-2.87; P = .04). Conclusions and Relevance The findings of this multicenter cohort study suggest that EVT may be considered for selected patients with ACA or distal middle cerebral artery strokes. Further larger randomized investigation regarding the risk-benefit ratio for DMVO treatment is indicated

Large Genomic Deletions in CACNA1A Cause Episodic Ataxia Type 2

Episodic ataxia (EA) syndromes are heritable diseases characterized by dramatic episodes of imbalance and incoordination. EA type 2 (EA2), the most common and the best characterized subtype, is caused by mostly nonsense, splice site, small indel, and sometimes missense mutations in CACNA1A. Direct sequencing of CACNA1A fails to identify mutations in some patients with EA2-like features, possibly due to incomplete interrogation of CACNA1A or defects in other EA genes not yet defined. Previous reports described genomic deletions between 4 and 40 kb in EA2. In 47 subjects with EA (26 with EA2-like features) who tested negative for mutations in the known EA genes, we used multiplex ligation-dependent probe amplification to analyze CACNA1A for exonic copy number variations. Breakpoints were further defined by long-range PCR. We identified distinct multi-exonic deletions in three probands with classic EA2-like features: episodes of prolonged vertigo and ataxia triggered by stress and fatigue, interictal nystagmus, with onset during infancy or early childhood. The breakpoints in all three probands are located in Alu sequences, indicating errors in homologous recombination of Alu sequences as the underlying mechanism. The smallest deletion spanned exons 39 and 40, while the largest deletion spanned 200 kb, missing all but the first three exons. One deletion involving exons 39 through 47 arose spontaneously. The search for mutations in CACNA1A appears most fruitful in EA patients with interictal nystagmus and onset early in life. The finding of large heterozygous deletions suggests haploinsufficiency as a possible pathomechanism of EA2

The Society of Vascular and Interventional Neurology (SVIN) Mechanical Thrombectomy Registry: Methods and Primary Results

Background A better understanding of real‐world practice patterns in the endovascular treatment for large vessel occlusion acute ischemic stroke is needed. Here, we report the methods and initial results of the Society of Vascular and Interventional Neurology (SVIN) Registry. Methods The SVIN Registry is an ongoing prospective, multicenter, observational registry capturing patients with large vessel occlusion acute ischemic stroke undergoing endovascular treatment since November 2018. Participating sites also contributed pre‐SVIN Registry data collected per institutional prospective registries, and these data were combined with the SVIN Registry in the SVIN Registry+ cohort. Results There were 2088 patients treated across 11 US centers included in the prospective SVIN Registry and 5372 in SVIN Registry+. In the SVIN Registry cohort, the median number of enrollments per institution was 160 [interquartile range 53–243]. Median age was 67 [58–79] years, 49% were women, median National Institutes of Health Stroke Scale 16 [10–21], Alberta stroke program early CT score 9 [7–10], and 20% had baseline modified Rankin scale (mRS)≥2. The median last‐known normal to puncture time was 7.7 [3.1–11.5] hours, and puncture‐to‐reperfusion was 33 [23–52] minutes. The predominant occlusion site was the middle cerebral artery‐M1 (45%); medium vessel occlusions occurred in 97(4.6%) patients. The median number of passes was 1 [1–3] with 93% achieving expanded Treatment In Cerebral Ischemia2b50–3 reperfusion and 51% expanded Treatment In Cerebral Ischemia3/complete reperfusion. Symptomatic intracranial hemorrhage occurred in 5.3% of patients, with 37.3% functional independence (mRS0–2) and 26.4% mortality rates at 90‐days. Multivariable regression indicated older age, longer last‐normal to reperfusion, higher baseline National Institutes of Health Stroke Scale and glucose, lower Alberta stroke program early CT score, heart failure, and general anesthesia associated with lower 90‐day chances of mRS0–2 at 90‐days. Demographic, imaging, procedural, and clinical outcomes were similar in the SVIN Registry+. A comparison between AHA Guidelines‐eligible patients from the SVIN Registry against the Highly Effective Reperfusion evaluated in Multiple Endovascular Stroke Trials study population demonstrated comparable clinical outcomes. Conclusions The prospective SVIN Registry demonstrates that satisfactory procedural and clinical outcomes can be achieved in real‐world practice, serving as a platform for local quality improvement and the investigation of unexplored frontiers in the endovascular treatment of acute 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

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

BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study\u27s 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\u3c0.0001). 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\u3c0.0001). 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

Abstract Number ‐ 84: Importance of Early Detection and Treatment of Traumatic Intracranial Pseudoaneurysms Prior to Decompressive Hemicraniectomy

Introduction Intracranial pseudoaneurysms are rare lesions that represent less than 1% of all intracranial aneurysms.1They typically occur due to disruption of the arterial wall layers and subsequent extramural/extraluminal hematoma formation following traumatic brain injury, resulting in a higher risk of rebleeding than that of saccular cerebral aneurysms.2Pseudoaneurysms have higher incidence in children and young adults, and given their association with high morbidity and mortality, early detection and management is essential.2‐4The purpose of this study is to highlight the importance of early recognition and management of traumatic pseudoaneurysms prior to decompressive hemicraniectomy. Methods This is a case report of a six‐year‐old previously healthy male who presented as a level 1 trauma alert after sustaining a gunshot wound to the face while manipulating an unsecured weapon at his residence. Upon arrival, lack of airway protection requiring intubation, entry wound to the anterior forehead, and diffuse forehead and periorbital edema were observed. CT head demonstrated multicompartmental hemorrhage with 6mm right to left midline shift and diffuse cerebral edema. CTA head and neck noted possible thrombosed right anterior cerebral artery (ACA) pseudoaneurysm in the right frontoparietal region (Figure 1‐A). Prior to decompressive hemicraniectomy, neuro‐endovascular consultation was obtained, and emergent cerebral angiogram was recommended. This case highlights the findings demonstrated on cerebral angiography, the technique by which the pseudoaneurysm was detected and secured, and the importance of doing so prior to further neurosurgical interventions. Results The patient was taken for diagnostic cerebral angiogram via femoral artery access. Initial angiographic run of the right internal carotid artery demonstrated distal right pericallosal artery slowing without clear evidence of underlying vascular injuries. Given concern for underlying thrombosed pseudoaneurysm and its parent branch, selective catheterization of the proximal pericallosal artery off the distal ACA was performed. Gentle angiographic run was obtained via microcatheter that demonstrated superior parietal artery pseudoaneurysm without active extravasation (Figure 1‐B). The microcatheter was advanced and placed in the proximal portion of the pseudoaneurysm sac and five platinum coils were deployed to fully obliterate the pseudoaneurysm and its parent feeder while protecting the adjacent paracentral artery (Figure 1‐C, 1‐D). Following completion of the endovascular procedure, the patient was transferred to the operative room for right decompressive hemicraniectomy and clot evacuation, which were completed successfully. Conclusions Prompt detection and securement of traumatic intracranial pseudoaneurysms are essential prior to invasive neurosurgical interventions to reduce risk of recurrent bleeding. Selective angiographic evaluation of the parent injured vessel(s) is crucial for optimal assessment of the underlying lesion. Neuro‐endovascular interventions including coil embolization, stenting, flow‐diverter implantation, and parental artery occlusion have emerged as alternatives to conventional neurosurgical management.2 This case highlights the successful early detection and treatment of a traumatic intracranial pseudoaneurysm with coil embolization followed by uncomplicated decompressive hemicraniectomy

Abstract Number ‐ 90: Bailout Technique for Entangled Stentriever and Carotid Stent during Tandem Large Vessel Occlusion Endovascular Therapy

Introduction Tandem occlusions represent 10–20% of all acute ischemic stroke patients.1 Endovascular Thrombectomy (EVT) for this subset of patients is more challenging given the proximal underlying steno occlusive disease. Emergent carotid artery stenting could achieve a considerably high chance of reperfusion and functional independence.2 Methods This is a case report of a 73‐year‐old woman who presented with left MCA syndrome‐NIHSS 13 found to have left ICA/MCA tandem occlusions. EVT was pursued, initial angiographic run of the left common carotid artery demonstrated severe stenosis at the origin of left cervical ICA which harbors a mid‐cervical ICA loop and proximal left MCA occlusion. Following our retrograde revascularization approach, an intracranial pass using an embotrap 5mm x 37 mm stent retriever (SR) was attempted however given proximal cervical ICA tortuosity and underlying proximal stenosis, the stability of triaxial system prevented optimal placement of the SR and achieving intracranial reperfusion. An antegrade revascularization approach was then pursued with uneventful cervical ICA angioplasty followed by extracranial carotid closed cell Xact stent placement. A stable triaxial system was navigated through the stented cervical ICA. An ideal SR pass was performed. Upon retrieving the clot‐incorporated SR with the intention to fully retrieve the SR into the locally placed aspiration catheter (AC) in the supraclinoid ICA under continuous aspiration, the triaxial system collapsed into the distal CCA, likely due to the mid cervical ICA loop, leading to entanglement of the proximal end of SR and distal ICA stent (Figure1‐A). Large thrombus was recovered from the AC aspirate. Results Numerous attempts to disentangle the SR from the ICA stent including attempts to re‐sheath the SR with different size microcatheters and guide catheters were unsuccessful. The cervical ICA lumen remained patent without evidence of dissection or residual thrombus however, the presence of SR pusher‐wire would preclude safe termination of the procedure. Surgical bailout with emergent carotid endarterectomy and removal of the stent/SR metal mesh was considered.3,4 However, given the high surgical risk with recent intravenous load of antithrombotics for emergent stent placement, this option was deemed as a last resort. We decided to attempt safe separation of the SR from its pusher wire and leave behind the patent ICA stent/SR in place. A gradual pulling pressure was applied to the SR wire while maintaining adjacent microwire access and fully inflated Viatrac 5mm x 30 mm extracranial balloon over the entangled portion to ensure continuous vascular access (Figure1‐B). The SR wire was then separated from the SR and fully retracted outside the body (Figure1‐C). Delayed angiographic runs continued to demonstrate full patency of the ICA lumen (Figure1‐D). No residual dissection, spasm or thrombus noted. Patient was discharged home with NIHSS of 3. Conclusions Exposure to EVT technical complications and bailout techniques are of utmost importance

Preclinical Large Vessel Occlusion Stroke Model: Capybaras (Hydrochoerus hydrochoeris)

Background Existing preclinical large vessel occlusion stroke models have multiple limitations. We evaluated the capybara (Hydrochoerus hydrochoeris), the largest living rodent possessing sizable cerebral cortex with gyral complexity and large caliber vessels that share many intracranial vascular attributes as seen in humans, as a potential large vessel occlusion stroke model. Methods Conventional angiography was performed in an 18‐month‐old capybara. We (1) investigated the angiographic architecture, (2) evaluated the feasibility of microcatheter navigation and stent‐retriever deployment/retraction in the intracranial vessels and the associated arterial histological changes, (3) evaluated the leptomeningeal collateral pattern following transient large vessel occlusion stroke with coil occlusion, and (4) defined the infarct topography. Results The diagnostic portion of the conventional angiogram was uneventfully performed. Five passes of a 3 mm stent‐retriever were successfully performed in the right middle cerebral artery. Transient coil occlusion of the left carotid terminus/middle cerebral artery was then pursued for 45 minutes followed by coil removal. Finally, 5 passes of a 3 mm stent‐retriever were performed at the basilar artery with unchanged final angiography. The animal was euthanized 2.5 hours after extubation. The middle cerebral and basilar arteries were resected and histopathological sampling of their proximal, mid, and distal sections was pursued. In all vessel segments in which stent retriever devices were deployed, denudation and endothelial stripping of the intima (<5% coverage) but preserved internal elastic lamina, media, and adventitia were observed. Subarachnoid hemorrhage was noted at the right Sylvian cistern. Brain histology revealed neuronal nuclear pyknosis in the left frontal cortex, left thalamus, and left hippocampal CA1 regions on hematoxilin and eosin. Luxol fast blue staining showed pallor and less conspicuous gray–white delineation, particularly in the frontal lobe. Conclusion We evaluated a novel preclinical model for thrombectomy. Capybara is a promising animal model for neurointervention. Further validation is warranted

Abstract 1122‐000128: Imaging Follow‐Up in Carotid Webs: Is There Vascular Remodeling?

Introduction: Carotid web (CaW) is a shelf‐like fibrotic projection at the carotid bulb and constitutes an underrecognized cause of ischemic stroke. Atherosclerotic lesions are known to have dynamic remodeling with time however, little is known regarding the evolution of CaW over time. We aimed to better understand if CaW is a static or dynamic entity on delayed vascular imaging. Methods: This was a retrospective analysis of the CaW database at our comprehensive stroke center, including patients diagnosed with CaW between September 2014 through June 2021. Patients who had at least two good quality CT angiograms (CTAs) that were at least 6 months apart were included (CTAs with CaW and superimposed thrombus were excluded). CaW were quantified with 3‐D measurements using Horos software. This was done via volumetric analysis of free‐hand delineated CaW borders on thin cuts of axial CTA (Figure 1 Panel A). NASCET criteria was used to evaluate the degree of stenosis. Results: Sixteen CaW in 13 patients were identified and included. The median imaging follow‐up window was 16 months (IQR 12–22, range 6–29). Median patient age was 45.5 years‐old, 69% were women, 25% had hypertension, 38% hyperlipidemia, 25% diabetes mellitus, 0% atrial fibrillation, and 13% active smokers. 75% of the included CaW were symptomatic while 25% were asymptomatic. Median volume of CaW on initial CTA (8.52 mm3 [IQR 3.7‐13], range 2.2‐30.4) was comparable to median volume of CaW on most recent CTA (8.47 mm3 [IQR 4.0‐12.8], range 2.3‐29.4; p = <0.001 (Figure 1 Panel B). The CaW volumetric measurement correlation between the initial and most recent CTA was near perfect (rs = ‐0.99, p = <0.001). The median change in measured volume of CaW between first and last CTA was ‐0.19 mm3 [IQR ‐0.6‐0.4], range ‐1‐0.8. Median degree of stenosis was 8.1% [IQR 4.5‐17.1], range 0.4‐31.2. The duration of follow‐up imaging was not correlated with the change in CaW volume (Kendall tau‐b[τb] = ‐0.17, p = 0.93). The initial CaW volume was not found to be correlated to the degree of stenosis (τb = ‐0.08, p = 0.65). Conclusions: The volume of the CaW was not found to change over time, reinforcing the idea that this is a relatively static lesion. The CaW volume was not found to correlate with the degree of stenosis caused by it. Further longitudinal studies with longer follow‐up intervals are warranted