Distal Medium Vessel Occlusion Strokes: Understanding the Present and Paving the Way for a Better Future.

Distal medium vessel occlusions (DMVOs) are thought to cause as many as 25% to 40% of all acute ischemic strokes and may result in substantial disability amongst survivors. Although intravenous thrombolysis (IVT) is more effective for distal than proximal vessel occlusions, the overall efficacy of IVT remains limited in DMVO with less than 50% of patients achieving reperfusion and about 1/3 to 1/4 of the patients failing to achieve functional independence. Data regarding mechanical thrombectomy (MT) among these patients remains limited. The smaller, thinner, and more tortuous vessels involved in DMVO are presumably associated with higher procedural risks whereas a lower benefit might be expected given the smaller amount of tissue territory at risk. Recent advances in technology have shown promising results in endovascular treatment of DMVOs with room for future improvement. In this review, we discuss some of the key technical and clinical considerations in DMVO treatment including the anatomical and clinical terminology, diagnostic modalities, the role of IVT and MT, existing technology, and technical challenges as well as the contemporary evidence and future treatment directions.

Anesthesia modality in endovascular treatment for distal medium vessel occlusion stroke: intention-to-treat propensity score-matched analysis.

BACKGROUND: The optimal anesthesia modality during endovascular treatment (EVT) for distal medium vessel occlusion (DMVO) stroke is uncertain. We aimed to evaluate the association of the anesthesia modality with procedural and clinical outcomes following EVT for DMVO stroke. METHODS: This is a multicenter retrospective analysis of a prospectively collected database. Patients were included if they had DMVO involving the middle cerebral artery-M3/4, anterior cerebral artery-A2/3, or posterior cerebral artery-P1/P2-3, and underwent EVT. The cohort was divided into two groups, general anesthesia (GA) and non-general anesthesia (non-GA), and compared based on the intention-to-treat principle as primary analysis. We used propensity scores to balance the two groups. The primary outcome was the shift in the degree of disability as measured by the 90-day modified Rankin Scale (mRS). Secondary outcomes included successful reperfusion, as well as excellent (mRS 0-1) and good (mRS 0-2) clinical outcomes at 90 days. Safety measures included procedural complications, symptomatic intracerebral hemorrhage (sICH), and 90-day mortality. RESULTS: Among 366 DMVO thrombectomies, 61 matched pairs were eligible for analysis. Median age and National Institutes of Health Stroke Scale score as well as other baseline demographic and clinical characteristics were balanced between both groups. The GA group had no difference in the overall degree of disability (common OR 1.19, 95% CI 0.52 to 2.86, P=0.67) compared with the non-GA arm. Likewise, the GA group had comparable rates of successful reperfusion (OR 2.38, 95% CI 0.80 to 7.07, P=0.12), good/excellent clinical outcomes (OR 1.14, 95% CI 0.44 to 2.96, P=0.79/(OR 0.65, 95% CI 0.24 to 1.81, P=0.41), procedural complications (OR 1.00, 95% CI 0.19 to 5.16, P>0.99), sICH (OR 3.24, 95% CI 0.83 to 12.68, P=0.09), and 90-day mortality (OR 1.43, 95% CI 0.48 to 4.27, P=0.52) compared with the non-GA group. CONCLUSIONS: In patients with DMVO, our study showed that GA and non-GA groups had similar procedural and clinical outcomes, as well as safety measures. Further larger controlled studies are warranted.

Intraoperative neuromonitoring as real-time diagnostic for cerebral ischemia in endovascular treatment of ruptured brain aneurysms.

OBJECTIVE: To evaluate the diagnostic accuracy of intraoperative neurophysiological monitoring (IONM) during endovascular treatment (EVT) of ruptured intracranial aneurysms (rIA). METHODS: IONM and clinical data from 323 patients who underwent EVT for rIA from 2014-2019 were retrospectively reviewed. Significant IONM changes and outcomes were evaluated based on visual review of data and clinical documentation. RESULTS: Of the 323 patients undergoing EVT, significant IONM changes were noted in 30 patients (9.29%) and 46 (14.24%) experienced postprocedural neurological deficits (PPND). 22 out of 30 (73.33%) patients who had significant IONM changes experienced PPND. Univariable analysis showed changes in somatosensory evoked potential (SSEP) and electroencephalogram (EEG) were associated with PPND (p-values: <0.001 and <0.001, retrospectively). Multivariable analysis showed that IONM changes were significantly associated with PPND (Odd ratio (OR) 20.18 (95%CI:7.40-55.03, p-value: <0.001)). Simultaneous changes in both IONM modalities had specificity of 98.9% (95% CI: 97.1%-99.7%). While sensitivity when either modality had a change was 47.8% (95% CI: 33.9%-62.0%) to predict PPND. CONCLUSIONS: Significant IONM changes during EVT for rIA are associated with an increased risk of PPND. SIGNIFICANCE: IONM can be used confidently as a real time neurophysiological diagnostic guide for impending neurological deficits during EVT treatment of rIA.

Assessment of the safety and efficacy of the Zoom 45 and 55 reperfusion catheters for medium and distal mechanical thrombectomies: A multi-institutional study.

INTRODUCTION: The Zoom aspiration catheters harbor novel dimensions and construction to enhance trackability and deliverability. In addition, a beveled tip may improve thrombus interaction and aspiration force for a set inner diameter. This study evaluates their utility in medium and distal vessel occlusions. OBJECTIVE: To evaluate the safety and efficacy of Zoom 45 and 55 aspiration catheters in medium and distal vessel thrombectomy. METHODS: Patients treated for distal vessel occlusions via mechanical thrombectomy utilizing either the Zoom 45/55 catheter or a historical control catheter between 2021-2022 at two institutions were included in this study. Medium and distal occlusions were defined as any anterior or posterior cerebral artery branch as well as the M2-4 segment of the middle cerebral artery (MCA). Preprocedural, procedural, and postprocedural variables were obtained. RESULTS: Thirty-eight patients underwent thrombectomy with Zoom 45 or 55 catheters; four had multiple occluded vessels. Occlusion location included the M2 in 32 cases, M3-4 in 7 cases, A2 in 2 cases and P2 in 1 case. The mean number of passes per occlusion was 1.6 and overall successful reperfusion (TICI 2b or greater) was achieved in 84 % of cases. There were no symptomatic procedure-related complications such as perforation or post-procedural symptomatic ICH. Modified Rankin scores rates of 0-2, 3-5, and 6 at three months post-procedure were 35.7 %, 21.4 %, and 42.9 %, respectively. CONCLUSIONS: The Zoom beveled tip aspiration catheters are safe and effective for more challenging medium and distal vessel occlusions.

Competitive leptomeningeal flow impact on thrombectomy reperfusion grade rating.

BACKGROUND: Competitive leptomeningeal flow (CLF) can be observed immediately after mechanical thrombectomy (MT) reperfusion with retrograde contrast clearing of the distal leptomeningeal branches from non-contrast opacified flow through different vascular territories. We aim to evaluate the frequency of the CLF phenomenon, to determine if it has an association with the degree of leptomeningeal collateral status, and to understand the potentia impact it may have on the final expanded Treatment in Cerebral Ischemia (eTICI) score rating. METHODS: Retrospective analysis of a prospective MT database spanning November 2020 to December 2021. Consecutive cases of intracranial internal carotid (i-ICA) or middle cerebral artery (MCA) M1 occlusions were included. CLF was defined by the observation of retrograde clearing of distal MCA branches that were previously opacified by antegrade reperfusion. The clearance of the distal branches is presumed to occur due to CLF via non-contrast opacified posterior cerebral artery or anterior cerebral artery flow. The washout was considered CLF if it cleared abruptly with or without forward reconstitution of antegrade opacification. RESULTS: A total of 125 patients met the inclusion criteria. The median age was 64 years (IQR 52.5-75) and 64 (51%) were men. The baseline median National Institutes of Health Stroke Scale score was 17 (IQR 12-22) and the Alberta Stroke Program Early CT Score was 9 (IQR 8-10). Median last known well time to puncture was 7 hours (IQR 4-13.1) and 30.4% received tissue plasminogen activator. Final eTICI 2c-3 was achieved in 80%. CLF was present in 32 (25.6%) patients, who had comparable baseline characteristics to patients without CLF. Twelve (37.5%) patients had regional CLF and 20 (62.5%) had focal CLF. The CLF arm had better leptomeningeal single-phase CTA collaterals than the non-CLF arm (P=0.01). The inter-rater agreement for the eTICI score was moderate when CLF was present and strong in its absence (Krippendorf's alpha=0.65 and 0.81, respectively). There was minimal agreement (Kappa=0.3) for the presence versus absence of CLF between the two operators, possibly related to reader experience. CONCLUSION: CLF was observed in 32% of patients, was associated with better collateral flow, and impacted the reported procedural eTICI rating.

Factors Affecting Selection of TraineE for Neurointervention (FASTEN).

BACKGROUND AND IMPORTANCE: Neurointervention is a very competitive specialty in the United States due to the limited number of training spots and the larger pool of applicants. The training standards are continuously updated to ensure solid training experiences. Factors affecting candidate(s) selection have not been fully established yet. Our study aims to investigate the factors influencing the selection process. METHODS: A 52-question survey was distributed to 93 program directors (PDs). The survey consisted of six categories: (a) Program characteristics, (b) Candidate demographics, (c) Educational credentials, (d) Personal traits, (e) Research and extracurricular activities, and (f) Overall final set of characteristics. The response rate was 59.1%. As per the programs' characteristics, neurosurgery was the most involved specialty in running the training programs (69%). Regarding demographics, the need for visa sponsorship held the greatest prominence with a mean score of 5.9 [standard deviation (SD) 2.9]. For the educational credentials, being a graduate from a neurosurgical residency and the institution where the candidate's residency training is/was scored the highest [5.4 (SD = 2.9), 5.4 (SD = 2.5), respectively]. Regarding the personal traits, assessment by faculty members achieved the highest score [8.9 (SD = 1)]. In terms of research/extracurricular activities, fluency in English had the highest score [7.2 (SD = 1.9)] followed by peer-reviewed/PubMed-indexed publications [6.4 (SD = 2.2)]. CONCLUSION: Our survey investigated the factors influencing the final decision when choosing the future neurointerventional trainee, including demographic, educational, research, and extracurricular activities, which might serve as valuable guidance for both applicants and programs to refine the selection process.

Thrombectomy With the pRESET vs Solitaire Stent Retrievers as First-Line Large Vessel Occlusion Stroke Treatment: A Randomized Clinical Trial.

Importance: Stent retriever-based thrombectomy is highly beneficial in large vessel occlusion (LVO) strokes. Many stent retriever designs are currently available, but comparison of these technologies in well-conducted studies is lacking. Objective: To determine whether thrombectomy for LVO stroke with the pRESET stent retriever is noninferior to treatment with the Solitaire stent retriever. Design, Setting, and Participants: This study was a multicenter, prospective, randomized, controlled, open-label, adaptive, noninferiority trial with blinded primary end point evaluation. Between October 2019 and February 2022, multicenter participation occurred across 19 research hospitals and/or universities in the US and 5 in Germany. Patients with LVO stroke were enrolled and included up to 8 hours after symptom onset. Interventions: Patients underwent 1:1 randomization to thrombectomy with the pRESET or Solitaire stent retriever. Main Outcomes and Measures: The primary outcome was the difference in the rate of 90-day functional independence across the 2 devices, using a -12.5% noninferiority margin for the lower bound of the 1-sided 95% CI of the difference between pRESET and Solitaire retrievers. Results: Of 340 randomized patients, 170 (50.0%) were female, and the median (IQR) age was 73.0 (64.0-82.0) years. The study procedure was completed in 322 of the 340 randomized patients. The primary end point of 90-day functional independence was achieved by 95 patients (54.9%; 95% CI, 48.7-61.1) in the pRESET group and in 96 (57.5%; 95% CI, 51.2-63.8) in the Solitaire group (absolute difference, -2.57%; 95% CI, -11.42 to 6.28). As the lower bound of the 95% CI was greater than -12.5%, the pRESET retriever was deemed noninferior to the Solitaire retriever. The noninferiority of pRESET over Solitaire was also observed in the secondary clinical end point (90-day shift in modified Rankin Scale score) and in both angiographic end points (Expanded Treatment in Cerebral Infarction [eTICI] score of 2b50 or greater within 3 passes: 146 of 173 [84.4%] vs 149 of 167 [89.2%]; absolute difference, -4.83%; 95% CI, -10.84 to 1.19; eTICI of 2c or greater following the first pass: 76 of 173 [43.7%] vs 74 of 167 [44.3%]; absolute difference, -0.63%; 95% CI, -9.48 to 8.21). Symptomatic intracranial hemorrhage occurred in 0 patients in the pRESET group and 2 (1.2%) in the Solitaire group. Mortality occurred in 25 (14.5%) in the pRESET group and in 24 (14.4%) in the Solitaire group at 90 days. Findings of the per-protocol and as-treated analyses were in concordance with findings of the intention-to-treat analysis. Conclusions and Relevance: In this study, among patients with LVO stroke, thrombectomy with the pRESET stent retriever was noninferior to thrombectomy with the Solitaire stent retriever. Findings suggest that pRESET offers a safe and effective option for flow restoration and disability reduction in patients with LVO stroke.

Long-term outcomes of deep pediatric arteriovenous malformations.

OBJECTIVE: Multimodality treatment has been shown to be the optimal management strategy for pediatric arteriovenous malformations (AVMs). Deep AVMs represent a subset of AVMs for which optimal management may be achieved with a combination of radiosurgery and highly selective embolization, in the absence of compelling features requiring operative intervention. The objective of this study was to identify predictors of good functional outcomes in pediatric patients with deep AVMs. METHODS: A retrospective cohort study of the outcomes of 79 patients with deep AVMs from January 1988 through December 2021 was performed. Deep AVMs were defined as those with the majority of the nidus centered in the basal ganglia, thalamus, or brainstem. Collected data included patient demographics and presenting symptoms, presenting modified Rankin Scale (mRS) score, radiographic findings and outcomes, management strategy, complications, and clinical outcomes as indicated by follow-up mRS score. A good outcome was defined as a follow-up mRS score ≤ 2, while a poor outcome was defined as a follow-up mRS score ≥ 3. Statistical analysis was performed to identify factors associated with functional outcomes. RESULTS: With a mean follow-up duration of 85.6 months, there was a 72.2% angiographic obliteration rate, with 75.9% of patients having a good clinical outcome (mRS score ≤ 2). Presenting symptoms and radiographic characteristics were not significantly associated with long-term functional outcomes. There was a significantly higher rate of posttreatment hemorrhage in patients with a poor versus good outcome (11.8% vs 0%, p = 0.010). On multivariate logistic regression analysis, poor long-term functional outcome was only associated with poor presenting mRS score (p = 0.002). CONCLUSIONS: Satisfactory angiographic obliteration rates and good long-term functional outcomes can be achieved for deep AVMs, with stereotactic radiosurgery as the cornerstone of multimodality treatment.

Flow Diverters with Surface Modification in Patients with Intracranial Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Flow diverters with surface modification (FDSM) are increasingly being used in the treatment of intracranial aneurysms (ANs). We aimed to evaluate the effectiveness and safety across different devices and antiplatelet therapies using a systematic review and meta-analysis. METHODS: A systematic review was performed to identify original studies of ≥10 patients with intracranial ANs treated with FDSM from database inception through August 2023. Primary effectiveness outcome was the rate of complete AN occlusion at follow-up ≥6 months. Safety outcomes included ischemic stroke, hemorrhage, and in-stent thrombosis, and were stratified by FDSM devices and antiplatelet therapies. Certainty of evidence was evaluated following the Grading of Recommendations, Assessment, Development, and Evaluations approach. RESULTS: Twenty-seven studies were included, yielding 2161 patients with 2373 ANs. A total of 70.5% of the ANs were located on the internal carotid artery (ICA). Total 10.3% were acutely ruptured. The complete AN occlusion rate was 72.3% at follow-up ≥6 months. Sensitivity analysis in the ICA AN cohort yielded comparable occlusion rates between Pipeline Flex Embolization Device-Shield (80.4%) and Phenox-hydrophilic polymer-coated (77.5%, P = 0.54), but a lower 66.2% rate for Flow Redirection Endoluminal Device-X (P = 0.02). The rate of in-stent thrombosis and stenosis tended to be higher in Phenox-hydrophilic polymer-coated (3.4%) and Flow Redirection Endoluminal Device-X (4.3%) versus Pipeline Flex Embolization Device-Shield (0.8%, P = 0.05). CONCLUSIONS: FDSM were safe with satisfactory effectiveness for intracranial ANs. More specific investigations are warranted to explore their performance in ANs beyond the ICA and optimal antiplatelet therapy.

Optical Coherence Tomography in the Evaluation of Suspected Carotid Webs.

BACKGROUND: Carotid web (CaW) is a subtype of fibromuscular dysplasia that predominantly involves the intimal layer of the arterial wall and is commonly overlooked as a separate causative entity for recurrent strokes. CaW is defined as a shelf-like lesion at the carotid bulb, although different morphological features have been reported. Optical coherence tomography (OCT) has been described in the literature as a useful microscopic and cross-sectional tomographic imaging tool. This study aimed to evaluate the potential utility of OCT in characterizing the wall structure features of patients with suspected CaW. METHODS: Retrospective analysis of patients with suspected CaW who underwent digital subtraction angiography (DSA) coupled with OCT of the carotid bulb from 2018 to 2021 in a single comprehensive stroke center. RESULTS: Sixteen patients were included. The median age was 56 years (IQR 46-61) and 50% were women. OCT corroborated the diagnosis of CaW in 12/16 (75%) cases and ruled it out in 4/16 (25%) patients in whom atherosclerotic disease was demonstrated. Five of the 12 lesions demonstrated a thick fibrotic ridge consistent with CaW but also showed atherosclerotic changes in the vicinity of the carotid bulb (labeled as "CaW+"). In 4/16 (25%) patients, microthrombi adhered to the vessel wall were noted on OCT (inside the CaW pocket or just distal to the web), none of which were observed on CT angiography or DSA. CONCLUSIONS: OCT may have value as a complementary imaging tool in the investigation of patients with suspected CaW and atypical morphological features. Further studies are warranted.

Emergent use of ticagrelor during endovascular reperfusion in large arterial occlusions.

OBJECTIVE: Given many emerging indications for endovascular interventions in ischemic strokes, a safe and effective adjuvant antiplatelet regimen for acute revascularization has become a subject of interest. Ticagrelor is a direct oral P2Y12 inhibitor that may achieve rapid platelet suppression than standard oral therapies. We report our experience of Ticagrelor use in revascularization of acute large arterial steno-occlusive disease, describing procedural post-procedure thrombotic events, major hemorrhages, and other clinical outcomes. METHODS: This was a single-center retrospective case series of large steno-occlusive disease requiring endovascular reperfusion with emergent adjuvant Ticagrelor, defined as 30 min of the procedure from skin puncture to closure of the arteriotomy. Major outcomes investigated were thromboembolism in the target artery, and symptomatic intracranial or extracranial major hemorrhages. Additional analyses were performed with respect to timing of the administration and use of rescue GPIIb/IIIa inhibitors if any. RESULTS: 73 consecutive patients were identified, presenting with severe ischemic stroke (median NIHSS 16) of large artery origin. 67% required stent placement (45% cervical carotid, 22% intracranial artery), 9.5% angioplasty and 23% mechanical thrombectomy only. Two experienced symptomatic in-stent occlusion, and 7 experienced major hemorrhages (9.5%) including 3 fatal symptomatic intracranial hemorrhages (4.1%). Among 19 subjects (26%) who received pretreatment with Ticagrelor, there were fewer GPIIb/IIIa administration, angioplasty and stenting, without yielding benefit in functional outcome or mortality. GPIIb/IIIa was administered as rescue therapy in 45 subjects (62%), which was found associated with increased bleeding compared to patients receiving Ticagrelor only, in whom no bleeding complications were recorded (16% vs. 0%; p = 0.03). CONCLUSION: We report our findings on Ticagrelor as an adjuvant antiplatelet therapy in ischemic stroke of large arterial origin requiring emergent revascularization. Effectiveness, safety, need for additional rescue treatment, and comparison to other commonly used oral antiplatelets should be investigated in future prospective studies.

Intracranial stenting versus aggressive medical therapy for symptomatic intracranial stenosis: A meta-analysis of multicenter randomized controlled trials and an expert assessment of the current data.

BACKGROUND: Intracranial atherosclerotic stenosis (ICAS) is associated with high risk of recurrent strokes despite best medical management (MM). We aimed to synthesize the evidence from randomized studies comparing intracranial stenting plus MM versus MM alone. METHODS: Comprehensive search of MEDLINE database was performed until May 2023. The data were extracted and pooled as risk ratio (RR) with 95% confidence interval (95% CI). RESULTS: We included three multicenter RCTs totaling 919 patients. As compared to MM alone, intracranial stenting was associated with statistically significant higher risks of any stroke or death (RR = 2.93, 95%CI [1.80-4.78], p < 0.0001), stroke in the same territory of qualifying artery (RR = 3.56, 95%CI [1.97-6.44], p < 0.0001), any ischemic stroke (RR = 2.22, 95%CI [1.27-3.87], p = 0.005), hemorrhagic stroke (RR = 13.49, 95%CI [2.59-70.15], p = 0.0002), and death (RR = 5.43, 95%CI [1.21-24.40], p = 0.003) within 30 days of randomization. There was a persistent lack of benefit and signals of harm at the last follow up within 1-3 years: any stroke or death (RR = 1.57, 95%CI [0.92-2.67], p = 0.1), stroke in the same territory of qualifying artery (RR = 1.84, 95%CI [0.97-3.50], p = 0.06), any ischemic stroke (RR = 1.56, 95%CI [1.11-2.20], p = 0.01), death (RR = 1.61, 95%CI [0.77-3.38], p = 0.2). The cumulative rate of stroke in the same territory of qualified artery with MM alone within the 1-3-year follow up was lower than expected, with only 47 out of the 450 (10.4%) MM alone patients suffering such events. CONCLUSION: The findings from this meta-analysis do not recommend stenting as a routine care option for the broader symptomatic ICAS patient population. The rates of recurrent strokes in ICAS patients managed with aggressive MM do not seem to be as high as anticipated. Additional multicenter RCTs including safer devices, larger sample sizes, and patients at higher risk of recurrent events are warranted.

Rescue intracranial stenting for failed posterior circulation thrombectomy: analysis from the Stenting and Angioplasty in NeuroThrombectomy (SAINT) study.

BACKGROUNDS: Recent trials have shown improved outcomes after mechanical thrombectomy (MT) for vertebrobasilar occlusion (VBO) stroke. However, there is a paucity of data regarding safety and outcomes of rescue intracranial stenting (RS) after failed MT (FRRS+) for posterior circulation stroke. We sought to compare RS to failed reperfusion without RS (FRRS-). METHODS: This is a retrospective analysis of the Stenting and Angioplasty in NeuroThrombectomy (SAINT) study, a multicenter collaboration involving prospectively collected databases. Patients were included if they had posterior circulation stroke and failed MT. The cohort was divided into two groups: FRRS+ and FRRS- (defined as modified Thrombolysis In Cerebral Infarction (mTICI) score 0-2a). The primary outcome was a shift in the degree of disability as measured by the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included mRS 0-2 and mRS 0-3 at 90 days. Safety measures included rates of symptomatic intracranial hemorrhage (sICH), procedural complications, and 90-day mortality. Sensitivity and subgroup analyses were performed to identify outcomes in a matched cohort and in those with VBO, respectively. RESULTS: A total of 152 failed thrombectomies were included in the analysis. FRRS+ (n=84) was associated with increased likelihood of lower disability (acOR 2.24, 95% CI 1.04 to 4.95, P=0.04), higher rates of mRS 0-2 (26.8% vs 12.5%, aOR 4.43, 95% CI 1.22 to 16.05, P=0.02) and mRS 0-3 (35.4% vs 18.8%, aOR 3.13, 95% CI 1.08 to 9.10, P=0.036), and lower mortality (42.7% vs 59.4%, aOR 0.40, 95% CI 0.17 to 0.97, P=0.04) at 90 days compared with FRRS- (n=68). The rates of sICH and procedural complications were comparable between the groups. Sensitivity and subgroup analyses showed similar results. CONCLUSION: In patients with posterior circulation stroke who had failed MT, RS resulted in better functional outcomes with comparable safety profile to procedure termination.

Comparative analysis of stenting for carotid web and atherosclerotic disease.

INTRODUCTION: Carotid Web (CaW) is an increasingly recognized etiology of ischemic stroke, and has been shown to be amenable to endovascular stenting. The technical complexity of stenting for CaW may be lower than for carotid atherosclerotic disease (CAD). We aimed to assess procedural characteristics of stenting for CaW as compared to CAD. METHODS: We retrospectively analyzed a cohort of consecutive patients at a single comprehensive stroke center from 2014 to 2021, who had undergone elective endovascular stent placement for symptomatic CAD or CaW. RESULTS: In total, 118 patients underwent elective stent placement following ischemic stroke/transient ischemic attack; 88 patients had CAD and 30 patients had CaW. CAD patients were older (63.2 vs 51.2 years, p < 0.001), less likely to be female (28.4% vs 73.3%, p < 0.001), and more likely to have pre-existing vascular risk factors. Procedure time (73.0 vs 57.5 min, p = 0.007), radiation exposure (1482 vs 1125 milliGray, p = 0.03), filter time (24 vs 14 min, p = 0.04), and use of pre-stent (68.2% vs 0%, p < 0.001) and post-stent (34.1% vs 3.3%, p < 0.001) balloon angioplasty were higher in CAD cases. There was no significant difference between groups in the rate of periprocedural complications such as hypotension, use of vasopressors, or bradycardia. Recurrent stroke/TIA was reported in five CAD patients and 0 CaW patients by the end of the follow-up period (8.3% vs 0%, p = 0.12). In-stent restenosis was detected in seven CAD patients and 0 CaW patients (10.1% vs 0%, p = 0.09) at a median follow-up of 4 vs 16 months (p = 0.01), respectively. Periprocedural intracranial hemorrhage was not observed in either group. CONCLUSION: Stenting for CaW was found to be technically simpler than CAD and not to confer increased risk of baroreceptor dysregulation. Intimal hyperplasia was uncommon in CaW cases.

Comparison of CT Perfusion Software Packages for Thrombectomy Eligibility.

INTRODUCTION: Computed tomography perfusion (CTP) has played an important role in patient selection for mechanical thrombectomy (MT) in acute ischemic stroke. We aimed to investigate the agreement between perfusion parametric maps of 3 software packages - RAPID (RapidAI-IschemaView), Viz CTP(Viz.ai), and e-CTP(Brainomix) - in estimating baseline ischemic core volumes of near completely/completely reperfused patients. METHODS: We retrospectively reviewed a prospectively maintained MT database to identify patients with anterior circulation large vessel occlusion strokes (LVOS) involving the internal carotid artery or middle cerebral artery M1-segment and interpretable CTP maps treated during September 2018 to November 2019. A subset of patients with near-complete/complete reperfusion (expanded thrombolysis in cerebral infarction [eTICI] 2c-3) was used to compare the pre-procedural prediction of final infarct volumes. RESULTS: In this analysis of 242 patients with LVOS, RAPID and Viz CTP relative cerebral blood flow (rCBF) < 30% values had substantial agreement (ρ = 0.767 [95% confidence interval [CI] = 0.71-0.81]) as well as for RAPID and e-CTP (ρ = 0.668 [95% CI = 0.61-0.71]). Excellent agreement was seen for time to maximum of the residue function (Tmax ) > 6 seconds between RAPID and Viz CTP (ρ = 0.811 [95% CI = 0.76-0.84]) and substantial for RAPID and e-CTP (ρ = 0.749 [95% CI = 0.69-0.79]). Final infarct volume (FIV) prediction (n = 136) was substantial in all 3 packages (RAPID ρ = 0.744; Viz CTP ρ = 0.711; and e-CTP ρ = 0.600). CONCLUSION: Perfusion parametric maps of the RAPID, Viz CTP, and e-CTP software have substantial agreement in predicting final infarct volume in near-completely/completely reperfused patients. ANN NEUROL 2023;94:848-855.

Estimating the impact of balloon guide catheter with mechanical thrombectomy for acute ischemic stroke: A U.S. cost analysis.

BACKGROUND: Balloon guide catheters (BGCs) can be used adjunctively during mechanical thrombectomy (MT) for acute ischemic stroke (AIS). Evaluating the potential economic impact associated with adjunctive BGC use is an important consideration for resource allocation. METHODS: Decision tree models were used to estimate the economic value of BGC use in MT through its impact on functional outcomes. Healthcare utilization cost estimates in the short- and long-term for patients with different 90-day mRS scores were analyzed for MT-only and MT + BGC scenarios. Deterministic (one-way) and probabilistic sensitivity analyses were performed to evaluate the robustness and uncertainty of model parameters. RESULTS: Per-patient index hospitalization cost was estimated at $65,260 for MT-only and $62,883 for MT + BGC scenarios. Per-patient one-year post-index hospitalization cost was estimated at $27,569 for MT-only and $24,830 for MT + BGC. MT + BGC had a total cost savings of $5117 compared with MT-only. Deterministic (one-way) sensitivity analysis demonstrated that cost saving per patient was most sensitive to the proportion of patients in the mRS 0-2 category in both MT + BGC and MT-only. In a probabilistic sensitivity analysis, mean per-patient costs for the index hospitalization were estimated at $63,737 for MT-only and $61,425 for MT + BGC. Mean per-patient cost estimates one-year post-index hospitalization was $27,445 for MT-only and $24,715 for MT + BGC. MT + BGC had a total cost savings of $5043 compared with MT-only. CONCLUSION: Mechanical thrombectomy with adjunctive BGC use may reduce short-term and long-term patient costs due to improved functional outcomes when compared to MT treatment alone for AIS.

Clot composition and recanalization outcomes in mechanical thrombectomy.

BACKGROUND: Mechanical thrombectomy (MT) has become standard for large vessel occlusions, but rates of complete recanalization are suboptimal. Previous reports correlated radiographic signs with clot composition and a better response to specific techniques. Therefore, understanding clot composition may allow improved outcomes. METHODS: Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin-eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of first-pass effect (FPE, modified Thrombolysis in Cerebral Infarction 2c/3) and the number of passes. RESULTS: A total of 1430 patients of mean±SD age 68.4±13.5 years (median (IQR) baseline National Institutes of Health Stroke Scale score 17.2 (10.5-23), IV-tPA use 36%, stent-retrievers (SR) 27%, contact aspiration (CA) 27%, combined SR+CA 43%) were included. The median (IQR) number of passes was 1 (1-2). FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for red blood cell (RBC)-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes than RBC-rich and mixed clots (median 2 and 1.5 vs 1, respectively; P=0.02). CA showed a trend towards a higher number of passes with fibrin-rich clots (2 vs 1; P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots. CONCLUSIONS: Despite the lack of correlation between clot histology and FPE, our study adds to the growing evidence supporting the notion that clot composition influences recanalization treatment strategy outcomes.

Bailout technique for entangled stent retriever and carotid stent during tandem large vessel occlusion endovascular therapy.

BACKGROUND AND IMPORTANCE: Endovascular thrombectomy for patients with tandem occlusions could be challenging. Exposure to potential technical complications and bailout rescue techniques are of utmost importance. CLINICAL PRESENTATION: A 73-year-old woman with tandem internal carotid artery and middle cerebral artery lesions underwent an unsuccessful retrograde revascularization approach in the setting of tortuous anatomy. Antegrade approach revascularization was then pursued. Following cervical internal carotid artery revascularization, a triaxial system of aspiration catheter, microcatheter and micro guidewire was navigated through the stented curved cervical ICA and intracranial stent retriever pass was performed. Upon retrieving the clot-incorporated stent retriever with the intention to retrieve the entire stent retriever into the locally placed aspiration catheter, the triaxial system collapsed into the distal common carotid artery. Large thrombus was recovered from the aspiration catheter aspirate however the proximal end of stent retriever and distal internal carotid artery stent got tangled. After unsuccessful maneuvering to disentangle stent retriever from the internal carotid artery stent, we decided to attempt safe separation of the stent retriever from its pusher wire and leave behind the patent internal carotid artery stent/stent retriever metal construct in place. Gradual pulling pressure was applied to the stent retriever wire while maintaining distal exchange-length microwire access and fully inflated extracranial balloon over the entangled portion to ensure continuous vascular access. The stent retriever wire was then safely separated from the stent retriever and fully retracted outside the body. Delayed angiographic runs continued to demonstrate full patency of the internal carotid artery lumen. No residual dissection, spasm, or thrombus was noted. CONCLUSION: This case illustrates a novel bailout endovascular salvage technique that could be considered in such cases. These techniques minimize intraoperative complication, focus on patient safety, and promote efficiency for endovascular thrombectomy in unfavorable anatomy.

Push and Fluff technique for optimization of clot integration with stent-retriever: An in vitro model.

BACKGROUND: For stent-retriever (SR) thrombectomy, technical developments such as the Push and Fluff technique (PFT) appear to have a significant impact on procedural success. This study aimed to (1) quantify the enhancement in clot traction when using PFT as compared to the standard unsheathing technique (SUT) and (2) to evaluate the performance of PFT in new versus established users of the technique. METHODS: Operators were divided between established PFT and SUT users. Each experiment was labeled according to the SR size, utilized technique, and operator experience. A three-dimensional-printed chamber with a clot simulant was used. After each retriever deployment, the SR wire was connected to a force gauge. Tension was applied by pulling the gauge until clot disengagement. The maximal force was recorded. RESULTS: A total of 167 experiments were performed. The median overall force to disengage the clot was 1.11 pounds for PFT and 0.70 pounds for SUT (an overall 59.1% increment with PFT; p < 0.001). The PFT effect was consistent across different retriever sizes (69% enhancement with the 3 × 32mm device, 52% with the 4 × 28mm, 65% with the 4 × 41mm, 47% with the 6 × 37mm). The ratio of tension required for clot disengagement with PFT versus SUT was comparable between physicians who were PFT versus SUT operators (1.595 [0.844] vs. 1.448 [1.021]; p: 0.424). The PFT/SUT traction ratio remained consistent from passes 1 to 4 of each technique in SUT users. CONCLUSION: PFT led to reproduceable improvement in clot engagement with an average ∼60% increase in clot traction in this model and was found not to have a significant learning curve.