M1 Occlusion Research Articles

Endovascular thrombectomy for acute ischemic stroke with a large infarct area: An updated systematic review and meta-analysis of randomized controlled trials

BackgroundSince the efficacy and safety of endovascular thrombectomy (EVT) in patients with acute ischemic stroke with a large infarct area is still inconclusive, we sought to compare functional and neurological outcomes with the use of endovascular thrombectomy versus medical care alone. MethodsWe searched MEDLINE (via PubMed), Embase, Cochrane Library, ClinicalTrials.gov, and the International Clinical Trials Registry Platform (ICTRP) to retrieve all the relevant randomized controlled trials (RCTs) on this topic. Review manager (RevMan) was used to perform meta-analyses using a random-effect model. Dichotomous outcomes were pooled using risk ratios (RR) with 95% confidence intervals (CIs). ResultsOur meta-analysis included 6 RCTs with a total of 1665 patients. Most studies included patients with an ASPECTS score of 3-5. Our results demonstrate that endovascular thrombectomy significantly increased the rates of functional independence (mRS ≤ 2) (RR, 2.49; 95% CI, 1.89-3.29) and moderate neurological outcome (mRS ≤ 3) (RR, 1.90; 95% CI, 1.50-2.40) at 90 days. The benefit of EVT for these outcomes remained the same at 1-year follow-up. Endovascular thrombectomy was associated with increased rates of early neurological improvement (RR, 2.22; 95% CI, 1.53-3.22), excellent neurological recovery (mRS ≤ 1) (RR, 1.75; 95% CI, 1.02-3.03), and decreased rate of poor neurological recovery (mRS 4-6) (RR, 0.81; 95% CI, 0.76-0.86). No significant difference was found between the two groups regarding all-cause mortality (RR, 0.86; 95% CI, 0.72-1.02), decompressive craniectomy (RR, 1.32; 95% CI, 0.89-1.94), and the incidence of serious adverse effects (RR, 1.39; 95% CI, 0.83-2.32) between the two groups. Endovascular thrombectomy significantly increased the rates of any intracranial hemorrhage (RR, 1.94; 95% CI, 1.48-2.53) and symptomatic intracranial hemorrhage (RR, 1.73; 95% CI, 1.11-2.69). ConclusionEndovascular thrombectomy (EVT) significantly improves neurological and functional outcomes in patients who present within 6 hours of stroke onset with ICA and proximal M1 occlusions, and ASPECTS scores ranging from 3 to 5, compared to medical therapy alone, with an increased risk of symptomatic intracranial hemorrhage.

Safety and Efficacy of Conscious Sedation Versus General Anesthesia for Distal Vessel Thrombectomy

BACKGROUND AND OBJECTIVES: Anesthesia modality for endovascular thrombectomy (EVT) for distal and medium vessel occlusions remains an open question. General anesthesia (GA) may offer advantages over conscious sedation (CS) because of reduced patient movement facilitating catheter navigation, but concerns persist about potential delays and hypotension affecting collateral circulation. METHODS: In our prospectively maintained stroke registry from December 2014 to July 2023, we identified patients with distal and medium vessel occlusions defined as M2, M3, or M4 occlusion; A1 or A2 occlusion; and P1 or P2 occlusion, who underwent EVT for acute ischemic stroke. We compared patients who received CS with those who received GA. Primary outcomes were early neurological improvement (ENI), successful reperfusion, first-pass effect, and good outcome at 90 days. Secondary outcomes included intracerebral hemorrhage, subarachnoid hemorrhage, and 90-day mortality. RESULTS: Of 279 patients, 69 (24.7%) received GA, whereas 193 (69.2%) received CS. CS was associated with higher odds of ENI compared with GA (odds ratio [OR] 2.59, 95% CI [1.04-6.98], P < .05). CS was also associated with higher rates of successful reperfusion (OR 2.33, 95% CI [1.11-4.93], P < .05). CS nonsignificantly trended toward lower rates of mortality (OR 0.51, 95% CI [0.2-1.3], P = .16). No differences in good outcome at 90 days, intracerebral hemorrhage, subarachnoid hemorrhage, or first-pass effect were seen. CONCLUSION: The use of CS during EVT seems to be safe and feasible with regard to successful recanalization, hemorrhagic complications, clinical outcome, and mortality. In addition, it may be associated with a higher rate of ENI. Further randomized studies in this specific EVT subpopulation are warranted.

Association between procedural time and outcome in unsuccessful mechanical thrombectomy for acute ischemic stroke: analysis from the Italian Registry of Endovascular Treatment in Acute Stroke.

We aim to assess the association between procedural time and outcomes in patients in unsuccessful mechanical thrombectomy (MT) for anterior circulation acute stroke. We conducted a cohort study on prospectively collected data from patients with M1 and/or M2 segment of middle cerebral artery occlusion with a thrombolysis in cerebral infarction 0-1 at the end of procedure. Primary outcome was 90-day poor outcome. Secondary outcomes were early neurological deterioration (END), symptomatic intracranial hemorrhage (sICH) according to ECASS II and sICH according to SITS-MOST. Among 852 patients, after comparing characteristics of favourable and poor outcome groups, logistic regression analysis showed age (OR: 1.04; 95%CI: 1.02-1.05; p < 0.001), previous TIA/stroke (OR: 0.23; 95%CI: 0.12-0.74; p = 0.009), M1 occlusion (OR: 1.69; 95%CI: 1.13-2.50; p = 0.01), baseline NIHSS (OR: 1.01; 95%CI: 1.06-1.13; p < 0.001) and procedural time (OR:1.00; 95% CI: 1.00-1.01; p = 0.003) as independent predictors poor outcome at 90days. Concerning secondary outcomes, logistic regression analysis showed NIHSS (OR:0.96; 95%CI: 0.93-0.99; p = 0.008), general anaesthesia (OR:2.59; 95%CI: 1.52-4.40; p < 0.001), procedural time (OR: 1.00; 95% CI: 1.00-1.01; p = 0.002) and intraprocedural complications (OR: 1.89; 95%CI: 1.02-3.52; p = 0.04) as independent predictors of END. Bridging therapy (OR:2.93; 95%CI: 1.21-7.09; p = 0.017) was associated with sICH per SITS-MOST criteria whereas M1 occlusion (OR: 0.35; 95%CI: 0.18-0.69; p = 0.002), bridging therapy (OR: 2.02; 95%CI: 1.07-3.82; p = 0.03) and intraprocedural complications (OR: 5.55; 95%CI: 2.72-11.31; p < 0.001) were independently associated with sICH per ECASS II criteria. No significant association was found between the number of MT attempts and analyzed outcomes. Regardless of the number of MT attempts and intraprocedural complications, procedural time was associated with poor outcome and END. We suggest a deeper consideration of procedural time when treating anterior circulation occlusions refractory to MT.

Comparing Outcomes of Thrombectomy Versus Intravenous Thrombolysis Based on Middle Cerebral Artery M2 Occlusion Features.

Current evidence provides limited support for the superiority of endovascular thrombectomy (EVT) in patients with M2 segment middle cerebral artery occlusion. We aim to investigate whether imaging features of M2 segment occlusion impact the effectiveness of EVT. We conducted a retrospective cohort study from January 2017 to January 2022, drawing data from the CASE II registry (Computer-Based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation), which specifically documented patients with acute ischemic stroke presenting with M2 segment occlusion undergoing reperfusion therapy. Patients were stratified into the intravenous thrombolysis (IVT) group (IVT alone) and EVT group (IVT plus EVT or EVT alone). The primary outcome was a modified Rankin Scale score 0 to 2 at 90 days. Secondary outcomes included additional thresholds and distribution of modified Rankin Scale scores, 24-hour recanalization, early neurological deterioration, and relevant complications during hospitalization. Safety outcomes encompassed intracranial hemorrhagic events at 24 hours and mortality at 90 days. Binary logistic regression analyses with propensity score matching were used. Subgroup analyses were performed based on the anatomic site of occlusion, including right versus left, proximal versus distal, dominant/co-dominant versus nondominant, single versus double/triple branch(es), and anterior versus central/posterior branch. Among 734 patients (43.3% were females; median age, 73 years) with M2 segment occlusion, 342 (46.6%) were in the EVT group. Propensity score matching analysis revealed no statistical difference in the primary outcome (odds ratio, 0.860 [95% CI, 0.611-1.209]; P=0.385) between the EVT group and IVT group. However, EVT was associated with a higher incidence of subarachnoid hemorrhage (odds ratio, 6.655 [95% CI, 1.487-29.788]; P=0.004) and pneumonia (odds ratio, 2.015 [95% CI, 1.364-2.977]; P<0.001). Subgroup analyses indicated that patients in the IVT group achieved better outcomes when presenting with right, distal, or nondominant branch occlusion (Pall interaction<0.05). Our study showed similar efficiency of EVT versus IVT alone in acute M2 segment middle cerebral artery occlusion. This suggested that only specific patient subpopulations might have a potentially higher benefit of EVT over IVT alone. URL: https://clinicaltrials.gov; Unique identifier: NCT04487340.

Outcomes and differences by occluded vessel after endovascular thrombectomy for isolated medium vessel occlusions

BackgroundThe outcomes of endovascular thrombectomy (EVT) for medium vessel occlusions (MeVOs) of specific vascular territories remain unknown. We aimed to investigate EVT outcomes by MeVO locations using the data from an ongoing international multicenter registry. MethodsPatients with isolated MeVO who underwent EVT between January 2013 and December 2022 were retrospectively analyzed. Isolated MeVO was defined as an occlusion of the A2 or A3 (A2/A3), M2 or M3, and P2 or P3 (P2/P3). Outcomes included a 90-day modified Rankin score (mRS) of 0–2, successful recanalization (modified Thrombolysis in Cerebral Infarction score ≥ 2b), early neurological deterioration (END) or improvement (ENI), and 90-day mortality. END was defined as a worsening of ≥4 points from the baseline National Institutes of Health Stroke Scale (NIHSS) score within 24 h of EVT, while ENI was defined as an improvement of ≥4 points from the baseline NIHSS score within 24 h of EVT. Results1744 MeVOs included. Compared to M2 occlusions (n = 1542, 88.4%), A2/A3 (n = 36, 2.1%) occlusions had lower odds of 90-day mRS 0–2 (adjusted odds ratio [aOR] 0.30, 95% confidence interval [CI] 0.11–0.80), and P2/P3 occlusions (n = 49, 2.8%) had lower odds of successful recanalization (aOR 0.19, 95% CI 0.07–0.50), and higher odds of END (aOR 3.53, 95% CI 1.35–9.25). Other outcomes showed no significant differences. ConclusionsA2/A3 occlusions were more likely to have worse outcomes compared to M2 occlusions after EVT for patients with isolated MeVOs.

GR.1 Standardized approach to direct first pass aspiration technique for endovascular thrombectomy: description and initial experience with CANADAPT

Background: Endovascular thrombectomy (EVT) is standard of care for acute ischemic stroke. There is growing evidence that A Direct Aspiration first Pass Technique (ADAPT) is a safe, efficient and effective approach for EVT, offering several advantages. This study describes initial institutional experience in the use of a standardized aspiration only technique: CANADAPT. Methods: Single center prospective cohort study was performed on patients treated for large/medium vessel ischemic stroke. A sequential stepwise aspiration only technique was applied, CANADAPT, consisting of three maneuvers, A, B and C. The reperfusion success rate, number of passes, use of rescue technique, complication rate and procedural cost was determined. Results: 22 patients were included representing M1 (77%), M1/2 (9%), carotid-T (9%) and basilar (5%) occlusions. First pass recanalization was achieved in 50% of patients. A further 4 patients had successful reperfusion with a second pass (total 68% success). 7 patients had stent rescue technique (SOLUMBRA). Of these, 5 patients (22% of total) had successful reperfusion. The cost per procedure was $6,630 ± 1069 for CANADAPT, and $13,530 ± 2706 for SOLUMBRA. Conclusions: CANADAPT represents a standardized approach to aspiration only thrombectomy. This study demonstrates the safety, efficiency and efficacy of this technique in EVT.

Distance to thrombus, ischemic lesion volume and clinical outcome after thrombectomy for M1 middle cerebral artery occlusion.

Stroke resulting from occlusion of the middle cerebral artery (MCA) can have devastating consequences, potentially leading to aloss of independence. This study aimed to investigate the relationship between the distance to the thrombus (DT) and both ischemic lesion volume (ILV) and clinical outcomes. We retrospectively evaluated patients with thromboembolic MCA M1 segment occlusion who underwent neurovascular imaging followed by endovascular thrombectomy (EVT) at two comprehensive stroke centers over a3-year period (2018-2020). Preinterventional computed tomography (CT) or magnetic resonance (MR) angiography was used to measure DT, defined as the distance from the carotid‑T bifurcation to the proximal surface of the M1 occlusion. Postinterventional CT or MR imaging was employed to determine the ILV and clinical outcomes were assessed using the modified Rankin scale (mRS) at 3 months. There were 346 patients evaluated. The median DT was 9.4 mm (interquartile range, IQR 6.0-13.7 mm) and the median ILV was 13.9 ml (IQR 2.2-53.1 ml). After adjustment, an increase in DT was associated with adecrease in odds for a larger ILV (odds ratio, OR 0.96, 95% confidence interval, CI 0.92-0.99, p = 0.041). Through this association, more distal thrombi were associated with good clinical outcome (mRS 0-2; clinical outcome available in 282 patients, p = 0.018). The ILV was inversely associated with better clinical outcome OR 0.52 (95% CI 0.40-0.67). Based on the findings, DT was identified as an independent albeit weak predictor for ILV and clinical outcomes in patients with MCA M1 occlusion who underwent EVT.

Comparison of 4 mm-sized and 3 mm-sized Stent Retrievers in Mechanical Thrombectomy for M2 Occlusion.

A stent retriever (SR) is widely used in mechanical thrombectomy (MT) for M2 segment occlusion. However, the suitable size of SR in M2 occlusion remains unclear. Therefore, we aimed to compare 4 mm-sized SR with 3 mm-sized SR in M2 occlusion. Patients who underwent MT with SR for M2 occlusion were dichotomized into 4×20 mm SR and 3×20 mm SR groups. Then, 1:1 propensity score matching was performed. The M2 segment was divided into proximal and distal segments according to the occlusion site. Subgroup analysis was then performed for each cohort. A total of 111 patients were enrolled, with 4×20 mm SR and 3×20 mm SR applied in 72 (64.9%) and 39 (35.1%) cases, respectively. In propensity score matching, mean number of stent passages for reperfusion was significantly lower in the 4×20 mm SR group than in the 3×20 mm SR group (1.5 ± 0.8 vs. 2.1 ± 1.1; p = 0.004). First-pass reperfusion (FPR) was more highly achieved in the 4×20 mm SR group than in the 3×20 mm SR group (52.6% vs. 42.1%; p = 0.007). In both proximal and distal occlusion cohorts, the 4 mm SR group showed lower mean number of SR passage (p = 0.004 and p = 0.003, respectively) and higher FPR rate than the 3 mm SR group (p = 0.003 and p = 0.007, respectively). In MT for M2 occlusion, 4×20 mm SR enables an effective procedure with lesser SR passage for reperfusion and a higher rate of FPR than 3×20 mm SR.

Comparison of aspiration catheter performance using adaptive pulsatile aspiration in an in vitro thrombectomy model.

Aspiration with a pump or syringe is a mainstay of mechanical thrombectomy (MT) for acute ischemic stroke (AIS), but this technology has seen minimal evolution. Non-continuous adaptive pulsatile aspiration (APA) has been proposed as a potential alternative to standard continuous aspiration as a means of improving revascularization efficiency. Using a pathophysiological flow bench model with a synthetic clot, we performed in vitro thrombectomies using the ALGO® Von Vascular, Inc. (Sunrise, FL) APA pump. A total of 25 FDA-approved aspiration catheters were tested, representing inner diameters (ID) from 0.035 in. to 0.088 in. The pump was used in 30 trials with each catheter to remove a simulated M1 occlusion. Revascularization, clot ingestion, time to clot removal, and distal embolization were measured. Among catheters tested using APA, first-pass TICI 3 revascularization was achieved in 100% of the 750 thrombectomy trials using 25 different catheters. There were no distal emboli detected in any trial run. Complete clot ingestion into the pump collection chamber was achieved in 87% to 100% of trials (overall 95%) with clot in the remaining trials corking within the catheter and removed from the model. Time from clot contact to clot removal ranged from 11 s to 90 s (mean 22.6 s, SD 16.8 s), which was negatively correlated with catheter ID (p = 0.007). APA via the Von Vascular, Inc. ALGO® pump achieved a high success rate in an in vitro MT model. All catheters tested with the pump achieved complete reperfusion in all trials, and complete clot ingestion into the pump was seen in a majority of trials. The promising in vitro performance of APA using multiple catheters warrants future in vivo investigation.

Optimizing catheter centering enhances mechanical thrombectomy success: Performance difference in cases using novel macrowires versus traditional microwires.

The aim of this study is to determine how guidewire selection impacts procedure time and success and analyze if the trend toward the adoption of larger diameter guidewires provides a quantifiable advantage over traditional 0.014″ guidewires. A review of 494 consecutively performed acute ischemic stroke cases performed between 2018 and 2022 were reviewed and grouped into cases using a single 0.014″ outer diameter (OD) guidewire (195 cases) and cases using a single 0.018″ or 0.024″ OD guidewire (128 cases). These groups were compared for differences in average time to recanalization, average number of passes to achieve recanalization, and first pass success. Cases were compared overall, and further analyzed by region of occlusion to look at specific guidewire related differences for cases with M1, M2, and ICA occlusions. Procedures using a larger OD guidewire have an average 5 min and 30 s reduction in time from puncture to recanalization (p = 0.0201). ICA occlusion cases using a larger macrowire show a 20 min reduction in recanalization time (p = 0.0005), a reduction in average number of passes from 2.6 to 1.7 (p = 0.0058), and an increase in first pass success from 18.8% to 58.3% when compared to traditional guidewires. Large 0.018″ or 0.024″ OD guidewires better fill the lumen of the catheter and help to center the thrombectomy system in the vessel and navigate to the clot face. This leads to a reduction in procedure time and number of passes, and an increase in first pass success, especially when treating occlusions in the ICA.

Stent Retriever Deployment Tracing Susceptibility Vessel Sign in the M2 Branch Predicts the Effective First-Pass Reperfusion in Thrombectomy for M1 Occlusion

Successful first-pass reperfusion is associated with better functional outcomes after mechanical thrombectomy (MT) for acute ischemic stroke, but its treatment strategies remain unclear. We retrospectively recruited patients who underwent MT for M1 occlusion between December 2020 and May 2023 at our institution. The locations of susceptibility vessel sign (SVS) on magnetic resonance imaging were classified into M1 only, M1 to single M2 branch, or M1 to both M2 branches. Patients were included in the SVS tracing group when the stent retriever of the first pass covered the entire SVS length. Successful reperfusion was defined as a modified Thrombolysis in Cerebral Infarction scale 2b-3. Any intracranial hemorrhage detected at 24-hour postoperatively was included as a hemorrhagic complication. The SVS was detected in M1 only, M1 to single M2 branch, and M1 to both M2 branches in 8, 22, and 4 patients, respectively. Among the 34 patients, 27 were included in the SVS-tracing group. Successful first-pass reperfusion was significantly more frequent in the SVS-tracing group compared with the non-SVS tracing group (odds ratio (OR), 14.4; 95% confidence interval (95%CI), 2.0-101; P = 0.007). The procedural time was significantly reduced in the SVS tracing group (median, 29 [interquartile range, 22-49] min vs. 63 [43-106] min; P = 0.043). There was a trend towards less frequent hemorrhagic complications in the SVS tracing group (OR, 0.17; 95%CI, 0.029-1.0; P = 0.052). This study provides a thrombus imaging-based MT strategy to efficiently achieve first-pass reperfusion in M1 occlusion.

Mechanical thrombectomy for middle cerebral artery M2 occlusions.

The safety and efficacy of mechanical thrombectomy (MT) for proximal large vessel occlusion after acute ischemic stroke (AIS) have been demonstrated. Clinical investigations of endovascular approaches for treating AIS due to M2 occlusions have been ongoing. To assess the outcomes of M2 occlusions according to treatment modality and anatomical division. A total of 113 consecutive M2 occlusions treated with endovascular treatment (EVT) at our tertiary stroke center between January 2019 and December 2022 were retrospectively analyzed. Patients were divided into three groups: mechanical thrombectomy (MT); intravenous thrombolysis plus MT (IVT + MT); and IVT alone. The primary outcomes were good prognosis (mRS = 0-2) and mortality (mRS = 6) on day 90. The secondary outcome was to determine the differences in outcomes between lesions in the superior and inferior branches of M2. In total, 55 (48.7%) patients underwent MT. In 42 (37.2%) patients, bridging IVT was performed with MT, and IVT alone was applied in 16 (14.2%) patients. Neither the prognosis at 90 days nor the mortality rate significantly differed among the groups. The outcomes did not significantly differ between occlusions in the superior and inferior branches of M2. MT was found to be safe and effective for treating M2 occlusions in this series.

Structural Analysis of Aspiration Catheters and Procedural Outcomes: An Analysis of the SVIN Registry

Background Rapid expansion of mechanical thrombectomy and swift manufacturing development has translated into significant evolution of large‐bore catheter technology. The objective of this study was to evaluate the association among diverse structural components of large‐bore aspiration catheters on procedural performance. Methods Retrospective analysis of a prospectively maintained mechanical thrombectomy consortium (SVIN [Society of Vascular Interventional Neurology] Registry) treated with stand‐alone contact aspiration for the first pass in the middle cerebral artery M1 or intracranial internal carotid artery occlusions from 2012 to 2021. Catheters were stratified on the basis of construction materials, tip technology, catheter sizing, and catheter lining. Factors associated with first‐pass effect (first‐pass eTICI 2c–3 reperfusion) as well as speed of clot engagement were analyzed. Results We identified 983 patients with proximal occlusion and aspiration as the first‐pass technique. First‐pass effect was observed in 34% and associated with age (odds ratio [OR], 1.02 [95% CI, 1.01–1.03]), cardioembolic stroke pathogenesis (OR, 1.69 [95% CI, 1.77–2.41]), middle cerebral artery M1 (OR, 2.74 [95% CI, 1.09–1.87]), nongeneral anesthesia (OR, 0.55 [95% CI, 0.39–0.767]), as well as with 0.070‐inch (OR, 2.04 95% CI, 1.01–3.78]), and 0.088‐inch (OR, 3.90 [95% CI, 1.58–9.61]) distal catheter inner diameter in the adjusted analysis. Mean time from arterial access to clot contact was 17 minutes, with faster times observed in younger patients (OR, 0.99 [95% CI, 0.98–0.996]) as well as with the use of aspiration catheters with shorter length of distal outer hydrophilic coating (18–30 cm) on multivariable regression (OR, 0.30 [95% CI, 0.11–0.82]). Conclusion Larger aspiration catheter distal inner diameter was associated with higher rates of first‐pass effect. Aspiration catheter construction components were found to influence times from arterial access to clot contact.

Early Neurological Deterioration in Patients with Minor Stroke due to Isolated M2 Occlusion Undergoing Medical Management: A Retrospective Multicenter Study (P1-5.019)

Early Neurological Deterioration in Patients with Minor Stroke due to Isolated M2 Occlusion Undergoing Medical Management: A Retrospective Multicenter Study (P1-5.019)

Mechanical Thrombectomy for Pediatric Arterial Ischemic Stroke from Acute M2 Occlusion.

Pediatric large-vessel occlusion has a poor natural history. Recent retrospective studies have demonstrated the potential benefits, feasibility, and safety profile of mechanical thrombectomy in children. However, the role of thrombectomy in pediatric M2 occlusions remains uncertain. In this clinical report, we present a multicenter series of 6 pediatric patients with acute M2 occlusion (female = 1, male = 5; age range, 0.9-16.0 years, mean = 9.2). All 6 patients having undergone thrombectomy had excellent clinical outcomes (pediatric mRS = 0-1) at 3 months and final available follow-up (median, 12 months; range, 3-72 months). Factors relevant to treatment decision-making in pediatric M2 occlusions are discussed, including the important role of multidisciplinary team discussions during acute management.

Evaluation of the relationship between computed tomography angiography collateral scores and clinical outcome.

The relationship between collateral circulation and prognosis after endovascular treatment in anterior circulation strokes has been reported in many studies. In this study, we aimed to compare the predictive power of clinical outcome by comparing five different collateral scores that are frequently used. Among the patients who underwent endovascular treatment in our clinic between November 2019 and December 2021, patients with premorbid mRS < 3, intracranial ICA and/or MCA M1 occlusion, and a pre-procedural multiphase CTA examination were included in the study. Demographic, technical, and duration information about the procedure, major events after the procedure, and clinical outcomes at 3 months were recorded. The mCTA, Tan, Maas, Miteff, and rLMC collateral scores of the patients were evaluated. Clinical outcome at 3 months were good in 37 of the 68 patients included in the study (mRS ≤ 2). Only the mCTA and rLMC collateral scores were statistically significantly higher in those with a good clinical outcome. Significant correlation with 3-month mRS was detected only in mCTA and rLMC scores. Although rLMC and mCTA collateral scores showed a statistically significant association with prognosis, they were not sufficient to be an independent predictor of prognosis. mCTA and rLMC were found to have the highest predictive power of clinical outcome and the highest correlation with the 3-month clinical outcome. Our study suggests that it would be beneficial to develop a new scoring system over multiphase CTA, which combines regional and temporal evaluation, which are the strengths of both collateral scoring.

Feasibility of super-bore 0.088″ mechanical thrombectomy in M1 vessels smaller than 8 French: Experience in 20 consecutive cases.

Superbore 0.088″ catheters provide a platform for optimizing aspiration efficiency and flow control during stroke mechanical thrombectomy procedures. New superbore catheters have the distal flexibility necessary to navigate complex neurovascular anatomy while providing the proximal support of traditional 8F catheters. The safety and feasibility of Zoom 88™ superbore angled-tip catheters in the middle cerebral artery (MCA) segments smaller than the catheter diameter have not been previously described. Twenty consecutive cases of acute MCA mechanical thrombectomy were retrospectively identified from the senior authors' prospectively maintained Institutional Review Board-approved database, in which the Zoom 88 (Imperative Care, Campbell, CA) catheter was successfully navigated to at least the M1 segment. Patient demographics, procedural details, and periprocedural information were analyzed. Rates and averages (standard errors) are generally reported. The average National Institutes of Health Stroke Scale at presentation and age were 15 ± 2 and 73 ± 3 years, respectively. The M1 and M2 occlusions were evenly distributed. The average M1 measurements before thrombectomy ranged from 2.36 ± 0.07 mm proximally to 2.00 ± 0.11 mm distally, and after thrombectomy, they ranged from 2.34 ± 0.07 mm proximally to 1.97 ± 0.10 mm distally. First-pass modified thrombolysis in cerebral infarction (mTICI) 2C/3 recanalization was achieved in 40% of cases, and final mTICI 2C/3 recanalization was achieved in 90% of cases. A single case of mild vasospasm was managed with verapamil. No hemorrhagic or periprocedural complications were noted. Superbore 0.088″ catheters with flexible distal segments can be safely navigated to the MCA to augment mechanical thrombectomy even when the MCA segment is smaller than the catheter.

Effect of concomitant usage of alteplase and mechanical thrombectomy for M1 middle cerebral artery occlusion on clinical outcome: a retrospective analysis of 457 patients from two centers.

Endovascular thrombectomy (EVT) and concomitant usage of intravenous alteplase (alteplase) in large vessel occlusion stroke may produce unwanted excess intracerebral hemorrhage (ICH). Whether this applies specifically to isolated occlusion of the M1 segment of the middle cerebral artery (MCA) is unknown. A retrospective study from two tertiary thrombectomy centers. ICH was determined according to Heidelberg Bleeding Classification (HBC). Factors associated with the occurrence of ICH in EVT alone vs. EVT with alteplase were evaluated using logistic regression analysis. Factors related to the clinical outcome as determined with a modified Rankin scale (mRS) were investigated with univariate and adjusted multivariate logistic regression analysis. The interaction between clinical variables and the usage of alteplase on the occurrence of ICH was evaluated. Any ICH occurred in 156/457 (34.1%) patients Class 1a bleeding in 37 (8.1%), type 2 in 45 (9.8%) Class 1c in 22 (4.8%), Class 2 in 25 (5.5%), and Class 3 (extraparenchymal) in 27 (5.9%). ICH occurred in similar frequency between alteplase-treated patients vs. EVT alone (85/262 [32%] vs. 71/195 [36%]; OR 1.19 (95% CI 0.81-1.76). After adjustment, odds for clinical outcome were lower in ICH patients (OR 0.44 [95% CI 0.25-0.74]), p = 0.002). Higher ICH rate was associated with more EVT steps (p for interaction -0.005), and usage of only stent-retriever (p for interaction =0.005). Utilization of alteplase alongside EVT for MCA M1 occlusion did not result in excessive ICH occurrences or clinical deterioration.

Late Lesion Growth following Endovascular Therapy: Is 24 h Too Early to Assess Acute Infarct Size Including the Effects of Secondary Injury?

Introduction: Stroke lesion volume on MRI or CT provides objective evidence of tissue injury as a consequence of ischemic stroke. Measurement of “final” lesion volume at 24-h following endovascular therapy (post-EVT) has been used in multiple studies as a surrogate for clinical outcome. However, despite successful recanalization, a significant proportion of patients do not experience favorable clinical outcome. The goals of this study were to quantify lesion growth during the first week after treatment, identify early predictors, and explore the association with clinical outcome. Methods: This is a prospective study of stroke patients at two centers who met the following criteria: (i) anterior large vessel occlusion acute ischemic stroke, (ii) attempted EVT, and (iii) had 3T MRI post-EVT at 24-h and 5-day. We defined “early” and “late” lesion growth as ≥10 mL lesion growth between baseline and 24-h diffusion-weighted imaging (DWI) and between 24-h DWI and 5-day fluid attenuated inversion recovery imaging, respectively. Complete reperfusion was defined as >90% reduction of the volume of tissue with perfusion delay (Tmax>6 s) between pre-EVT and 24-h post-EVT. Favorable clinical outcome was defined as modified Rankin scale (mRS) of 0–2 at 30 or 90 days. Results: One hundred twelve patients met study criteria with median age 67 years, 56% female, median admit NIHSS 19, 54% received IV or IA thrombolysis, 66% with M1 occlusion, and median baseline DWI volume 21.2 mL. Successful recanalization was achieved in 87%, and 68% had complete reperfusion, with an overall favorable clinical outcome rate of 53%. Nearly two-thirds (65%) of the patients did not have late lesion growth with a median volume change of −0.3 mL between 24-h and 5-day and an associated high rate of favorable clinical outcome (64%). However, ∼1/3 of patients (35%) did have significant late lesion growth despite successful recanalization (87%: 46% mTICI 2b/41% mTICI 3). Late lesion growth patients had a 27.4 mL change in late lesion volume and 30.1 mL change in early lesion volume. These patients had an increased hemorrhagic transformation (HT) rate of 68% with only 1 in 3 patients having favorable clinical outcome. Late lesion growth was independently associated with incomplete reperfusion, HT, and unfavorable outcome. Conclusion: Approximately 1 out of 3 patients had late lesion growth following EVT, with a favorable clinical outcome occurring in only 1 out of 3 of these patients. Most patients with no early lesion growth had no late lesion growth. Identification of patients with late lesion growth could be critical to guide clinical management and inform prognosis post-EVT. Additionally, it can serve as an imaging biomarker for the development of adjunctive therapies to mitigate reperfusion injury.

Comparison between transradial and transfemoral mechanical thrombectomy for ICA and M1 occlusions: insights from the Stroke Thrombectomy and Aneurysm Registry (STAR)

BackgroundThe role for the transradial approach for mechanical thrombectomy is controversial. We sought to compare transradial and transfemoral mechanical thrombectomy in a large multicenter database of acute ischemic stroke.MethodsThe prospectively...