Thrombectomy in Stroke Patients With Low Alberta Stroke Program Early Computed Tomography Score: Is Modified Thrombolysis in Cerebral Infarction (mTICI) 2c/3 Superior to mTICI 2b?

BACKGROUND AND PURPOSE: Outcomes following mechanical thrombectomy (MT) are strongly correlated with successful recanalization, traditionally defined as modified Thrombolysis in Cerebral Infarction (mTICI) ≥2b. This retrospective cohort study aimed to compare the outcomes of patients with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS; 2-5) who achieved mTICI 2b versus those who achieved mTICI 2c/3 after MT. METHODS: This study utilized data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which combined databases from 32 thrombectomy-capable stroke centers between 2013 and 2023. The study included only patients with low ASPECTS who achieved mTICI 2b, 2c, or 3 after MT for internal carotid artery or middle cerebral artery (M1) stroke. RESULTS: Of the 10,229 patients who underwent MT, 234 met the inclusion criteria. Of those, 98 (41.9%) achieved mTICI 2b, and 136 (58.1%) achieved mTICI 2c/3. There were no significant differences in baseline characteristics between the two groups. The 90-day favorable outcome (modified Rankin Scale score: 0-3) was significantly better in the mTICI 2c/3 group than in the mTICI 2b group (adjusted odds ratio 2.35; 95% confidence interval [CI] 1.18-4.81; P=0.02). Binomial logistic regression revealed that achieving mTICI 2c/3 was significantly associated with higher odds of a favorable 90-day outcome (odds ratio 2.14; 95% CI 1.07-4.41; P=0.04). CONCLUSION: In patients with low ASPECTS, achieving an mTICI 2c/3 score after MT is associated with a more favorable 90-day outcome. These findings suggest that mTICI 2c/3 is a better target for MT than mTICI 2b in patients with low ASPECTS.

Continuing early mTICI 2b recanalization may improve functional outcome but is associated with a higher risk of intracranial hemorrhage.

Background: Successful reperfusion (mTICI 2c/3) and low number of passes are key determinants for good clinical outcome in acute large vessel occlusion. While final mTICI 2c/3 reperfusion is superior to partial reperfusion (mTICI 2b) it remains unclear if this is also true for the subgroup of patients with early mTICI 2b (achieved in ≤2 retrieval attempts) reperfusion who are secondarily improved to mTICI 2c/3. This study was designed to examine if early mTICI2b should be continued or stopped during mechanical thrombectomy (MT). Methods: Nine hundred and thirteen ischemic stroke patients who received MT were retrospectively analyzed. Angiography runs following each recanalization attempt were scored for mTICI. The patients with early mTICI 2b reperfusions were dichotomized in "TICI2b-stopped" (MT withdrawal after mTICI 2b was achieved with first or second retrieval) and "TICI2b-continued" (MT was continued after mTICI 2b was achieved with first or second retrieval). Functional outcome was obtained after 90 days using the modified Rankin scale (mRS90). Results: Of 362 Patients with a M1-occlusion, 100 patients fulfilled the inclusion criteria with an early mTICI 2b. 78/100 patients were included in the "TICI2b-stopped" group and 22/100 patients were in the "TICI2b-continued" group. Of these 22 patients, none had a final mTICI score lower than 2b and 11 patients had a final mTICI score of 2c/3. Regarding good functional outcome at mRS90, "TICI2b-continued" showed by trend a slight advantage of 40.1 vs. 35.6% in "TICI2b-stopped" but in multivariate logistic regression analysis adjusted for confounders, no significant difference was found between the two groups (OR 0.75, 95% CI 0.19-2.87, p = 0.67). Symptomatic intracranial hemorrhage was significantly higher in "TICI2b-continued" compared to "TICI2b-stopped" (31.8 vs. 10.3%, p = 0.031). Conclusion: Successfully improving an early mTICI 2b to mTICI 2c/3 reperfusion is possible in a substantial number of patients and might improve functional outcome. However, an increase in symptomatic intracranial hemorrhage (SICH) due to further retrieval attempts may diminish the potential functional benefit to continue early mTICI 2b. To support this finding, further investigation with more power is needed to account for the low number of events regarding SICH.

Convulsive-like symptoms as initial indications of basilar artery occlusion: A case series study.

BACKGROUND: There is little evidence regarding relevant clinical findings for the early diagnosis of basilar artery occlusion (BAO) in the prehospital setting. We focused on "convulsive-like symptoms", including convulsive seizures and other convulsive-like movements, and examined the frequency and clinical characteristics of patients with BAO having these symptoms as an initial symptom. METHODS: In this single-center case series from 2015 to 2020, we identified patients who underwent endovascular therapy (EVT) for BAO and presented with convulsive-like symptoms between the stroke onset and initiation of emergency medical care. The clinical course and neurological findings were evaluated by reviewing the run sheets of emergency medical services and medical records. RESULTS: Among a total of 32 patients with BAO, 7 (21.9%) developed convulsive-like symptoms before EVT, of whom 6 were men and whose median age was 72 (interquartile range, 69-78) years. These 7 patients had no history of epilepsy or stroke, and the semiology of convulsive-like symptoms was generalized in 6 of them. In only 3 of the 7 cases, emergency medical services could consider the possibility of stroke on scene, and time from hospital arrival to groin puncture was longer in those who were transported without suspicion of stroke. CONCLUSIONS: 21.9% of our patients who underwent EVT for BAO experienced convulsive-like symptoms initially. We should be vigilant in the possibility of BAO when managing the first-time generalized convulsive-like symptoms occurring in older patients, which may enable to adequate triage and better management for patients with acute BAO.

Association of CHA2DS2-VASc score with successful recanalization in acute ischemic stroke patients undergoing endovascular thrombectomy.

Introduction: The CHA2DS2-VASc (congestive heart failure, hypertension, age, diabetes mellitus, stroke, vascular disease and sex) score is a simple risk stratification algorithm to estimate stroke/thromboembolic risk in patients with non-valvular atrial fibrillation (AF). Higher pre-stroke CHA2DS2-VASc score is known to be associated with greater stroke severity and poorer outcomes. AF patients generally have higher CHA2DS2-VASc scores than non-AF patients. The Modified Thrombolysis in Cerebral Infarction (mTICI) score is the most widely used grading system to assess the result of recanalizing therapies in acute ischemic stroke (AIS). mTICI 2c and mTICI 3 are conventionally accepted as successful recanalization. Aim: We investigated whether pre-stroke CHA2DS2-VASc score is associated with mTICI recanalization score in AIS patients with and without AF undergoing percutaneous thrombectomy. Material and methods: One hundred fifty-nine patients with the diagnosis of AIS who were admitted within 6 h from symptom onset were included in the study (mean age: 65.7 ±12.9). All subjects underwent endovascular treatment. CHA2DS2-VASc scores of the participants were calculated. Subjects were grouped according to mTICI scores achieved after endovascular treatment. mTICI 2c and mTICI 3 were accepted as successful recanalization. Results: Successful reperfusion was observed in 130 (81.8%) of all patients who underwent endovascular treatment (mTICI flow ≥ 2c) and first-pass reperfusion was observed in 107 (67.3%) patients. When the patients with successful (mTICI flow ≥ 2c) and unsuccessful (mTICI flow ≤ 2b) reperfusion were divided into groups, no significant difference was observed between the patients in terms of comorbidities such as AF, hypertension, hyperlipidemia, coronary artery disease and cerebrovascular accident history. Patients with unsuccessful reperfusion were older than patients with successful reperfusion (71.4 ±11.2 vs. 64.5 ±13.01, p = 0.006), with a higher CHA2DS2-VASc score (4.1 ±1.5 vs. 3.04 ±1.6, p = 0.002). In addition, the duration of the procedure was longer in the unsuccessful reperfusion group (92.4 ±27.2 min vs. 65.0 ±25.1 min, p < 0.001). CHA2DS2-VASc score significantly correlated with successful recanalization (correlation coefficient; 0.243, p = 0.002). Multivariate logistic regression analysis revealed that only CHA2DS2-VASc score (OR = 1.43, 95% CI: 1.09-1.87, p = 0.006) and procedure time (OR = 1.03, 95% CI: 1.01-1.05, p < 0.001) were independent predictors of successful reperfusion. The receiver-operating characteristic (ROC) curve was used to determine the cut-off value for the CHA2DS2-VASc score that best predicts successful reperfusion. The optimal threshold was 3.5, with a sensitivity of 58.6% and specificity of 59.2% (area under the curve (AUC): 0.669, p = 0.005). Conclusions: For the first time in the literature, we investigated and demonstrated that pre-stroke CHA2DS2-VASc score was associated with success of recanalization as assessed with mTICI 2c and mTICI 3 in a cohort of AIS patients regardless of AF presence who underwent endovascular treatment. Our findings deserve to be tested with large scale long term studies.

Identification of successful cerebral reperfusions (mTICI ≥2b) using an artificial intelligence strategy.

BACKGROUND: The modified thrombolysis in cerebral infarction (mTICI) scale is a widely used and validated qualitative tool to evaluate angiographic intracerebral inflow following endovascular thrombectomy (EVT). We validated a machine-learning (ML) algorithm to grade digital subtraction angiograms (DSA) using the mTICI scale. MATERIALS AND METHODS: We included angiograms of identified middle cerebral artery (MCA) occlusions who underwent EVT. The complete DSA sequences were preprocessed and normalized. We created three convolutional neural networks to classify DSA into two outcomes, low- (mTICI 0,1,2a) and high-grade (mTICI 2b,2c,3). RESULTS: We included a total of 234 angiograms in this study. The area under the receiver operating characteristic was 0.863 (95% CI 0.816-0.909), 0.914 (95% CI 0.876-0.951), and 0.890 (95% CI 0.848-0.932) for the anteroposterior (AP), lateral (L), and combined models, respectively, when dichotomizing outcomes into low and high grade. The models' area under the precision-recall curve was 0.879 (95% CI 0.829-0.930), 0.906 (95% CI 0.844-0.968), and 0.887 (95% CI 0.834-0.941) for the AP, L, and combined models. CONCLUSION: In complete cerebral DSA, our angiography-based ML strategy was able to predict mTICI scores following EVT rapidly and reliably for MCA occlusions.

Mechanical thrombectomy in pediatric stroke: systematic review, individual patient data meta-analysis, and case series.

OBJECTIVE: The role of mechanical thrombectomy in pediatric acute ischemic stroke is uncertain, despite extensive evidence of benefit in adults. The existing literature consists of several recent small single-arm cohort studies, as well as multiple prior small case series and case reports. Published reports of pediatric cases have increased markedly since 2015, after the publication of the positive trials in adults. The recent AHA/ASA Scientific Statement on this issue was informed predominantly by pre-2015 case reports and identified several knowledge gaps, including how young a child may undergo thrombectomy. A repeat systematic review and meta-analysis is warranted to help guide therapeutic decisions and address gaps in knowledge. METHODS: Using PRISMA-IPD guidelines, the authors performed a systematic review of the literature from 1999 to April 2019 and individual patient data meta-analysis, with 2 independent reviewers. An additional series of 3 cases in adolescent males from one of the authors' centers was also included. The primary outcomes were the rate of good long-term (mRS score 0-2 at final follow-up) and short-term (reduction in NIHSS score by ≥ 8 points or NIHSS score 0-1 at up to 24 hours post-thrombectomy) neurological outcomes following mechanical thrombectomy for acute ischemic stroke in patients < 18 years of age. The secondary outcome was the rate of successful angiographic recanalization (mTICI score 2b/3). RESULTS: The authors' review yielded 113 cases of mechanical thrombectomy in 110 pediatric patients. Although complete follow-up data are not available for all patients, 87 of 96 (90.6%) had good long-term neurological outcomes (mRS score 0-2), 55 of 79 (69.6%) had good short-term neurological outcomes, and 86 of 98 (87.8%) had successful angiographic recanalization (mTICI score 2b/3). Death occurred in 2 patients and symptomatic intracranial hemorrhage in 1 patient. Sixteen published thrombectomy cases were identified in children < 5 years of age. CONCLUSIONS: Mechanical thrombectomy may be considered for acute ischemic stroke due to large vessel occlusion (ICA terminus, M1, basilar artery) in patients aged 1-18 years (Level C evidence; Class IIb recommendation). The existing evidence base is likely affected by selection and publication bias. A prospective multinational registry is recommended as the next investigative step.

Mechanical thrombectomy using a Solitaire stent retriever in the treatment of pediatric acute ischemic stroke.

OBJECTIVE Mechanical thrombectomy using a Solitaire stent retriever has been widely applied as a safe and effective method in adult acute ischemic stroke (AIS). However, due to the lack of data, the safety and effectiveness of mechanical thrombectomy using a Solitaire stent in pediatric AIS has not yet been verified. The purpose of this study was to explore the safety and effectiveness of mechanical thrombectomy using a Solitaire stent retriever for pediatric AIS. METHODS Between January 2012 and December 2017, 7 cases of pediatric AIS were treated via mechanical thrombectomy using a Solitaire stent retriever. The clinical practice, imaging, and follow-up results were reviewed, and the data were summarized and analyzed. RESULTS The ages of the 7 patients ranged from 7 to 14 years with an average age of 11.1 years. The preoperative National Institutes of Health Stroke Scale (NIHSS) scores ranged from 9 to 22 with an average of 15.4 points. A Solitaire stent retriever was used in all patients, averaging 1.7 applications of thrombectomy and combined balloon dilation in 2 cases. Grade 3 on the modified Thrombolysis In Cerebral Infarction scale of recanalization was achieved in 5 cases and grade 2b in 2 cases. Six patients improved and 1 patient died after thrombectomy. The average NIHSS score of the 6 cases was 3.67 at discharge. The average modified Rankin Scale score was 1 at the 3-month follow-up. Subarachnoid hemorrhage after thrombectomy occurred in 1 case and that patient died 3 days postoperatively. CONCLUSIONS This study shows that mechanical thrombectomy using a Solitaire stent retriever has a high recanalization rate and excellent clinical prognosis in pediatric AIS. The safety of mechanical thrombectomy in pediatric AIS requires more clinical trials for confirmation. ABBREVIATIONS ACA = anterior cerebral artery; AIS = acute ischemic stroke; CTA = CT angiography; ICA = internal carotid artery; MCA = middle cerebral artery; mRS = modified Rankin Scale; mTICI = modified Thrombolysis In Cerebral Infarction; NIHSS = National Institutes of Health Stroke Scale; rt-PA = recombinant tissue plasminogen activator.

Diffusion-weighted imaging lesion growth occurs despite recanalization in acute ischemic stroke: Implications for future treatment trials.

BACKGROUND: A proportion of patients presenting with acute small ischemic strokes have poor functional outcomes, even following rapid recanalization treatment. AIMS: Infarct growth may occur even after successful recanalization and could represent an appropriate endpoint for future stroke therapy trials. METHODS: Magnetic resonance diffusion-weighted imaging lesion volumes were obtained at 5 h (initial posttreatment) and 24 h (follow-up) after acute stroke treatment for n = 33 in ischemic stroke patients. Sample sizes per arm (90% power, 30% effect size) for diffusion-weighted imaging lesion growth between initial and 24 h, early change in the National Institutes of Health Stroke Scale between pre- and 24 h, National Institutes of Health Stroke Scale at 24 h, and diffusion-weighted imaging lesion volume at 24 h were estimated to power a placebo-controlled stroke therapy trial. RESULTS: For patients with poor recanalization (modified thrombolysis in cerebral infarction <2 a; modified arterial occlusion lesion = 0-2) (n = 11), the median diffusion-weighted imaging lesion growth was 8.1 (interquartile range: 4.5, 22.4) ml and with good recanalization (modified thrombolysis in cerebral infarction =2 b or 3; modified arterial occlusion lesion = 3) (n = 22), the median diffusion-weighted imaging lesion growth was 10.0 (interquartile range: 6.0, 28.2) ml ( P = 0.749). When considering a 30% effect size, the sample size required per arm to achieve significance in an acute stroke study would be: (1) N = 49 for the diffusion-weighted imaging lesion growth between initial posttreatment and follow-up time points, (2) N = 65 for the change in the National Institutes of Health Stroke Scale between admission and 24 h, (3) N = 259 for the National Institutes of Health Stroke Scale at 24 h, and (4) N = 256 for diffusion-weighted imaging volume at 24 h. CONCLUSION: Despite best efforts to recanalize the ischemic brain, early diffusion-weighted imaging lesion growth still occurs. Treatment trials in stroke should consider early diffusion-weighted imaging lesion growth as a surrogate outcome measure to significantly reduce sample sizes.

Effect of balloon guide catheter utilization on contact aspiration thrombectomy.

OBJECTIVEThe role of the balloon guide catheter (BGC) has not been evaluated in contact aspiration thrombectomy (CAT) for acute stroke. Here, the authors aimed to test whether the BGC was associated with recanalization success and good functional outcome in CAT.METHODSAll patients who had undergone CAT as the first-line treatment for anterior circulation intracranial large vessel occlusion were retrospectively identified from prospectively maintained registries for six stroke centers. The patients were dichotomized into BGC utilization and nonutilization groups. Clinical findings, procedural details, and recanalization success rates were compared between the two groups. Whether the BGC was associated with recanalization success and functional outcome was assessed.RESULTSA total of 429 patients (mean age 68.4 ± 11.4 years; M/F ratio 215:214) fulfilled the inclusion criteria. A BGC was used in 45.2% of patients. The overall recanalization and good outcome rates were 80.2% and 52.0%, respectively. Compared to the non-BGC group, the BGC group had a significantly reduced number of CAT passes (2.6 ± 1.6 vs 3.4 ± 1.5), shorter puncture-to-recanalization time (56 ± 27 vs 64 ± 35 minutes), lower need for the additional use of thrombolytics (1.0% vs 8.1%), and less embolization to a distal or different site (0.5% vs 3.4%). The BGC group showed significantly higher final (89.2% vs 72.8%) and first-pass (24.2% vs 8.1%) recanalization success rates. After adjustment for potentially associated factors, BGC utilization remained independently associated with recanalization (OR 4.171, 95% CI 1.523-11.420) and good functional outcome (OR 2.103, 95% CI 1.225-3.612).CONCLUSIONSBGC utilization significantly increased the final and first-pass recanalization rates and remained independently associated with recanalization success and good functional outcome.

Different learning curves between stent retrieval and a direct aspiration first-pass technique for acute ischemic stroke.

OBJECTIVEThe clinical outcomes of a direct aspiration first-pass technique (ADAPT) and stent retriever (SR) have been reported to be similar in several observational studies. In this study, procedural and clinical outcomes with ADAPT and SR for the treatment of acute ischemic stroke with large artery occlusion were compared in different time periods.METHODSIn each specific time period, SR and ADAPT were used as the first-line treatment approach for acute ischemic stroke patients with large artery occlusion at the authors' institution. Baseline characteristics, procedural variables, and functional outcome at 90 days were compared between patients treated with SR and those treated with ADAPT. These 2 groups were divided into 3 sequential subgroups to assess the learning curve effects of the endovascular team and individual operators on the procedural variables of each treatment strategy.RESULTSOverall, 89 patients were treated. In the SR group, the recanalization rate was higher (84% vs 65%; p = 0.01) and the procedure time was shorter than in the ADAPT group (median 42 minutes vs 76 minutes, p = 0.04). On the subgroup analysis of the learning curve, the SR group showed more rapid improvement in procedure time than the ADAPT group (p = 0.01 for the team; p < 0.01 for individual operators).CONCLUSIONSIn this initial experience, a higher recanalization rate and shorter procedure time were achieved with SR than with ADAPT. A high recanalization rate with SR was possible with relatively less clinical experience, whereas procedure time dramatically decreased with experience. These observed effects on the learning curve might be useful when choosing the method for initial endovascular treatment of acute ischemic stroke at relatively small stroke centers.