Clarifying differences among thrombolysis in cerebral infarction scale variants: is the artery half open or half closed?

Movement disorders following mechanical thrombectomy resulting in ischemic lesions of the basal ganglia: An emerging clinical entity

BACKGROUND AND PURPOSE

Post-stroke movement disorders (PMDs) following ischemic lesions of the basal ganglia (BG) are a known entity, but data regarding their incidence are lacking. Ischemic strokes secondary to proximal middle cerebral artery (MCA) occlusion treated with thrombectomy represent a model of selective damage to the BG. The aim of this study was to assess the prevalence and features of movement disorders after selective BG ischemia in patients with successfully reperfused acute ischemic stroke (AIS).

METHODS

We enrolled 64 consecutive subjects with AIS due to proximal MCA occlusion treated with thrombectomy. Patients were clinically evaluated by a movement disorders specialist for PMDs onset at baseline, and after 6 and 12 months.

RESULTS

None of the patients showed an identifiable movement disorder in the subacute phase of the stroke. At 6 and 12 months, respectively, 7/25 (28%) and 7/13 (53.8%) evaluated patients developed PMDs. The clinical spectrum of PMDs encompassed parkinsonism, dystonia and chorea, either isolated or combined. In most patients, symptoms were contralateral to the lesion, although a subset of patients presented with bilateral involvement and prominent axial signs.

CONCLUSION

Post-stroke movement disorders are not uncommon in long-term follow-up of successfully reperfused AIS. Follow-up conducted by a multidisciplinary team is strongly advisable in patients with selective lesions of the BG after AIS, even if asymptomatic at discharge.

Basal ganglia ischaemic infarction after thrombectomy: cognitive impairment at acute stage

BACKGROUND AND PURPOSE

After successful mechanical thrombectomy for middle cerebral artery occlusion, basal ganglia infarction is commonly detectable. Whilst the functional outcome of these patients is often good, less knowledge is available about the cognitive outcome. The aim of our study was to assess the presence of cognitive impairment within 1 week after thrombectomy.

METHODS

In all, 43 subjects underwent a general cognitive assessment using the Montreal Cognitive Assessment and an extensive battery of tests. Patients were classified as cognitively impaired (CImp) or not (noCImp) according to a Montreal Cognitive Assessment score below 18.

RESULTS

Cognitively impaired and noCImp subjects did not differ either in their National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) at admittance, or in their Fazekas score and Alberta Stroke Program Early Computed Tomography Score. At discharge, CImp subjects showed higher scores than noCImp subjects on NIHSS (p = 0.002) and mRS (p < 0.001). The percentage of pathological performances on each neuropsychological test in the whole sample and in CImp and noCImp patients shows a similar cognitive profile between the groups.

CONCLUSIONS

Some patients who underwent thrombectomy experienced a detectable cognitive impairment that probably led to worse NIHSS and mRS. The neuropsychological profile of such cognitive impairment at the acute stage consists of wide deficits in numerous cognitive domains, suggesting that basal ganglia damage may lead to complex functional impairments.

Long-Term Benefit of Mechanical Thrombectomy for Acute Ischemic Stroke in Patients with a Left Ventricular Assist Device: A Single-Center Retrospective Study

OBJECTIVE

Left ventricular assist devices (LVADs) are an epoch-making treatment option for patients with severe heart failure; however, the patients occasionally experience severe acute ischemic strokes (AISs). Although mechanical thrombectomy is considered as an effective treatment for severe AIS in patients with LVADs, there remains a paucity of data on the long-term outcomes. This study aimed to investigate the acute-phase efficacy and long-term outcomes of mechanical thrombectomy for AIS patients with LVADs.

METHODS

We retrospectively reviewed 9 cases in 8 patients with LVADs who developed AIS and underwent mechanical thrombectomy from July 2014 to November 2021 at our hospital. Clinical information, including the National Institutes of Health Stroke Scale score and modified Rankin Scale score before and after thrombectomy, the details of procedures, and the long-term outcomes after thrombectomy, was retrospectively reviewed and statistically analyzed.

RESULTS

Effective recanalization was achieved in 89% of the 9 cases. The median National Institutes of Health Stroke Scale score improved from 12 (range, 8-29) to 5 (range, 0-29) after mechanical thrombectomy. The median total follow-up duration was 1327 (range, 78-2659) days. Of the 8 patients, 3 patients underwent heart transplantation, and the LVAD was removed after recovery of the patient's heart function. One patient awaited heart transplantation.

CONCLUSIONS

This study revealed the long-term benefit of mechanical thrombectomy for AIS in patients with LVADs, eventually achieving 50% of independence from LVADs.

The CHA2DS2-VASc risk score predicts successful endovascular treatment in patients with acute ischemic stroke

OBJECTIVES

Acute ischemic stroke is a common cause of mortality and morbidity worldwide. Percutaneous endovascular intervention is an important treatment method in ischemic stroke. Endovascular procedure success is associated with the clinical outcome of the patients. The CHA2DS2-VASC score is an important score used to determine the risk of ischemic stroke in patients with atrial fibrillation. In our study, we aimed to evaluate the relationship between procedure success and CHA2DS2-VASC score in patients with acute ischemic stroke who underwent endovascular intervention.

MATERIALS AND METHODS

A total of 102 consecutive patients who underwent endovascular intervention with acute ischemic stroke were included in the study. The admission CHA2DS2-VASc scores of the patients were recorded. After the procedure, the relationship between the TICI score and the CHA2DS2-VASc score was evaluated.

RESULTS

CHA2DS2-VASc score was significantly higher in the group that resulted in unsuccessful endovascular intervention (2.78 ± 1.44, 5.02 ± 1.77 p < .001). Receiver-operating characteristics analysis revealed the cutoff value of CHA2DS2-VASc score ≥3 as a predictor of unsuccessful intervention with 76,6% sensitivity and 83,3% specificity, positive predictive value 50%, negative predictive value 84,6% (area under the curve [AUC]: 0.827,95% CI: 0.739-0.895, p < .001). In the multivariate analysis; atrial fibrillation ([β] = 4.201; [CI]: 1.251-14.103, p = .020), CHA2DS2-VASc score ([β] = 0.053; [CI]: 0.004-0.750, p = .030) were found independent predictors for unsuccessful intervention treatment.

CONCLUSIONS

In our study, we showed that the CHA2DS2-VASc score is associated with the success of endovascular intervention in patients with acute ischemic stroke who underwent percutaneous endovascular treatment.

Multimodal recanalization for subacute symptomatic internal carotid artery occlusion due to atherosclerosis: Outcomes and notes on hybrid techniques

OBJECTIVES

Subacute internal carotid artery occlusion (ICAO) is associated with ipsilateral recurrent stroke, and successful recanalization of ICAO can improve cerebral blood perfusion (CBP) and prevent stroke. However, the optimal treatment remains controversial.

METHODS

We conducted a retrospective analysis of patients with subacute symptomatic ICAO due to atherosclerosis treated at our center. The hybrid surgical procedures included carotid endarterectomy, Fogarty balloon catheter embolectomy, aspiration thrombectomy and percutaneous transluminal angioplasty/stenting. Recanalization rates, CBP improvement, stroke recurrence and restenosis/reocclusion were investigated.

RESULTS

Fourteen symptomatic atherosclerotic ICAO patients (type A, 4; type C, 10; men, 11; women, 3; average age, 68.1 ± 7.9 years) in the subacute phase were treated with a multimodal recanalization technique. Symptoms included mild cerebral infarction, transient ischemic attack (TIA) and amaurosis fugax. The average onset-to-treatment time was 18.1 ± 4.8 days. The successful recanalization (thrombolysis in cerebral ischemia grade 2 or 3) rate was 100%. The ipsilateral-to-contralateral mean transit time ratio was significantly lower at the 1-year follow-up than preoperatively (1.01 ± 0.05 vs. 1.26 ± 0.09, P < 0.0001). There was one case of restenosis detected 1 year after surgery and no cases of reocclusion. During the 28.3 ± 10.0 months of follow-up, only 2 cases of TIA occurred. The average modified Rankin Scale score and National Institute of Health Stroke Scale score were significantly lower at themost recent follow-up than before recanalization (1.21 ± 0.89 vs. 1.86 ± 0.66, P = 0.0003; 1.36 ± 1.55 vs. 2.00 ± 1.88, P = 0.0066).

CONCLUSION

Multimodal recanalization techniques performed in a hybrid operation theater can safely achieve high recanalization rates in atherosclerotic ICAO patients in the subacute phase, which can be beneficial for recovering CBP and preventing stroke.

Efficacy and safety of electroacupuncture for post-stroke depression: a randomized controlled trial

OBJECTIVE

The objective of this study is to evaluate the efficacy and safety of electroacupuncture (EA) treatment for post-stroke depression (PSD).

METHODS

This study was a single-center, single-blinded, parallel-arm randomized controlled trial. In total, 65 patients with PSD were randomly allocated into EA and sham EA groups. Treatment was administered at GV20, Sishencong, SP6, LR3 and BL18 in both groups. The EA group received EA treatment, while the sham EA group received sham EA treatment using the Park device. Treatment was given three times a week for 4 weeks. The primary outcome was the Hamilton Rating Scale for Depression (HRSD). Secondary outcomes included the Zung Self-Rating Depression Scale (SDS), National Institutes of Health Stroke Scale (NIHSS), Barthel Daily Living Index (BI) and depression scale of traditional Chinese medicine (TCM). Primary and secondary outcomes were assessed at baseline, week 2 after treatment, week 4 after treatment and week 8 of follow-up. Safety assessment was conducted at each visit for 4 weeks of treatment.

RESULTS

Significant differences in HRSD, SDS, NIHSS, BI and TCM scale scores were found in the EA group before and after acupuncture treatment (all p < 0.001). Compared with the sham EA group, HRSD scores improved significantly in the EA group at the end of week 2 (F = 31.33, p < 0.001), week 4 (F = 35.58, p < 0.001) and week 8 after treatment onset (F = 25.03, p < 0.001). Similarly, significant improvements were observed in SDS, NIHSS and BI scores. Two participants in the EA group suffered a local hematoma, while no adverse events were reported in the sham EA group.

CONCLUSION

EA appears to be an efficacious and safe treatment for PSD. According to our results, EA may alleviate depressive symptoms, and improve neurological function and capabilities with respect to activities of daily living (ADLs).

TRIAL REGISTRATION NUMBER

ChiCTR-IOR-17012610 (Chinese Clinical Trial Registry).

Successful mechanical thrombectomy in acute ischemic stroke: revascularization grade and functional independence

Most studies define the technical success of endovascular thrombectomy (EVT) as a Thrombolysis in Cerebral Infarction (TICI) revascularization grade of 2b or higher. However, growing evidence suggests that TICI 3 is the best angiographic predictor of improved functional outcomes. To assess the association between successful TICI revascularization grades and functional independence at 90 days, we performed a systematic review and network meta-analysis of thrombectomy studies that reported TICI scores and functional outcomes, measured by the modified Rankin Scale, using the semi-automated AutoLit software platform. Forty studies with 8691 patients were included in the quantitative synthesis. Across TICI, modified TICI (mTICI), and expanded TICI (eTICI), the highest rate of good functional outcomes was observed in patients with TICI 3 recanalization, followed by those with TICI 2c and TICI 2b recanalization, respectively. Rates of good functional outcomes were similar among patients with either TICI 2c or TICI 3 grades. On further sensitivity analysis of the eTICI scale, the rates of good functional outcomes were equivalent between eTICI 2b50 and eTICI 2b67 (OR 0.81, 95% CI 0.52 to 1.25). We conclude that near complete or complete revascularization (TICI 2c/3) is associated with higher rates of functional outcomes after EVT.

Relationship Between Body Temperature and Early Neurological Deterioration after Endovascular Thrombectomy for Acute Ischemic Stroke with Large Vessel Occlusion

BACKGROUND

Early neurological deterioration (END) after endovascular thrombectomy (EVT) is strongly associated with poor prognosis in patients with large vessel occlusion. The relationship between body temperature and END after EVT is unknown, which we aimed to investigate in this study.

METHODS

END was defined as an increase of four or more points on the National Institutes of Health Stroke Scale score compared with the baseline assessment within 24 h. Logistic regression and restricted cubic spline models were used to assess the relationship between body temperature and END.

RESULTS

Among 7741 consecutive patients with ischemic stroke, 406 patients with large vessel occlusion who underwent EVT were enrolled. In total, 88 (21.7%) patients developed END. Logistic regression showed that the maximum body temperature within 24 h (odds ratio [OR] = 1.97 per °C, 95% confidence interval [CI] 1.17-3.32, p = 0.010) was independently associated with END. This association was nonlinear and J shaped (p for nonlinearity = 0.010), and the risk of END increased when the maximum body temperature within 24 h was lower or higher than 37.0 °C. Fever burden is also independently associated with END (OR = 1.06 per °C  × hour, 95% CI 1.01-1.11, p = 0.012). In addition, the timing of fever onset was independently associated with END, and the highest risk of END was associated with fever onset within 6 h after EVT (OR = 3.92, 95% CI 1.25-12.27, p = 0.019).

CONCLUSIONS

In summary, there is a J-shaped association between the maximum body temperature within 24 h after EVT and END. Moreover, the risk of END differed according to the timing of fever onset.

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.

Deep Learning-Based Automated Thrombolysis in Cerebral Infarction Scoring: A Timely Proof-of-Principle Study

Background and Purpose

Mechanical thrombectomy is an established procedure for treatment of acute ischemic stroke. Mechanical thrombectomy success is commonly assessed by the Thrombolysis in Cerebral Infarction (TICI) score, assigned by visual inspection of X-ray digital subtraction angiography data. However, expert-based TICI scoring is highly observer-dependent. This represents a major obstacle for mechanical thrombectomy outcome comparison in, for instance, multicentric clinical studies. Focusing on occlusions of the M1 segment of the middle cerebral artery, the present study aimed to develop a deep learning (DL) solution to automated and, therefore, objective TICI scoring, to evaluate the agreement of DL- and expert-based scoring, and to compare corresponding numbers to published scoring variability of clinical experts.

Methods

The study comprises 2 independent datasets. For DL system training and initial evaluation, an in-house dataset of 491 digital subtraction angiography series and modified TICI scores of 236 patients with M1 occlusions was collected. To test the model generalization capability, an independent external dataset with 95 digital subtraction angiography series was analyzed. Characteristics of the DL system were modeling TICI scoring as ordinal regression, explicit consideration of the temporal image information, integration of physiological knowledge, and modeling of inherent TICI scoring uncertainties.

Results

For the in-house dataset, the DL system yields Cohen’s kappa, overall accuracy, and specific agreement values of 0.61, 71%, and 63% to 84%, respectively, compared with the gold standard: the expert rating. Values slightly drop to 0.52/64%/43% to 87% when the model is, without changes, applied to the external dataset. After model updating, they increase to 0.65/74%/60% to 90%. Literature Cohen’s kappa values for expert-based TICI scoring agreement are in the order of 0.6.

Conclusions

The agreement of DL- and expert-based modified TICI scores in the range of published interobserver variability of clinical experts highlights the potential of the proposed DL solution to automated TICI scoring.

Factors Associated With Decreased Accuracy of Modified Thrombolysis in Cerebral Infarct Scoring Among Neurointerventionalists During Thrombectomy

Background and Purpose

The modified Thrombolysis in Cerebral Infarct (mTICI) score is used to grade angiographic outcome after endovascular thrombectomy. We sought to identify factors that decrease the accuracy of intraprocedural mTICI.

Methods

We performed a 2-center retrospective cohort study comparing operator (n=6) mTICI scores to consensus scores from blinded adjudicators. Groups were also assessed by dichotomizing mTICI scores to 0–2a versus 2b–3.

Results

One hundred thirty endovascular thrombectomy procedures were included. Operators and adjudicators had a pairwise agreement in 96 cases (73.8%). Krippendorff α was 0.712. Multivariate analysis showed endovascular thrombectomy overnight (odds ratio [OR]=3.84 [95% CI, 1.22–12.1]), lacking frontal (OR, 5.66 [95 CI, 1.36–23.6]), or occipital (OR, 7.18 [95 CI, 2.12–24.3]) region reperfusion, and higher operator mTICI scores (OR, 2.16 [95 CI, 1.16–4.01]) were predictive of incorrectly scoring mTICI intraprocedurally. With dichotomized mTICI scores, increasing number of passes was associated with increased risk of operator error (OR, 1.93 [95 CI, 1.22–3.05]).

Conclusions

In our study, mTICI disagreement between operator and adjudicators was observed in 26.2% of cases. Interventions that took place between 22:30 and 4:00, featured frontal or occipital region nonperfusion, higher operator mTICI scores, and increased number of passes had higher odds of intraprocedural mTICI inaccuracy.

autoTICI: Automatic Brain Tissue Reperfusion Scoring on 2D DSA Images of Acute Ischemic Stroke Patients

The Thrombolysis in Cerebral Infarction (TICI) score is an important metric for reperfusion therapy assessment in acute ischemic stroke. It is commonly used as a technical outcome measure after endovascular treatment (EVT). Existing TICI scores are defined in coarse ordinal grades based on visual inspection, leading to inter- and intra-observer variation. In this work, we present autoTICI, an automatic and quantitative TICI scoring method. First, each digital subtraction angiography (DSA) acquisition is separated into four phases (non-contrast, arterial, parenchymal and venous phase) using a multi-path convolutional neural network (CNN), which exploits spatio-temporal features. The network also incorporates sequence level label dependencies in the form of a state-transition matrix. Next, a minimum intensity map (MINIP) is computed using the motion corrected arterial and parenchymal frames. On the MINIP image, vessel, perfusion and background pixels are segmented. Finally, we quantify the autoTICI score as the ratio of reperfused pixels after EVT. On a routinely acquired multi-center dataset, the proposed autoTICI shows good correlation with the extended TICI (eTICI) reference with an average area under the curve (AUC) score of 0.81. The AUC score is 0.90 with respect to the dichotomized eTICI. In terms of clinical outcome prediction, we demonstrate that autoTICI is overall comparable to eTICI.

Endovascular therapy in patients with large vessel occlusion due to cardioembolism versus large-artery atherosclerosis

Background and aims:

To investigate whether stroke aetiology affects outcome in patients with acute ischaemic stroke who undergo endovascular therapy.

Methods:

We retrospectively analysed patients from the Bernese Stroke Centre Registry (January 2010–September 2018), with acute large vessel occlusion in the anterior circulation due to cardioembolism or large-artery atherosclerosis, treated with endovascular therapy (±intravenous thrombolysis).

Results:

The study included 850 patients (median age 77.4 years, 49.3% female, 80.1% with cardioembolism). Compared with those with large-artery atherosclerosis, patients with cardioembolism were older, more often female, and more likely to have a history of hypercholesterolaemia, atrial fibrillation, current smoking (each p < 0.0001) and higher median National Institutes of Health Stroke Scale (NIHSS) scores on admission (p = 0.030). They were more frequently treated with stent retrievers (p = 0.007), but the median number of stent retriever attempts was lower (p = 0.016) and fewer had permanent stent placements (p ⩽ 0.004). Univariable analysis showed that patients with cardioembolism had worse 3-month survival [72.7% versus 84%, odds ratio (OR) = 0.51; p = 0.004] and modified Rankin scale (mRS) score shift (p = 0.043) and higher rates of post-interventional heart failure (33.5% versus 18.5%, OR = 2.22; p < 0.0001), but better modified thrombolysis in cerebral infarction (mTICI) score shift (p = 0.025). Excellent (mRS = 0–1) 3-month outcome, successful reperfusion (mTICI = 2b–3), symptomatic intracranial haemorrhage and Updated Charlson Comorbidity Index were similar between groups. Propensity-matched analysis found no statistically significant difference in outcome between stroke aetiology groups. Stroke aetiology was not an independent predictor of favourable mRS score shift, but lower admission NIHSS score, younger age and independence pre-stroke were (each p < 0.0001). Stroke aetiology was not an independent predictor of heart failure, but older age, admission antithrombotics and dependence pre-stroke were (each ⩽0.027). Stroke aetiology was not an independent predictor of favourable mTICI score shift, but application of stent retriever and no permanent intracranial stent placement were (each ⩽0.044).

Conclusion:

We suggest prospective studies to further elucidate differences in reperfusion and outcome between patients with cardioembolism and large-artery atherosclerosis.

Good Clinical Outcome Decreases With Number of Retrieval Attempts in Stroke Thrombectomy: Beyond the First-Pass Effect

Supplemental Digital Content is available in the text.

Background and Purpose:

Endovascular therapy is the standard of care in the treatment of acute ischemic stroke due to large-vessel occlusion. Often, more than one retrieval attempt is needed to achieve reperfusion. We aimed to quantify the influence of endovascular therapy on clinical outcome depending on the number of retrievals needed for successful reperfusion in a large multi-center cohort.

Methods:

For this observational cohort study, 2611 patients from the prospective German Stroke Registry included between June 2015 and April 2018 were analyzed. Patients who received endovascular therapy for acute anterior circulation stroke with known admission National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score, final Thrombolysis in Cerebral Infarction score, and number of retrievals were included. Successful reperfusion was defined as a Thrombolysis in Cerebral Infarction score of 2b or 3. The primary outcome was defined as functional independence (modified Rankin Scale score of 0–2) at day 90. Multivariate mixed-effects models were used to adjust for cluster effects of the participating centers and confounders.

Results:

The inclusion criteria were met by 1225 patients. The odds of good clinical outcome decreased with every retrieval attempt required for successful reperfusion: the first retrieval had the highest odds of good clinical outcome (adjusted odds ratio, 6.45 [95% CI, 4.0–10.4]), followed by the second attempt (adjusted odds ratio, 4.56 [95% CI, 2.7–7.7]), and finally the third (adjusted odds ratio, 3.16 [95% CI, 1.8–5.6]).

Conclusions:

Successful reperfusion within the first 3 retrieval attempts is associated with improved clinical outcome compared with patients without reperfusion. We conclude that at least 3 retrieval attempts should be performed in endovascular therapy of anterior circulation strokes.

Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03356392.

Biomechanics and hemodynamics of stent-retrievers

In 2015, multiple randomized clinical trials showed an unparalleled treatment benefit of stent-retriever thrombectomy as compared to standard medical therapy for the treatment of a large artery occlusion causing acute ischemic stroke. A short time later, the HERMES collaborators presented the patient-level pooled analysis of five randomized clinical trials, establishing class 1, level of evidence A for stent-retriever thrombectomy, in combination with intravenous thrombolysis when indicated to treat ischemic stroke. In the years following, evidence continues to mount for expanded use of this therapy for a broader category of patients. The enabling technology that changed the tide to support endovascular treatment of acute ischemic stroke is the stent-retriever. This review summarizes the history of intra-arterial treatment of stroke, introduces the biomechanics of embolus extraction with stent-retrievers, describes technical aspects of the intervention, provides a description of hemodynamic implications of stent-retriever embolectomy, and proposes future directions for a more comprehensive, multi-modal endovascular approach for the treatment of acute ischemic stroke.

Reliability of the Modified TICI Score among Endovascular Neurosurgeons

BACKGROUND AND PURPOSE

The modified TICI score is the benchmark for quantifying reperfusion after mechanical thrombectomy. There has been limited investigation into the reliability of this score. We aim to identify intra-rater and inter-rater reliability of the mTICI score among endovascular neurosurgeons.

MATERIALS AND METHODS

Four independent endovascular neurosurgeons (raters) reviewed angiograms of 67 patients at 2 time points. κ statistics assessed inter- and intrarater reliability and compared raters'-versus-proceduralists' scores. Reliability was also assessed for occlusion location and by dichotomizing modified TICI scores (0-2a versus 2b-3).

RESULTS

Interrater reliability was moderate-to-substantial, weighted κ = 0.417-0.703, overall κ = 0.374 (P < .001). The dichotomized modified TICI score had moderate-to-substantial interrater agreement, κ statistics = 0.468-0.715, overall κ = 0.582 (P < .001). Intrarater reliability was moderate-to-almost perfect, weighted κ = 0.594-0.81. The dichotomized modified TICI score had substantial-to-almost perfect reliability, κ = 0.632-0.82. Proceduralists had fair-to-moderate agreement with raters, weighted κ = 0.348-0.574, and the dichotomized modified TICI score had fair-to-moderate agreement, κ = 0.365-0.544. When proceduralists and raters disagreed, proceduralists' scores were higher in 79.6% of cases. M1 followed by ICA occlusions had the highest agreement.

CONCLUSIONS

The modified TICI score is a practical metric for assessing reperfusion after mechanical thrombectomy, though not without limitations. Agreement improved when scores were dichotomized around the clinically relevant threshold of successful revascularization. Interrater reliability improved with time, suggesting that formal training of interventionalists may improve reporting reliability. Agreement of the modified TICI scale is best with M1 and ICA occlusion and becomes less reliable with more distal or posterior circulation occlusions. These findings should be considered when developing research trials.

qTICI: Quantitative assessment of brain tissue reperfusion on digital subtraction angiograms of acute ischemic stroke patients

BACKGROUND

The Thrombolysis in Cerebral Infarction (TICI) scale is an important outcome measure to evaluate the quality of endovascular stroke therapy. The TICI scale is ordinal and observer-dependent, which may result in suboptimal prediction of patient outcome and inconsistent reperfusion grading.

AIMS

We present a semi-automated quantitative reperfusion measure (quantified TICI (qTICI)) using image processing techniques based on the TICI methodology.

METHODS

We included patients with an intracranial proximal large vessel occlusion with complete, good quality runs of anteroposterior and lateral digital subtraction angiography from the MR CLEAN Registry. For each vessel occlusion, we identified the target downstream territory and automatically segmented the reperfused area in the target downstream territory on final digital subtraction angiography. qTICI was defined as the percentage of reperfused area in target downstream territory. The value of qTICI and extended TICI (eTICI) in predicting favorable functional outcome (modified Rankin Scale 0-2) was compared using area under receiver operating characteristics curve and binary logistic regression analysis unadjusted and adjusted for known prognostic factors.

RESULTS

In total, 408 patients with M1 or internal carotid artery occlusion were included. The median qTICI was 78 (interquartile range 58-88) and 215 patients (53%) had an eTICI of 2C or higher. qTICI was comparable to eTICI in predicting favorable outcome with area under receiver operating characteristics curve of 0.63 vs. 0.62 (P = 0.8) and 0.87 vs. 0.86 (P = 0.87), for the unadjusted and adjusted analysis, respectively. In the adjusted regression analyses, both qTICI and eTICI were independently associated with functional outcome.

CONCLUSION

qTICI provides a quantitative measure of reperfusion with similar prognostic value for functional outcome to eTICI score.

Endovascular Thrombectomy of Calcified Emboli in Acute Ischemic Stroke: A Multicenter Study

BACKGROUND AND PURPOSE

Large intracranial vessel occlusion due to calcified emboli is a rare cause of major stroke. We assessed the prevalence, imaging appearance, the effectiveness of mechanical thrombectomy, and clinical outcome of patients with large-vessel occlusion due to calcified emboli.

MATERIALS AND METHODS

We performed a retrospective analysis of clinical and procedural data of consecutive patients who underwent mechanical thrombectomy due to calcified emboli in 7 European stroke centers.

RESULTS

We screened 2969 patients, and 40 patients matched the inclusion criteria, accounting for a prevalence of 1.3%. The mean maximal density of the thrombus was 327 HU (range, 150-1200 HU), and the mean thrombus length was 9.2 mm (range, 4-20 mm). Four patients had multiple calcified emboli, and 2 patients had an embolic event during an endovascular intervention. A modified TICI score of ≥2b was achieved in 57.5% (23/40), with minimal-to-no reperfusion (modified TICI 0-1) in 32.5% (13/40) and incomplete reperfusion (modified TICI 2a) in 10% (4/40). Excellent outcome (mRS 0-1) was achieved in only 20.6%, functional independence (mRS 0-2) in 26.5% and 90-day mortality was 55.9%.

CONCLUSIONS

Acute ischemic stroke with large-vessel occlusion due to calcified emboli is a rare entity in patients undergoing thrombectomy, with considerably worse angiographic outcome and a higher mortality compared with patients with noncalcified thrombi. Good functional recovery at 3 months can still be achieved in about a quarter of patients.

Operator Versus Core Lab Adjudication of Reperfusion After Endovascular Treatment of Acute Ischemic Stroke

Background and Purpose- The modified Treatment In Cerebral Ischemia (mTICI) score is the standard method to quantify the degree of reperfusion after endovascular treatment in acute ischemic stroke. In clinical practice, it is commonly assessed by local operators after the procedure. In clinical trials and registries, mTICI is evaluated by an imaging core lab. The aim of this study was to compare operator mTICI with core lab mTICI scores in patients included in the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry. Methods- All patients with an intracranial carotid or middle cerebral artery occlusion with anteroposterior and lateral digital subtraction angiography runs were included. Operators determined the mTICI score immediately after endovascular treatment. Core lab neuroradiologists were blinded to clinical characteristics and assessed mTICI scores based on pre- and postintervention digital subtraction angiography. The agreement between operator and core lab mTICI scores and their value in the prediction of outcome (score on modified Rankin Scale at 90 days) was determined. Results- In total, 1130 patients were included. The proportion of agreement between operator and core lab mTICI score was 56% (95% CI, 54%-59%). In 33% (95% CI, 31%-36%), mTICI was overestimated by operators. Operators reported a higher rate of successful reperfusion than the core lab (77% versus 67%; difference 10% [95% CI, 6%-14%]; P<0.001). In 252 (33%) of 763 patients scored as incomplete reperfusion by the core lab (mTICI <3), the local read was mTICI 3. Multivariable logistic regression models containing either core lab scored or operator scored successful reperfusion predicted outcome on the full (C statistic of both models: 0.76) or dichotomized modified Rankin Scale (modified Rankin Scale, 0-2; C statistic of both models: 0.83) equally well. Conclusions- Operators tend to overestimate the degree of reperfusion compared with the core lab although this does not affect the accuracy of outcome prediction.

Efficacy and safety of direct aspiration versus stent-retriever for recanalization in acute cerebral infarction: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND AND PURPOSE

Whether the direct aspiration approach of thrombectomy for recanalization in patients with acute ischemic stroke has a similar efficacy and safety compared to the stent-retriever remains uncertain.

METHODS

We conducted a meta-analysis of 9 studies obtained through PubMed and Embase database searches to determine whether successful recanalization rate, good functional outcome at 3 months (modified Rankin score, mRS≤2), procedure time from groin puncture to maximal revascularization and procedure-related adverse events differed between patients who underwent the direct aspiration and those receiving stent-retriever for recanalization in acute cerebral infarction.

RESULTS

There was no significant difference between the direct aspiration group and the stent-retriever group in rate of successful recanalization (summary odds ratio [OR], 0.86 [95% confidence interval (CI), 0.45-1.52]; P = .60), but a better functional outcomes in the direct aspiration group at 3 months defined as a mRS score of 0 to 2 (OR, 0.77; 95% CI, 0.66-0.97; P = .03). Furthermore, the direct aspiration patients compared with the stent-retriever patients had a tendency of shorter procedural time (Mean difference [MD], -8.77 [95% CI, from-18.90 to 1.37]; P = .09). Finally, there were less adverse events especially in symptomatic intracerebral hemorrhage (sICH) (OR, 0.56; 95% CI, 0.33-0.98; P = .04) and embolization to a new territory (ENT) (OR, 0.49; 95% CI, 0.28-0.84; P = .01) in the direct aspiration group when compared with the stent-retriever group, although no difference between them in the rate of any ICH (OR, 0.81; 95% CI, 0.41-1.60; P = .54).

CONCLUSIONS

The results support that the direct aspiration technique for those acute ischemic stroke patients may have better functional outcomes, less procedure related-adverse events and a tendency of faster revascularization time as compared to the stent-retriever thrombectomy, with a similar successful recanalization rate. However, major limitations of current evidence (mainly from retrospective and observational studies and a small number of patients population) indicate a need for adequately powered, multicenter randomized controlled trials (RCT) to answer this question.

Systematic review and meta-analysis on outcome differences among patients with TICI2b versus TICI3 reperfusions: success revisited

OBJECTIVE

A reperfusion quality of thrombolysis in cerebral infarction (TICI)≥2b has been set as the therapeutic angiography target for interventions in patients with acute ischaemic stroke. This study addresses whether the distinction between TICI2b and TICI3 reperfusions shows a clinically relevant difference on functional outcome.

METHODS

A systematic literature review and meta-analysis was carried out and presented in conformity with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria to test the primary hypothesis that TICI2b and TICI3 reperfusions are associated with different rates of modified Rankin Scale (mRS) ≤2 at day 90. Secondary endpoints included rates of haemorrhagic transformations, mortality and excellent functional outcome (mRS ≤1). Summary estimates of ORs (sOR) with 95% CI were calculated using the inverse variance heterogeneity model accounting for multiple true effect sizes.

RESULTS

Fourteen studies on 2379 successfully reperfused patients were included (1131 TICI3, 1248 TICI2b). TICI3 reperfusions were associated with higher rates of functional independence (1.74, 95% CI 1.44 to 2.10) and excellent functional outcomes (2.01, 95% CI 1.60 to 2.53), also after including adjusted estimates. The safety profile of patients with TICI3 was superior, as demonstrated by lower rates of mortality (sOR 0.59, 95% CI 0.37 to 0.92) and symptomatic intracranial haemorrhages (sOR 0.42, 95% CI 0.25 to 0.71).

CONCLUSION

TICI3 reperfusions are associated with superior outcome and better safety profiles than TICI2b reperfusions. This effect seems to be independent of time and collaterals. As reperfusion quality is the most important modifiable predictor of patients' outcome, a more conservative definition of successful therapy and further evaluation of treatment approaches geared towards achieving TICI3 reperfusions are desirable.

Predictive values of CSS and NIHSS in the prognosis of patients with acute cerebral infarction: A comparative analysis

This study aims to investigate the predictive values of the Chinese Stroke Scale (CSS) and National Institutes of Health Stroke Scale (NIHSS) in the prognosis of patients with acute cerebral infarction.A total of 399 patients with acute cerebral infarction were assessed using CSS and NIHSS within 1 day after admission. Then, the receiver operating characteristic (ROC) curves were established, and the area under the curves of these 2 scoring systems was compared.The area under the curve of CSS and NIHSS was 0.796 and 0.794, respectively.CSS and NIHSS have good predictive values for the prognosis of patients with acute cerebral infarction.

2D Parametric Parenchymal Blood Flow as a Predictor of the Hemorrhagic Events after Endovascular Treatment of Acute Ischemic Stroke: A Single-Center Retrospective Study

Background and Purpose

Intracranial hemorrhage (ICH) is one of the major adverse events related to the endovascular management of acute ischemic stroke. It is important to evaluate the risk of ICH as it may result in clinical deterioration of the patients. Development of tools which can predict the risk of ICH after thrombectomy can reduce the procedure-related morbidity and mortality. 2D parenchymal blood flow could potentially act as an indicator for ICH.

Methods

2D parenchymal blood flow was used to evaluate pre- and postthrombectomy digital subtraction angiography series of patients with acute ischemic stroke in the anterior circulation. A recently developed software allows the separation of the vascular filling and parenchymal blush signals using band-pass and band-reject filtering to allow for greater visibility of the parenchyma offering a better visual indicator of the effect of treatment. The "wash-in rate" was selected as the parameter of interest to predict ICH.

Results

According to the presence or absence of signs of intracranial parenchymal hemorrhage in the follow-up dual-energy CT brain scans, the patients were classified into a hemorrhagic and nonhemorrhagic group (15 patients each). The only significant difference between the groups is the calculated wash-in rate after thrombectomy (p = 0.024). The cutoff value of the wash-in rate after thrombectomy was suggested to be 11,925.0, with 60% sensitivity to predict the hemorrhage and 93.3% specificity.

Conclusions

Elevated parametric parenchymal blood flow wash-in rates after thrombectomy may be associated with increased risk of hemorrhagic events.

Monitoring cerebral blood flow change through use of arterial spin labelling in acute ischaemic stroke patients after intra-arterial thrombectomy

OBJECTIVES

To evaluate the ability of arterial spin labelling perfusion-weighted imaging (ASL-PWI) to identify reperfusion status and to predict the early neurological outcome of acute ischaemic stroke patients after intra-arterial (IA) thrombectomy.

METHODS

A total of 51 acute ischaemic stroke patients who underwent IA thrombectomy were retrospectively reviewed. Asymmetrical index before and after IA thrombectomy (AICBF_pre and AICBF_post) and volume ratio of the reperfused territory to the baseline perfusion abnormality (reperfusion volume ratio) were calculated on ASL-PWI. A paired t-test was used to compare AICBF_pre and AICBF_post. Pearson correlation and multiple linear regression were performed to evaluate correlations between the imaging parameters and NIHSS scores.

RESULTS

Mean AICBF_post was significantly higher than mean AICBF_pre (0.923±0.352 vs. 0.312±0.191, p<0.001). AICBF_pre had a significant correlation with NIHSS_pre (pr=-0.430, p=.004). ∆AICBF had significant correlations with NIHSS_{24 h}, NIHSS_{5-7 days} and ∆NIHSS_{5-7 days} (r=-0.356, p=0.028; r=-0.597, p<0.001; r=-0.346, p=0.033, respectively). ∆AICBF, reperfusion volume ratio and baseline infarct volume were significant independent predictors for NIHSS_{5-7 days}.

CONCLUSIONS

ASL-PWI has the potential to serve as a non-invasive imaging tool to monitor the reperfusion status and predict the early neurological outcome of acute ischaemic stroke patients after IA thrombectomy.

KEY POINTS

• CBF change on ASL-PWI after IA thrombectomy correlated with NIHSS scores. • ASL-PWI can non-invasively monitor reperfusion in AIS patients after IA thrombectomy. • ASL-PWI may predict early outcome of AIS patients after IA thrombectomy.

Effectiveness and Safety of Mechanical Thrombectomy with Stent Retrievers in Basilar Artery Occlusion: Comparison with Anterior Circulation Occlusions

Objective

Acute basilar artery occlusion (BAO) is associated with severe neurological dysfunction and high mortality rates. The benefits of mechanical thrombectomy in BAO have not been explored in recent clinical trials. Therefore, we analyzed outcomes of stent retriever mechanical thrombectomy for BAO, and compared with anterior circulation occlusions (ACO).

Methods

In total, 161 consecutive patients (24 BAO, 137 ACO) who underwent mechanical thrombectomy with the stent retriever between January 2013 and August 2016 enrolled in our study. All patients underwent clinical assessment with the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS). Radiological results were used to evaluate thrombolysis in cerebral infarction (TICI) scores and successful recanalization was defined by TICI 2b or 3.

Results

Mean NIHSS scores at 24 hours and 30 days were significantly higher in the BAO group than the ACO group (p=0.021, p=0.001). mRS at 90 days was significantly higher in the BAO group (4.2) compared with the ACO group (3.0) (p=0.003). The BAO group (2.0) performed fewer stent retriever passages than the ACO group (2.7) (p=0.049). There were no significant differences between the two groups in terms of complications, but the BAO patients experienced a higher mortality (16.6%) rate than ACO patients (5.8%) (p=0.001). In subgroup analysis of BAO, patients with short procedure times achieved successful recanalization (p=0.001) and successfully recanalized patients exhibited more favorable mRS at 90 days (p=0.027).

Conclusion

In our study, mechanical thrombectomy of BAO patients showed worse clinical outcome and higher mortality rate than ACO patients. However, mechanical thrombectomy with a stent retriever in BAO is an effective treatment, because successfully recanalized patients showed good clinical outcome in BAO patients.

Impact of Smartphone Applications on Timing of Endovascular Therapy for Ischemic Stroke: A Preliminary Study

BACKGROUND

The metrics of imaging-to-puncture and imaging-to-reperfusion were recently found to be associated with the clinical outcomes of endovascular thrombectomy for acute ischemic stroke. However, measures for improving workflow within hospitals to achieve better timing results are largely unexplored for endovascular therapy. The aim of this study was to examine our experience with a novel smartphone application developed in house to improve our timing metrics for endovascular treatment.

METHODS

We developed an encrypted smartphone application connecting all stroke team members to expedite conversations and to provide synchronized real-time updates on the time window from stroke onset to imaging and to puncture. The effects of the application on the timing of endovascular therapy were evaluated with a secondary analysis of our single-center cohort. Our primary outcome was imaging-to-puncture time. We assessed the outcomes with nonparametric tests of statistical significance.

RESULTS

Forty-five patients met our criteria for analysis among 66 consecutive patients with acute ischemic stroke who received endovascular therapy at our institution. After the implementation of the smartphone application, imaging-to-puncture time was significantly reduced (preapplication median time, 127 minutes; postapplication time, 69 minutes; P < 0.001). Puncture-to-reperfusion time was not affected by the application use (42 minutes vs. 36 minutes).

CONCLUSION

The use of smartphone applications may reduce treatment times for endovascular therapy in acute ischemic stroke. Further studies are needed to confirm our findings.

Effect of Endovascular Contact Aspiration vs Stent Retriever on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion: The ASTER Randomized Clinical Trial

Importance

The benefits of endovascular revascularization using the contact aspiration technique vs the stent retriever technique in patients with acute ischemic stroke remain uncertain because of lack of evidence from randomized trials.

Objective

To compare efficacy and adverse events using the contact aspiration technique vs the standard stent retriever technique as a first-line endovascular treatment for successful revascularization among patients with acute ischemic stroke and large vessel occlusion.

Design, Setting, and Participants

The Contact Aspiration vs Stent Retriever for Successful Revascularization (ASTER) study was a randomized, open-label, blinded end-point clinical trial conducted in 8 comprehensive stroke centers in France (October 2015-October 2016). Patients who presented with acute ischemic stroke and a large vessel occlusion in the anterior circulation within 6 hours of symptom onset were included.

Interventions

Patients were randomly assigned to first-line contact aspiration (n = 192) or first-line stent retriever (n = 189) immediately prior to mechanical thrombectomy.

Main Outcomes and Measures

The primary outcome was the proportion of patients with successful revascularization defined as a modified Thrombolysis in Cerebral Infarction score of 2b or 3 at the end of all endovascular procedures. Secondary outcomes included degree of disability assessed by overall distribution of the modified Rankin Scale (mRS) score at 90 days, change in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours, all-cause mortality at 90 days, and procedure-related serious adverse events.

Results

Among 381 patients randomized (mean age, 69.9 years; 174 women [45.7%]), 363 (95.3%) completed the trial. Median time from symptom onset to arterial puncture was 227 minutes (interquartile range, 180-280 minutes). For the primary outcome, the proportion of patients with successful revascularization was 85.4% (n = 164) in the contact aspiration group vs 83.1% (n = 157) in the stent retriever group (odds ratio, 1.20 [95% CI, 0.68-2.10]; P = .53; difference, 2.4% [95% CI, -5.4% to 9.7%]). For the clinical efficacy outcomes (change in NIHSS score at 24 hours, mRS score at 90 days) and adverse events, there were no significant differences between groups.

Conclusions and Relevance

Among patients with ischemic stroke in the anterior circulation undergoing thrombectomy, first-line thrombectomy with contact aspiration compared with stent retriever did not result in an increased successful revascularization rate at the end of the procedure.

Trial Registration

clinicaltrials.gov Identifier: NCT02523261.

First-line use of contact aspiration for thrombectomy versus a stent retriever for recanalization in acute cerebral infarction: The randomized ASTER study protocol

Rationale Mechanical thrombectomy with a stent retriever is now the standard of care in anterior circulation ischemic stroke caused by large vessel occlusion. New techniques for mechanical thrombectomy, such as contact aspiration, appear promising to increase reperfusion status and improve clinical outcome. Aim We aim at ascertaining whether contact aspiration is more efficient than the stent retriever as a first-line endovascular procedure. Sample size estimates With a two-sided test (alpha = 5%, power = 90%) and an anticipated rate of spontaneous recanalization and catheterization failures of 15%, we estimate that a sample size of 380 patients will be necessary to detect an absolute difference of 15% in primary outcome (superiority design). Methods and design The ASTER trial is a prospective, randomized, multicenter, controlled, open-label, blinded end-point clinical trial. Patients admitted with suspected ischemic anterior circulation stroke secondary to large vessel occlusion, with onset of symptoms <6 h, will be randomly assigned to contact aspiration or stent retriever in a 1:1 ratio; stratified by center and prior IV thrombolysis. If the assigned treatment technique is not successful after three attempts, another technique will be applied, at the operator's discretion. Study outcomes The primary outcome will be successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3) at the end of the endovascular procedures. Secondary outcome will include successful recanalization after the assigned first-line treatment technique alone, procedural times, the need for a rescue technique, complications and modified Rankin Scale at three months. Discussion No previous head to head randomized trials have directly compared contact aspiration versus stent retriever reperfusion techniques. This prospective trial aims to provide further evidence of benefit of contact aspiration versus stent retriever techniques among patients with ischemic stroke.

Impact of Anesthesia on the Outcome of Acute Ischemic Stroke after Endovascular Treatment with the Solitaire Stent Retriever

BACKGROUND AND PURPOSE

General anesthesia during endovascular treatment of acute ischemic stroke may have an adverse effect on outcome compared with conscious sedation. The aim of this study was to examine the impact of the type of anesthesia on the outcome of patients with acute ischemic stroke treated with the Solitaire stent retriever, accounting for confounding factors.

MATERIALS AND METHODS

Four-hundred one patients with consecutive acute anterior circulation stroke treated with a Solitaire stent retriever were included in this prospective analysis. Outcome was assessed after 3 months by the modified Rankin Scale.

RESULTS

One-hundred thirty-five patients (31%) underwent endovascular treatment with conscious sedation, and 266 patients (69%), with general anesthesia. Patients under general anesthesia had higher NIHSS scores on admission (17 versus 13, P < .001) and more internal carotid artery occlusions (44.6% versus 14.8%, P < .001) than patients under conscious sedation. Other baseline characteristics such as time from symptom onset to the start of endovascular treatment did not differ. Favorable outcome (mRS 0-2) was more frequent with conscious sedation (47.4% versus 32%; OR, 0.773; 95% CI, 0.646-0.925; P = .002) in univariable but not multivariable logistic regression analysis (P = .629). Mortality did not differ (P = .077). Independent predictors of outcome were age (OR, 0.95; 95% CI, 0.933-0.969; P < .001), NIHSS score (OR, 0.894; 95% CI, 0.855-0.933; P < .001), time from symptom onset to the start of endovascular treatment (OR, 0.998; 95% CI, 0.996-0.999; P = .011), diabetes mellitus (OR, 0.544; 95% CI, 0.305-0.927; P = .04), and symptomatic intracerebral hemorrhage (OR, 0.109; 95% CI, 0.028-0.428; P = .002).

CONCLUSIONS

In this single-center study, the anesthetic management during stent retriever thrombectomy with general anesthesia or conscious sedation had no impact on the outcome of patients with large-vessel occlusion in the anterior circulation.

Emergent carotid stenting and intra-arterial abciximab in acute ischemic stroke due to tandem occlusion

OBJECTIVE

Acute occlusions of the extracranial internal carotid artery (ICA) and a major intracranial artery respond poorly to intravenous tissue plasminogen activator (tPA) and present an endovascular challenge. The aim of our study was to retrospectively delineate the feasibility of the combined use of emergent carotid stenting and intra-arterial (IA) Abciximab with intracranial revascularization in the setting of acute ischemic stroke and carotid occlusions at our institution.

METHODS

Eleven patients with complete cervical carotid occlusion with or without concomitant intracranial ICA and/or MCA occlusion were identified from a single center, retrospective review of patients admitted to the Stroke unit. We evaluated all cases for complications of emergent cervical ICA recanalization employing carotid stenting and IA Abciximab.

RESULTS

All patients had complete cervical carotid occlusion with (n = 8) or without (n = 3) concomitant intracranial ICA and/or MCA occlusion. Successful emergent cervical ICA recanalization was achieved in all cases. All patients were administered IA Abciximab (dose range 6-17 mg, average 11.4 mg) immediately following the cervical carotid stenting. There was complete recanalization in all patients with no procedural morbidity or mortality. A single case (1/11, 9%) developed asymptomatic hemorrhagic transformation. Upon discharge, 9 patients (9/11, 82%) had a mRS of 0-2 and 2 patients (2/11, 18%) had a mRS of 3.

CONCLUSIONS

In acute ICA-MCA/distal ICA occlusions, extracranial stenting followed by intracranial IA Abciximab and thrombectomy appears feasible, effective, and safe. Further evaluation of this treatment strategy is warranted.

Baseline collateral status and infarct topography in post-ischaemic perilesional hyperperfusion: An arterial spin labelling study

Focal hyperperfusion after acute ischaemic stroke could be of prognostic value depending upon its spatial localisation and temporal dynamics. Factors associated with late stage (12-24 h) perilesional hyperperfusion, identified using arterial spin labelling, are poorly defined. A prospective cohort of acute ischaemic stroke patients presenting within 4.5 h of symptom onset were assessed with multi-modal computed tomography acutely and magnetic resonance imaging at 24 ± 8 h. Multivariate logistic regression analysis and receiver operating characteristics curves were used. One hundred and nineteen hemispheric acute ischaemic stroke patients (mean age = 71 ± 12 years) with 24 h arterial spin labelling imaging were included. Forty-two (35.3%) patients showed perilesional hyperperfusion on arterial spin labelling at 24 h. Several factors were independently associated with perilesional hyperperfusion: good collaterals (71% versus 29%, P < 0.0001; OR = 5, 95% CI = [1.6, 15.7], P = 0.005), major reperfusion (81% versus 48%, P = < 0.0001; OR = 7.5, 95% CI = [1.6, 35.1], P = 0.01), penumbral salvage (76.2% versus 47%, P = 0.002; OR = 6.6, 95% CI = [1.8, 24.5], P = 0.004), infarction in striatocapsular (OR = 9.5, 95% CI = [2.6, 34], P = 0.001) and in cortical superior division middle cerebral artery (OR = 4.7, 95% CI = [1.4, 15.7], P = 0.012) territory. The area under the receiver operating characteristic curve was 0.91. Our results demonstrate good arterial collaterals, major reperfusion, penumbral salvage, and infarct topographies involving cortical superior middle cerebral artery and striatocapsular are associated with perilesional hyperperfusion.

Does stroke etiology play a role in predicting outcome of acute stroke patients who underwent endovascular treatment with stent retrievers?

AIMS

The goal of the study was to identify whether the stroke etiology play a role in the recanalization and outcome of patients who underwent mechanical thrombectomy with stent retrievers.

METHODS AND RESULTS

A retrospective analysis of a prospectively collected database included consecutive patients treated with stent retrievers. We included patients with cardioembolic stroke and large vessel atherosclerotic disease and compared risk factors for stroke, baseline NIHSS and Alberta Stroke Program Early CT scores (ASPECTS), stroke outcome, recanalization rate, onset-to-recanalization, onset-to-groin puncture time and the procedural time between two groups. Male sex was statistically more common in patients with large vessel atherosclerotic disease. Mean time from symptom onset- to the achievement of recanalization in patients with LVAD was 242±72.4 compared with cardioembolic stroke patients (301±70.7; p=0.014). Time for groin puncture to recanalization was longer in patients with cardioembolic stroke compared to LVAD group (97.5±44.3 vs 58.2±21.8; p=0.002). Time for microcatheter to successful recanalization or procedural termination was longer in patients with cardioembolic stroke compared to LVAD group (63.6±30.2 vs 34.2±19.4; p<0.001) with cardioembolic stroke had significantly worse long-term outcome (mRS 3-6) compared to those with LVAD (60.6% vs 26.3%; p=0.036).

CONCLUSION

Stroke etiology may play a role in the outcome of acute stroke patients who underwent endovascular stroke therapy. Cardioembolic strokes may be more resistant to endovascular acute stroke treatment.

Opercular Index Score: a CT angiography-based predictor of capillary robustness and neurological outcomes in the endovascular management of acute ischemic stroke

BACKGROUND

Many CT angiography (CTA) collateral scoring systems are either subjective or complex and time consuming.

OBJECTIVE

To evaluate the correlation between a CTA collateral scoring system-the Opercular Index Score (OIS)-with neurological outcomes at 90 days following endovascular treatment for acute ischemic stroke (AIS) secondary to large vessel occlusion.

METHODS

Fifty-five patients with AIS due to distal internal carotid artery, M1, or proximal M2 occlusions who underwent endovascular treatment were included. OIS was retrospectively calculated from CTA images, reconstructed from CT perfusion imaging, as the ratio of opacified M3 opercular branches in the Sylvian fissure on the unaffected side to those on the stroke side and dichotomized into favorable (OIS≤2) and poor (OIS>2). The ability of OIS to predict good neurological outcomes (modified Rankin Scale score ≤2 at 90 days) was assessed using sensitivity, specificity, and area under the curve (AUC) with receiver operating characteristic analysis.

RESULTS

Thirty-five patients had a favorable OIS and 20 patients had a poor OIS. Patients with favorable OIS had an 80.0% (n=28) rate of good neurological outcomes compared with 15.0% (n=3) of patients with a poor OIS (p<0.0001). On multivariate logistic regression analysis adjusting for baseline National Institutes of Health Stroke Scale score, OIS, and device used, favorable OIS was the only variable independently associated with good neurological outcome (OR=17.2, 95% CI 3.8 to 104.3) and demonstrated a sensitivity of 90.3% and specificity of 70.8% with an AUC of 0.822.

CONCLUSIONS

OIS is a simple and practical non-invasive scoring system that can be used to predict collateral robustness and good neurological outcome among patients with AIS undergoing endovascular treatment.

Association of Cortical Vein Filling with Clot Location and Clinical Outcomes in Acute Ischaemic Stroke Patients

Delay in cortical vein filling during the late-venous phase (delayed-LCVF) is characterized by opacification of cerebral veins despite contrast clearance from contralateral veins on dynamic computed tomography angiography (dCTA) in acute ischemic stroke (AIS) patients. The aim of the study was to investigate the associations of delayed-LCVF with clot location, reperfusion status at 24 hours, and 90-days functional outcome in AIS patients who received reperfusion therapy. A prospective cohort of AIS patients treated with intravenous thrombolysis was studied. Groupwise comparison, univariate, and multivariate regression analyses were used to study the association of delayed-LCVF with clot location and clinical outcomes. Of 93 patients (mean age = 72 ± 12 years) with hemispheric AIS included in the study, 46 (49%) demonstrated delayed-LCVF. Patients with delayed-LCVF demonstrated a significantly higher proportion of proximal occlusion (72% vs 13%, P =< 0.0001), and poor reperfusion at 24 hours (41% vs 11%, P = 0.001). The proportion of poor functional outcome at 90 days was not significantly different (22/56 (48%) vs 17/61 (36%), P = 0.297). The appearance of delayed-LCVF on baseline dCTA may be a surrogate for large vessel occlusion, and an early marker for poor 24-hour angiographic reperfusion.

Clinical Outcome Predicted by Collaterals Depends on Technical Success of Mechanical Thrombectomy in Middle Cerebral Artery Occlusion

BACKGROUND

This study aimed to analyze the effects of technical outcome of mechanical thrombectomy (MTE) on the associations between collateral status, assessed with pretreatment computed tomography angiography (CTA), and neurological and functional outcome, as well as associations between collaterals and metabolic risk factors (arterial hypertension, diabetes, hyperlipidemia, overweight).

METHODS

Prospectively collected data of 115 patients with CTA-proven isolated middle cerebral artery occlusion treated successfully with MTE (Thrombosis in Cerebral Infarction [TICI] scale 2b or 3) were assessed retrospectively. Initial CTAs were assessed for the regional leptomeningeal collateralization score (rLMC), neurological status was determined with the National Institutes of Health Stroke Scale (NIHSS) at admission and discharge, and mid-term functional outcome was assessed using the modified Rankin scale (mRS) 90 days after MTE.

RESULTS

NIHSS score at admission was significantly associated with rLMC (P = .004), whereas rLMC and NIHSS at discharge showed no significant associations (P = .12). Better rLMC was significantly associated with improved mid-term mRS (P = .018). This association was even more significant after complete MTE (TICI 3; P = .011). Arterial hypertension was significantly more often found in patients with poor rLMC (0-10) than in patients with good rLMC (11-20; P = .046), yet other risk factors showed no significant associations (P > .05).

CONCLUSIONS

In patients with successful MTE, good collaterals were associated with better neurological status at admission and favorable mid-term functional outcome. In patients with complete MTE, associations were even more significant compared with those with "almost complete" MTE, suggesting a synergistic effect between good collaterals and complete MTE and a predictive value of collaterals for estimation of the potential clinical benefit of MTE.

Systematic Review and Pooled Analyses of Recent Neurointerventional Randomized Controlled Trials: Setting a New Standard of Care for Acute Ischemic Stroke Treatment after 20 Years

BACKGROUND

Recent advances in the treatment of ischemic stroke have focused on revascularization and led to better clinical and functional outcomes. A systematic review and pooled analyses of 6 recent multicentered prospective randomized controlled trials (MPRCT) were performed to compare intravenous tissue plasminogen activator (IV tPA) and endovascular therapy (intervention) with IV tPA alone (control) for anterior circulation ischemic stroke (AIS) secondary to large vessel occlusion (LVO).

OBJECTIVES

Six MPRCTs (MR CLEAN, ESCAPE, EXTEND IA, SWIFT PRIME, REVASCAT and THERAPY) incorporating image-based LVO AIS were selected for assessing the following: (1) prespecified primary clinical outcomes of AIS patients in intervention and control arms: good outcomes were defined by a modified Rankin Scale score of 0-2 at 90 days; (2) secondary clinical outcomes were: (a) revascularization rates [favorable outcomes defined as modified Thrombolysis in Cerebral Infarction scale (mTICI) score of 2b/3]; (b) symptomatic intracranial hemorrhage (sICH) rates and mortality; (c) derivation of number needed to harm (NNH), number needed to treat (NNT), and relative percent difference (RPD) between intervention and control groups, and (d) random effects model to determine overall significance (forest and funnel plots).

RESULTS

A total of 1,386 patients were included. Good outcomes at 90 days were seen in 46% of patients in the intervention (p < 0.00001) and in 27% of patients in the control groups (p < 0.00002). An mTICI score of 2b/3 was achieved in 70.2% of patients in the intervention arm. The sICH and mortality in the intervention arm compared with the control arm were 4.7 and 14.3% versus 7.9 and 17.8%, respectively. The NNT and NNH in the intervention and control groups were 5.3 and 9.1, respectively. Patients in the intervention arm had a 50.1% (RPD) better chance of achieving a good 90-day outcome as compared to controls.

CONCLUSIONS

Endovascular therapy combined with IV tPA (in appropriately selected patients) for LVO-related AIS is superior to IV tPA alone. These results support establishing an endovascular therapy in addition to IV tPA as the standard of care for AIS secondary to LVO.

The Evolution of Mechanical Thrombectomy for Acute Stroke

OPINION STATEMENT

The natural history of an acute ischemic stroke from a large vessel occlusion (LVO) is poor and has long challenged stroke therapy. Recently, endovascular therapy has demonstrated superiority to medical management in appropriately selected patients. This advance has revolutionized acute care for LVO and mandates a reevaluation of the entire chain of stroke care delivery, including patient selection, intervention, and post-procedural care. Since endovascular therapy is a therapy specifically targeting LVO, its application should be restricted to those patients only. Clinical and radiologic parameters need to be considered in patient selection. Data supports that all patients over the age of 18 years presenting with a National Institutes of Health Stroke Scale (NIHSS) of 6 or greater within 6 hours of symptom onset should be considered for emergent endovascular therapy. Radiologically, those with a LVO of the internal carotid artery (ICA) or middle cerebral artery (MCA) M1 portion, intermediate or good collaterals and without large established infarct should be considered endovascular candidates. Selection beyond these parameters remains an open question and is being actively evaluated. In all cases, revascularization should be attempted with a new generation device (stentriever or direct aspiration), as these techniques are most likely to deliver adequate reperfusion. Post-revascularization, patients are closely monitored in an intensive care setting followed by discharge to rehabilitation, if required, or directly home. Patients should be evaluated in delayed fashion to assess recovery (typically at 3 months post-treatment). Ultimately, the poor natural history of ischemic stroke from LVO and the potential significant benefit from endovascular therapy over medical management alone necessitate a national response to ensure we identify and treat all eligible patients as rapidly and effectively as possible.

Time to redefine success? TICI 3 versus TICI 2b recanalization in middle cerebral artery occlusion treated with thrombectomy

BACKGROUND

The Thrombolysis in Cerebral Infarction (TICI) scale is the most widely applied scoring system to grade technical results of recanalizing therapies in acute ischemic stroke (AIS). TICI 2b and TICI 3 are conventionally subsumed as 'successful recanalization'. Previous studies reported conflicting results for the clinical relevance of achieving complete (TICI 3) versus 'almost' complete reperfusion (TICI 2b).

OBJECTIVE

To examine if neurologic outcome differs significantly between TICI 2b and TICI 3 in patients with AIS with middle cerebral artery (MCA) occlusion treated 'successfully' with mechanical thrombectomy (MTE).

METHODS

Retrospective analysis of prospectively collected data from 352 consecutive patients with isolated MCA occlusion subjected to MTE between January 2007 and July 2015.

RESULTS

262 of the 277 successfully treated patients had adequate follow-up and were included. Patients (n=119) in the TICI 3 group had a lower National Institutes of Health Stroke Scale score at discharge (NIHSS-DIS; median 5 vs 7, p=0.005), and showed higher rates of strong neurologic improvement (ΔNIHSS≥8 or NIHSS-DIS≤1, 68.4% vs 37.1%, p=0.002) and favorable NIHSS outcome (NIHSS-DIS≤5, 49.2% vs 31.9%, p=0.005). Hospital stays were shorter in the TICI 3 group (median 10 vs 12 days, p=0.014). After adjusting for relevant baseline and treatment parameters, TICI 3 was independently associated with strong neurologic improvement (OR=4.3, 95% CI 2.2 to 8.3, p<0.001) and favorable NIHSS outcome (OR=3.0, 95% CI 1.5 to 6.3, p=0.003).

CONCLUSIONS

Neurologic outcome is substantially better in TICI 3 than TICI 2b patients, and hospital stays are shorter. Endovascular strategies that consequently strive to achieve TICI 3 may be warranted and cost-effective, and should be examined by future research. TICI 3 rates should be included as a safety measure in studies evaluating MTE devices and techniques.

Neuroendovascular Interventions for Acute Ischemic Strokes in Patients Supported with Left Ventricular Assist Devices: A Single-Center Case Series and Review of the Literature

BACKGROUND

With the shortage of donor hearts, increasingly more patients with end-stage heart failure are implanted with left ventricular assist devices (LVADs). LVADs are associated with a significant risk of developing acute ischemic strokes (AISs). Very little is known on about the management of AIS in patients with LVAD, especially with regard to the safety and efficacy of neuroendovascular techniques.

METHODS

We identified 5 patients with heart failure and LVAD implants who developed AIS and underwent neuroendovascular interventions at Columbia University Medical Center. Their cases were reviewed for the safety, efficacy of the interventions, and potential complications.

RESULTS

There were no significant complications from the interventions. In all 5 cases, there was at least a 4-point improvement in the National Institutes of Health Stroke scale and none of the cases developed symptomatic hemorrhage. Two patients had substantial improvement and received cardiac transplantations.

CONCLUSIONS

Neuroendovascular intervention is safe and feasible in patients with LVAD and may potentially contribute to improving the outcome of a disease that has a poor natural history. Further study is recommended.

The Revascularization Scales Dilemma: Is It Right to Apply the Treatment in Cerebral Ischemia Scale in Posterior Circulation Stroke?

BACKGROUND AND PURPOSE

Although various revascularization scales are used in the angiographic evaluation of acute ischemic stroke, observer reliability tests of these scales have been rarely performed for posterior circulation stroke. We aimed to evaluate inter- and intraobserver variability of 2 scales, the modified Treatment in Cerebral Ischemia and the Arterial Occlusive Lesion, in posterior circulation stroke.

MATERIALS AND METHODS

Three independent readers interpreted pre- and postthrombolytic angiographies of 62 patients with posterior circulation stroke by using the modified Treatment in Cerebral Ischemia and Arterial Occlusive Lesion scales. The κ statistic was used to measure observer agreement for both scales, and κ > 0.6 was considered substantial agreement.

RESULTS

For the Arterial Occlusive Lesion scale, inter- and intraobserver agreement was >0.6. While intraobserver agreement of the modified Treatment in Cerebral Ischemia scale was >0.6 except for 1 reader, interobserver agreement was lower in dichotomized and original scales. In 49 cases with solely basilar artery occlusion, inter- and intraobserver agreement of both scales was similar to that in all 62 patients with posterior circulation stroke. In 2 consecutive readings, there was a significant decrease in the proportion of mTICI 2a reads (22.58% in the first versus 13.44% in the second session, P < .03) and a reciprocal increase in the sum of proportions for modified Treatment in Cerebral Ischemia 2b and modified Treatment in Cerebral Ischemia 3 reads (62.37% in the first versus 72.58% in the second session, P < .046).

CONCLUSIONS

In angiographic assessment of posterior circulation stroke, inter- and intraobserver agreement for the Arterial Occlusive Lesion scale was reliable, while the modified Treatment in Cerebral Ischemia failed to achieve substantial interobserver agreement. The clinical impact of this result needs to be validated in future studies.

Relationship Between Lesion Topology and Clinical Outcome in Anterior Circulation Large Vessel Occlusions

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) Alberta Stroke Program Early CT Score (ASPECTS), a surrogate of infarct volume, predicts outcome in anterior large vessel occlusion strokes. We aim to determine whether topological information captured by DWI ASPECTS contributes additional prognostic value.

METHODS

Adults with intracranial internal carotid artery, M1 or M2 middle carotid artery occlusions who underwent endovascular therapy were included. The primary outcome measure was poor clinical outcome (3-month modified Rankin Scale score, 3-6). Prognostic value of the 10 DWI ASPECTS regions in predicting poor outcome was determined by multivariable logistic regression, controlling for final infarct volume, age, and laterality.

RESULTS

Two hundred and thirteen patients (mean age, 66.1±14.5 years; median National Institutes of Health Stroke Scale, 15) were included. Inter-rater reliability was good for DWI ASPECTS (deep regions, κ=0.72; cortical regions, κ=0.63). All DWI ASPECTS regions with the exception of the putamen were significant predictors (P<0.05) of poor outcome in univariate analyses. Statistical collinearity among ASPECTS regions was not observed. Using penalized multivariable logistic regression, only M4 (odds ratio, 2.82; 95% confidence interval, 1.39-5.76) and M6 (odds ratio, 2.45; 95% confidence interval, 1.15-5.3) involvement were associated with poor outcome. M6 involvement independently predicted poor outcome in right hemispheric strokes (odds ratio, 5.8; 95% confidence interval, 1.9-20.3), whereas M4 (odds ratio, 4.3; 95% confidence interval, 1.3-15.0) involvement predicted poor outcome in left hemispheric strokes adjusting for infarct volume. Topologic information modestly improved the predictive ability of a prognostic score that incorporates age, infarct volume, and hemorrhagic transformation.

CONCLUSIONS

Involvement of the right parieto-occipital (M6) and left superior frontal (M4) regions affect clinical outcome in anterior large vessel occlusions over and above the effect of infarct volume and should be considered during prognostication.

Predictors of a Good Outcome after Endovascular Stroke Treatment with Stent Retrievers

Background and Purpose. Successful recanalization after endovascular stroke therapy (EVT) did not translate into a good clinical outcome in randomized trials. The goal of the study was to identify the predictors of a good outcome after mechanical thrombectomy with stent retrievers. Methods. A retrospective analysis of a prospectively collected database included consecutive patients treated with stent retrievers. We evaluated the influence of risk factors for stroke, baseline NIHSS score, Alberta Stroke Program Early CT (ASPECT) score, recanalization rate, onset-to-recanalization and onset-to-groin puncture time, and glucose levels at admission on good outcomes. The number of stent passes during procedure and symptomatic hemorrhage rate were also recorded. A modified Rankin Scale (mRS) score of 0–2 at 90 days was considered as a good outcome. Results. From January 2011 to 2014, 70 consecutive patients with an acute ischemic stroke underwent EVT with stent retrievers. The absence of a medical history of diabetes was associated with good outcomes. Apart from diabetes, the baseline demographic and clinical characteristics of patients were similar between subjects with poor outcome versus those with good outcomes. Median time from onset to recanalization was significantly shorter in patients with good outcomes 245 (IQR: 216–313 min) compared with poor outcome patients (315 (IQR: 240–360 min); P = 0.023). Symptomatic intracranial hemorrhage was observed in eight (21.6%) of 37 patients with poor outcomes and no symptomatic hemorrhage was seen in patients with good outcomes (P = 0.006). In multivariate stepwise logistic regression analysis, a favorable ASPECT score (ASPECT > 7) and successful recanalization after EVT were predictors of good outcomes. Every 10-year increase was associated with a 3.60-fold decrease in the probability of a good outcome at 3 months. The probability of a good outcome decreases by 1.43-fold for each 20 mg/dL increase in the blood glucose at admission. Conclusion. To achieve a good outcome after EVT with stent retrievers, quick and complete recanalization and better strategies for patient selection are warranted. We need randomized trials to identify the significance of tight blood glucose control in clinical outcome during or after EVT.

Intra-arterial therapy for acute ischemic stroke: a golden age

OPINION STATEMENT

With the recent publication of multiple trials demonstrating the superiority of the endovascular treatment of patients presenting with stroke from large vessel occlusion (LVO) over medical management, the emergent care of these patients is entering a new era. This realization justifies an aggressive treatment approach with these stroke patients, given the poor natural history of the disease. In general, treatment should occur as quickly as is reasonably possible. Patients with NIHSS >8 should be considered, and if <6 h from onset imaging selection achieved with CT and CTA. Those with ASPECTS >5, LVO and intermediate or good collaterals should be treated emergently. For patients with clinical deficits presenting in later timeframes MRI should be used to define core infarct size and therefore treatment eligibility. MRI might also be considered for the workup of stroke patients in centers that can offer it rapidly. Recanalization should be attempted with a stentriever or using a direct aspiration technique, with the patient under conscious sedation rather than general anesthesia, if that is a safe option. Angiographically, the goal is reperfusion of mTICI 2b/3. Post-procedure, the patient should be admitted to an intensive care setting and assessed for inpatient rehabilitation placement as soon as stable. Continuous institutional process improvement ensures that optimization of treatment times and logistics is an ongoing endeavor. Finally, patient outcomes should be assessed at three months, most commonly using the modified Rankin score.