Large deep white matter lesions may predict futile recanalization in endovascular therapy for acute ischemic stroke

No-reflow after recanalization in ischemic stroke: From pathomechanisms to therapeutic strategies

Endovascular reperfusion therapy is the primary strategy for acute ischemic stroke. No-reflow is a common phenomenon, which is defined as the failure of microcirculatory reperfusion despite clot removal by thrombolysis or mechanical embolization. It has been reported that up to 25% of ischemic strokes suffer from no-reflow, which strongly contributes to an increased risk of poor clinical outcomes. No-reflow is associated with functional and structural alterations of cerebrovascular microcirculation, and the injury to the microcirculation seriously hinders the neural functional recovery following macrovascular reperfusion. Accumulated evidence indicates that pathology of no-reflow is linked to adhesion, aggregation, and rolling of blood components along the endothelium, capillary stagnation with neutrophils, astrocytes end-feet, and endothelial cell edema, pericyte contraction, and vasoconstriction. Prevention or treatment strategies aim to alleviate or reverse these pathological changes, including targeted therapies such as cilostazol, adhesion molecule blocking antibodies, peroxisome proliferator-activated receptors (PPARs) activator, adenosine, pericyte regulators, as well as adjunctive therapies, such as extracorporeal counterpulsation, ischemic preconditioning, and alternative or complementary therapies. Herein, we provide an overview of pathomechanisms, predictive factors, diagnosis, and intervention strategies for no-reflow, and attempt to convey a new perspective on the clinical management of no-reflow post-ischemic stroke.

Lymphocyte to Monocyte Ratio is Independently Associated with Futile Recanalization in Acute Ischemic Stroke After Endovascular Therapy

Background and Purpose

Acute ischemic stroke (AIS) caused by large artery occlusion (LAO) poses considerable risks in terms of mortality and disability. Endovascular treatment (EVT) has emerged as a primary intervention for this condition. However, the occurrence of futile recanalization (FR) following EVT remains common, necessitating the identification of predictive markers for treatment outcomes. Although the lymphocyte to monocyte ratio (LMR) has been linked to various diseases, its association with FR after EVT in AIS patients has not been investigated.

Methods

An analysis was conducted on patients with AIS who underwent EVT within 24 hours of symptom onset. The success of reperfusion was evaluated using the modified Thrombolysis in Cerebral Infarction (mTICI) scale, with patients achieving an mTICI score of ≥2b being included in the study. Various clinical, radiological, and laboratory variables, including lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), were collected. Logistic regression analysis was used to determine factors associated with FR, and receiver operating characteristic (ROC) analysis was performed to assess the predictive value of LMR.

Results

Among the cohort of 101 patients, it was observed that 52.4% experienced FR. Upon admission, lower levels of lymphocyte-to-monocyte ratio (LMR) were found to be associated with older age, higher baseline NIHSS scores, lower ASPECTS, and poorer mRS scores at 90 days. Both univariate and multivariate logistic regression analyses indicated that low LMR independently predicted FR, with an adjusted odds ratio of 0.64 (95% CI = 0.412-0.984, p = 0.042). ROC analysis further demonstrated that LMR had an area under the curve (AUC) of 0.789 for predicting FR.

Conclusion

This study establishes the potential value of the lymphocyte-to-monocyte ratio (LMR) as a prognostic marker for predicting FR in patients with AIS undergoing EVT. Decreased LMR levels are associated with unfavorable clinical outcomes.

Comprehensive Meta-Analysis of Futile Recanalization in Acute Ischemic Stroke Patients Undergoing Endovascular Thrombectomy: Prevalence, Factors, and Clinical Outcomes

BACKGROUND

Futile recanalization (FR) continues to raise concern despite the success of endovascular thrombectomy (EVT) in acute ischemic stroke (AIS). Understanding the prevalence of FR and identifying associated factors are crucial for refining patient prognoses and optimizing management strategies.

OBJECTIVES

This study aims to comprehensively assess the pooled prevalence of FR, explore the diverse factors connected with FR, and establish the association of FR with long-term clinical outcomes among AIS patients undergoing EVT.

MATERIALS AND METHODS

Incorporating studies focusing on FR following EVT in AIS patients, we conducted a random-effect meta-analysis to assess the pooled prevalence and its association with various clinical and imaging risk factors linked to FR. Summary estimates were compiled and study heterogeneity was explored.

RESULTS

Our comprehensive meta-analysis, involving 11,700 AIS patients undergoing EVT, revealed a significant pooled prevalence of FR at 51%, with a range of 48% to 54% (Effect Size [ES]: 51%; 95% Confidence Interval [CI]: 48-54%; z = 47.66; p < 0.001). Numerous clinical factors demonstrated robust correlations with FR, including atrial fibrillation (Odds Ratio [OR]: 1.39, 95% CI 1.22 1.59; p < 0.001), hypertension (OR 1.65, 95% CI 1.41 1.92; p < 0.001), diabetes mellitus (OR 1.71, 95% CI 1.47 1.99; p < 0.001), previous stroke or transient ischemic attack (OR 1.298, 95% CI 1.06 1.59; p = 0.012), prior anticoagulant usage (OR 1.33, 95% CI 1.08 1.63; p = 0.007), cardioembolic strokes (OR 1.34, 95% CI 1.10 1.63; p = 0.003), and general anesthesia (OR 1.53, 95% CI 1.35 1.74; p < 0.001). Conversely, FR exhibited reduced likelihoods of smoking (OR 0.66, 95% CI 0.57 0.77; p < 0.001), good collaterals (OR 0.33, 95% CI 0.23 0.49; p < 0.001), male sex (OR 0.87, 95% CI 0.77 0.97; p = 0.016), and intravenous thrombolysis (IVT) (OR 0.75, 95% CI 0.66 0.86; p < 0.001). FR was strongly associated with increasing age (standardized mean difference [SMD] 0.49, 95% CI 0.42 0.56; p < 0.0001), baseline systolic blood pressure (SMD 0.20, 95% CI 0.13 0.27; p < 0.001), baseline National Institute of Health Stroke Severity Score (SMD 0.75, 95% CI: 0.65 0.86; p < 0.001), onset-to-treatment time (SMD 0.217, 95% CI 0.13 0.30; p < 0.001), onset-to-recanalization time (SMD 0.38, 95% CI 0.19; 0.57; p < 0.001), and baseline blood glucose (SMD 0.31, 95% CI 0.22 0.41; p < 0.001), while displaying a negative association with reduced baseline Alberta Stroke Program Early CT Score (ASPECTS) (SMD -0.37, 95% CI -0.46 -0.27; p < 0.001). Regarding clinical outcomes, FR was significantly associated with increased odds of symptomatic intracranial hemorrhages (OR 7.37, 95% CI 4.89 11.12; p < 0.001), hemorrhagic transformations (OR 2.98, 95% CI 2.37 3.75; p < 0.001), and 90-day mortality (OR 19.24, 95% CI 1.57 235.18; p = 0.021).

CONCLUSIONS

The substantial prevalence of FR, standing at approximately 51%, warrants clinical consideration. These findings underscore the complexity of FR in AIS patients and highlight the importance of tailoring management strategies based on individual risk factors and clinical profiles.

Predictors of Futile Recanalization in Patients with Intracranial Atherosclerosis-Related Stroke Undergoing Endovascular Treatment

OBJECTIVE

The predictors of futile recanalization in patients with intracranial atherosclerosis (ICAS)-related stroke are not understood. This study aimed to identify the predictors of futile recanalization after endovascular treatment (EVT) in patients who experience an acute stroke caused by ICAS-related occlusion.

METHODS

We retrospectively reviewed the data of patients with ICAS-related stroke who underwent EVT from January 2018 to July 2021. Futile recanalization was defined as functional dependence (modified Rankin scale 3-6) despite successful reperfusion (modified Thrombolysis in Cerebral Infarction score of 2 b/3). Multivariate logistic regression analysis was used to determine the risk factors associated with futile recanalization. The receiver operating characteristic curve was used to examine the predictive value of the risk prediction model for futile recanalization.

RESULTS

Of the 87 patients enrolled, futile recanalization was observed in 32 (36.8%). Multivariate logistic analysis showed that older age (OR, 1.05; 95% CI, 1.01-1.10; P = 0.026), a higher National Institutes of Health Stroke Scale (NIHSS) score on admission (OR, 1.25; 95% CI, 1.08-1.45; P = 0.003), and poor collaterals (OR, 5.49; 95% CI, 1.70-17.79; P = 0.004) were independently associated with futile recanalization after EVT in patients with ICAS-related stroke. The receiver operating characteristic curve showed that the model in combination with age, admission NIHSS score, and collateral status could accurately predict futile recanalization in these patients (areas under the curve, 0.85; 95% CI, 0.76-0.92; P < 0.001).

CONCLUSIONS

Older age, higher NIHSS score on admission, and poor collaterals are predictors of futile recanalization in patients with ICAS-related stroke.

Nomogram-Based Prediction of the Futile Recanalization Risk Among Acute Ischemic Stroke Patients Before and After Endovascular Therapy: A Retrospective Study

Background and Purpose

Futile recanalization (FRC) is common among large artery occlusion (LAO) patients after endovascular therapy (EVT). We developed nomogram models to identify LAO patients at a high risk of FRC pre- and post-EVT to help neurologists select the optimal candidates for EVT.

Methods

From April 2020 to July 2022, EVT and mTICI score ≥2b LAO patients were recruited. Nomogram models was developed by two-step approach for predicting the outcomes of LAO patients. First, the least absolute shrinkage and selection operator (LASSO) regression analysis was to optimize variable selection. Then, a multivariable analysis was to construct an estimation model with significant indicators from the LASSO. The accuracy of the model was verified using receiver operating characteristic (ROC), calibration curve, and decision curve analyses (DCA), along with validation cohort (VC).

Results

Using LASSO, age, sex, hypertension history, baseline NIHSS, ASPECTS and baseline SBP upon admission were identified from the pre-EVT variables. Model 1 (pre-EVT) showed good predictive performance, with an area under the ROC curve (AUC) of 0.815 in the training cohort (TrC) and 0.904 in VC. Under the DCA, the generated nomogram was clinically applicable where risk cut-off was between 15%-85% in the TrC and 5%-100% in the VC. Moreover, age, ASPECTS upon admission, onset duration, puncture-to-recanalization (PTR) duration, and lymphocyte-to-monocyte ratio (LMR) were screened by LASSO. Model 2 (post-EVT) also demonstrated good predictive performance with AUCs of 0.888 and 0.814 for TrC and VC, respectively. Under the DCA, the generated nomogram was clinically applicable if the risk cut-off was between 13-100% in the TrC and 22-85% of VC.

Conclusion

In this study, two nomogram models were generated that showed good discriminative performance, improved calibration, and clinical benefits. These nomograms can potentially accurately predict the risk of FRC in LAO patients pre- and post-EVT and help to select appropriate candidates for EVT.

Predictors of futile recanalization in patients with acute ischemic stroke undergoing mechanical thrombectomy in late time windows

Background and purpose

Futile recanalization (FR), defined as functional dependence despite successful reperfusion, is common in patients who experience an acute stroke after thrombectomy. We aimed to determine the predictors of FR in patients who underwent thrombectomy in late time windows (6 h or more after symptom onset).

Methods

This retrospective review included patients who underwent thrombectomy for acute anterior circulation large vessel occlusion from October 2019 to June 2021. Successful reperfusion was defined as a modified Thrombolysis in Cerebral Infarction (mTICI) score of 2b/3. Functional dependence at 90 days was defined as a modified Rankin scale score of 3–6. Multivariate analysis and a receiver operating characteristic (ROC) curve were used to identify the predictors of FR in patients treated in delayed time windows.

Results

Of the 99 patients included, FR was observed in 51 (51.5%). In the multivariate analysis, older age (OR, 1.12; 95% CI, 1.04–1.22; P = 0.005), female sex (OR, 3.79; 95% CI, 1.08–13.40; P = 0.038), a higher National Institutes of Health Stroke Score (NIHSS) score upon admission (OR, 1.11; 95% CI, 1.02–1.22; P = 0.023), and an increased number of passes per procedure (OR, 2.07; 95% CI, 1.11–3.86; P = 0.023) were independently associated with FR after thrombectomy. The ROC curve indicated that the model that combined age, female sex, baseline NIHSS score, and the number of passes per procedure (area under the curve, 0.84; 95% CI, 0.75–0.90, P < 0.001) was able to predict FR accurately.

Conclusions

Older age, female sex, higher NIHSS score upon admission, and an increased number of passes per procedure were independent predictors of FR in patients who experienced acute ischemic strokes after thrombectomy in late time windows.

Predictors of futile recanalization after endovascular treatment in acute ischemic stroke: a meta-analysis

BACKGROUND

Despite successful recanalization after endovascular treatment, many patients with acute ischemic stroke due to large vessel occlusion still show functional dependence, namely futile recanalization.

METHODS

PubMed and Embase were searched up to April 30, 2021. Studies that reported risk factors for futile recanalization following endovascular treatment of acute ischemic stroke were included. The mean difference (MD) or odds ratio (OR) and 95% confidence interval (95% CI) of each study were pooled for a meta-analysis.

RESULTS

Twelve studies enrolling 2138 patients were included. The pooled analysis showed that age (MD 5.81, 95% CI 4.16 to 7.46), female sex (OR 1.40, 95% CI 1.16 to 1.68), National Institutes of Health Stroke Scale (NIHSS) score (MD 4.22, 95% CI 3.38 to 5.07), Alberta Stroke Program Early CT Score (ASPECTS) (MD -0.71, 95% CI -1.23 to -0.19), hypertension (OR 1.73, 95% CI 1.43 to 2.09), diabetes (OR 1.78, 95% CI 1.41 to 2.24), atrial fibrillation (OR 1.24, 95% CI 1.01 to 1.51), admission systolic blood pressure (MD 4.98, 95% CI 1.87 to 8.09), serum glucose (MD 0.59, 95% CI 0.37 to 0.81), internal carotid artery occlusion (OR 1.85, 95% CI 1.17 to 2.95), pre-treatment intravenous thrombolysis (OR 0.67, 95% CI 0.55 to 0.83), onset-to-puncture time (MD 16.92, 95% CI 6.52 to 27.31), puncture-to-recanalization time (MD 12.37, 95% CI 7.96 to 16.79), and post-treatment symptomatic intracerebral hemorrhage (OR 6.09, 95% CI 3.18 to 11.68) were significantly associated with futile recanalization.

CONCLUSION

This study identified female sex, comorbidities, admission systolic blood pressure, serum glucose, occlusion site, non-bridging therapy, and post-procedural complication as predictors of futile recanalization, and also confirmed previously reported factors. Further large-scale prospective studies are needed.

Multiple-Factor Analyses of Futile Recanalization in Acute Ischemic Stroke Patients Treated With Mechanical Thrombectomy

Background and Purpose: Acute ischemic stroke (AIS) is a serious threat to the life and health of middle-aged and elderly people. Mechanical thrombectomy offers the advantages of rapid recanalization, but the response of patients to this treatment varies greatly. This study investigated the risk factors for futile recanalization in AIS patients after thrombectomy through multivariate analyses. Methods: A retrospective study was conducted in AIS patients with anterior circulation occlusion from a derivation cohort and a validation cohort who underwent thrombectomy and reperfusion defined as a modified Thrombolysis in Cerebral Infarction (mTICI) score of 2b/3. Using the modified Rankin Scale (mRS) at 90 days after the operation, the patients were divided into two groups, the meaningful recanalization group (mRS ≤ 2), and the futile recanalization group (mRS > 2). Multivariate logistic regression analyses were performed, and the receiver operating characteristic (ROC) curve was used to construct a risk prediction model for futile recanalization. The performance of prediction model was evaluated on the validation cohort. Results: A total of 140 patients in the derivation cohort were enrolled, 46 patients in the meaningful recanalization group and 94 patients in the futile recanalization group. The two groups were significantly different in age, preoperative National Institute of Health Stroke Scale (NIHSS) score, and collateral circulation ASITN/SIR grade (P < 0.05). In multivariate regression analyses, patients' age ≥ 71, NIHSS ≥ 12, and ASITN/SIR ≤ 3 were risk factors for futile recanalization. Hence, an ANA (Age-NIHSS-ASITN/SIR) score scale consisting of age, NIHSS score, and ASITN/SIR grade factors can effectively predict the risk for futile recanalization (area under curve 0.75, 95% CI 0.67-0.83, specificity 67.4%, and sensitivity 73.4%). The proportion of patients with futile recanalization in ANA groups 0, 1, 2, and 3 were 21.05, 56.76, 79.03, and 90.91%, respectively. Furthermore, ANA score scale had also a good performance for predicting futile recanalization on the validation cohort. Conclusions: Old age, high baseline NIHSS, and poor collateral circulation are risk factors for futile recanalization in AIS patients treated with thrombectomy. An ANA score that considers age, NIHSS, and collateral ASITN/SIR can effectively predict the risk for futile recanalization. Further studies with a larger sample size are needed to validate the prognostic value of this combined score for futile recanalization.

White Matter Lesions and Outcomes After Endovascular Treatment for Acute Ischemic Stroke: MR CLEAN Registry Results

Supplemental Digital Content is available in the text.

Background:

Cerebral white matter lesions (WMLs) have been associated with a greater risk of poor functional outcome after ischemic stroke. We assessed the relations between WML burden and radiological and clinical outcomes in patients treated with endovascular treatment in routine practice.

Methods:

We analyzed data from the MR CLEAN Registry (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischaemic Stroke in the Netherlands)—a prospective, multicenter, observational cohort study of patients treated with endovascular treatment in the Netherlands. WMLs were graded on baseline noncontrast computed tomography using a visual grading scale. The primary outcome was the score on the modified Rankin Scale at 90 days. Secondary outcomes included early neurological recovery, successful reperfusion (extended Thrombolysis in Cerebral Infarction ≥2b), futile recanalization (modified Rankin Scale score ≥3 despite successful reperfusion), and occurrence of symptomatic intracranial hemorrhage. We used multivariable logistic regression models to assess associations between WML severity and outcomes, taking the absence of WML on noncontrast computed tomography as the reference category.

Results:

Of 3180 patients included in the MR CLEAN Registry between March 2014 and November 2017, WMLs were graded for 3046 patients and categorized as none (n=1855; 61%), mild (n=608; 20%), or moderate to severe (n=588; 19%). Favorable outcome (modified Rankin Scale score, 0–2) was achieved in 838 patients (49%) without WML, 192 patients (34%) with mild WML, and 130 patients (24%) with moderate-to-severe WML. Increasing WML grades were associated with a shift toward poorer functional outcome in a dose-dependent manner (adjusted common odds ratio, 1.34 [95% CI, 1.13–1.60] for mild WML and 1.67 [95% CI, 1.39–2.01] for moderate-to-severe WML; P_trend, <0.001). Increasing WML grades were associated with futile recanalization (P_trend, <0.001) and were inversely associated with early neurological recovery (P_trend, 0.041) but not with the probability of successful reperfusion or symptomatic intracranial hemorrhage.

Conclusions:

An increasing burden of WML at baseline is associated with poorer clinical outcomes after endovascular treatment for acute ischemic stroke but not with the probability of successful reperfusion or symptomatic intracranial hemorrhage.

Association between mitral regurgitation and clinical outcome after endovascular thrombectomy in stroke patients

OBJECTIVE

Some hyperacute stroke patients have unfavorable outcomes after endovascular thrombectomy (EVT) despite successful recanalization. We hypothesized that a cardiac parameter, moderate-to-severe mitral regurgitation (MR), might decrease the rate of favorable clinical outcome after EVT in patients with atrial fibrillation (AF).

METHOD

From our prospective EVT registry, AF patients who underwent transthoracic echocardiography (TTE) were retrospectively analyzed. Based on the presence of moderate-to-severe MR, patients were assigned to either significant MR or nonsignificant MR group. The severity of MR was determined by the ratio of the color Doppler jet area to the left atrial area in mid-systole. Moderate-to-severe MR was estimated to be at a ratio of >20%. Favorable outcome was defined as having a modified Rankin Scale score of 0-1 at 3 months.

RESULT

127 patients with AF who underwent TTE were included in the study. TTE results found that 25 (20%) patients had significant MR. Patients with significant MR were older (p = 0.051) and had enlarged left (p = 0.015) and right (p = 0.002) atria. Tricuspid and aortic regurgitation (p = 0.007 and 0.043, respectively) were more severe in significant MR group. At 3 months, favorable outcomes were 11% in the significant MR group and 26% in the non-significant MR group (p = 0.031). Multivariate regression analysis reported that moderate-to-severe MR was a negative predictor of favorable outcome (odds ratio = 0.14; 95% confidence interval = 0.02, 0.84; p = 0.031).

CONCLUSIONS

Significant MR might prevent the clinical recovery of AF patients.

Effects of hypertension in patients receiving mechanical thrombectomy: A meta-analysis

BACKGROUND

Available evidence shows conflicting results with regard to a potential detrimental effect of hypertension on clinical outcomes in patients who undergo mechanical thrombectomy (MT). We performed a meta-analysis to evaluate the impact of hypertension on the prognosis of patients with acute ischaemic stroke (AIS) treated by MT.

METHODS

We systematically reviewed previous studies in the PubMed, EMBASE, and Cochrane library databases that reported MT outcomes in AIS patients and their relationships with hypertension or blood pressure. We used a poor outcome (modified Rankin score >2 at 3 months) as the primary end point. Mortality and symptomatic intracranial hemorrhage were the secondary end points. We incorporated a random effect for trials in all models.

RESULTS

Data from 6650 patients in 31 articles that evaluated the effect of hypertension or blood pressure on outcomes after MT were included. Compared with patients without hypertension, patients with hypertension had significantly higher odds of a poor outcome (odds ratio 0.70; 95% confidence interval 0.57-0.85; I = 43%) and higher mortality (odds ratio 1.70; 95% confidence interval 1.26-2.29; I = 33%). Symptomatic intracranial hemorrhage did not differ by patient hypertension status.

CONCLUSIONS

The present study confirms that hypertension and high blood pressure are associated with a poor outcome at 3 months after MT in AIS patients. However, the causal relationship between hypertension and a poor outcome remains undetermined, and further investigations are required to ascertain whether AIS patients receiving MT could benefit from intensive blood pressure control.

Futile Recanalization after Endovascular Therapy in Acute Ischemic Stroke

Early recanalization after endovascular treatment could improve the prognosis of acute ischemia stroke. Futile recanalization often occurred which was one of the main causes of failure. By now the mechanisms of futile recanalization were not clear. They are probably concerned with bad collateral circulation, subacute reocclusion, large hypoperfusion volumes, microvascular compromise, and impaired cerebral autoregulation. Previous research found that some of the image markers could be used as the accurate predictors for poor prognosis after successful treatment in order to identify the patients who were not suitable for recanalization and reduce some of the unnecessary cost. Predictors for futile recanalization mentioned in our article can be used for supplement to make decision for endovascular treatment.

Cerebral venous collaterals: A new fort for fighting ischemic stroke?

Stroke therapy has entered a new era highlighted by the use of endovascular therapy in addition to intravenous thrombolysis. However, the efficacy of current therapeutic regimens might be reduced by their associated adverse events. For example, over-reperfusion and futile recanalization may lead to large infarct, brain swelling, hemorrhagic complication and neurological deterioration. The traditional pathophysiological understanding on ischemic stroke can hardly address these occurrences. Accumulating evidence suggests that a functional cerebral venous drainage, the major blood reservoir and drainage system in brain, may be as critical as arterial infusion for stroke evolution and clinical sequelae. Further exploration of the multi-faceted function of cerebral venous system may add new implications for stroke outcome prediction and future therapeutic decision-making. In this review, we emphasize the anatomical and functional characteristics of the cerebral venous system and illustrate its necessity in facilitating the arterial infusion and maintaining the cerebral perfusion in the pathological stroke content. We then summarize the recent critical clinical studies that underscore the associations between cerebral venous collateral and outcome of ischemic stroke with advanced imaging techniques. A novel three-level venous system classification is proposed to demonstrate the distinct characteristics of venous collaterals in the setting of ischemic stroke. Finally, we discuss the current directions for assessment of cerebral venous collaterals and provide future challenges and opportunities for therapeutic strategies in the light of these new concepts.

Cerebral regions preserved by successful endovascular recanalization of acute M1 segment occlusions: a voxel based analysis

OBJECTIVE

To identify cerebral regions preserved by successful recanalization of the middle cerebral artery M1 segment and their association with early clinical outcome.

METHODS

47 patients who underwent endovascular treatment for acute unilateral M1 segment occlusion were included. Successful recanalization was defined by a modified thrombolysis in cerebral infarction score of 2b/3. Final infarct volumes were segmented on follow-up MRI/CT, 2-7 days post-symptom onset. The differences in topography of infarct lesions associated with successful vs unsuccessful recanalization were assessed using voxel-based analysis. Favourable outcome was defined by a modified Rankin Scale score ≤2 at discharge, and disability/death by score >2.

RESULTS

Successful recanalization of M1 segment occlusion was achieved in 26/47 (55%) patients, which was associated with higher rate of favourable outcome (54% vs 9%, p = 0.002) and smaller final infarct volumes (34.3 ± 43.7 vs 98.1 ± 47.7 ml, p < 0.001). In voxel-based analysis, patients with successful recanalization had a lower rate of infarction in precentral gyrus and posterior insular ribbon compared with those without recanalization. Favourable outcome was achieved in 16 (34%) patients, who were younger (62.2 ± 13.9 vs 70.9 ± 13.9, p = 0.048), had higher rate of successful recanalization (88% vs 39%, p = 0.002) and had smaller infarct volumes (25.2 ± 23.6 vs 82.2 ± 57.1 ml, p < 0.001) compared with those with disability/death. In voxel-based analysis, infarction of the insula, precentral gyrus, middle centrum semiovale and corona radiata were associated with disability/death.

CONCLUSION

Successful endovascular recanalization of acute M1 segment occlusion tends to preserve posterior insular ribbon and precentral gyrus from infarction; and infarction of these regions was associated with higher rates of disability/death. Advances in knowledge: The knowledge of the topographic location of potentially salvageable cerebral tissue can provide additional information for treatment triage and selection of patients with acute stroke for endovascular treatment based on the "areas at risk" rather than the "volume at risk". Also, such knowledge can help with preferential recanalization, where the neurointerventionalist may choose to preferentially recanalize certain branches supplying salvageable and eloquent cerebral regions in favour of timely reperfusion treatment.

DWI Lesion Patterns Predict Outcome in Stroke Patients with Thrombolysis

BACKGROUND

Lesion patterns may predict prognosis after acute ischemic stroke within the middle cerebral artery (MCA) territory; yet it remains unclear whether such imaging prognostic factors are related to patient outcome after intravenous thrombolysis.

AIMS

The aim of this study is to investigate the clinical outcome after intravenous thrombolysis in acute MCA ischemic strokes with respect to diffusion-weighted imaging (DWI) lesion patterns.

METHODS

Consecutive acute ischemic stroke cases of the MCA territory treated over a 7-year period were retrospectively analyzed. All acute MCA stroke patients underwent a MRI scan before intravenous thrombolytic therapy was included. DWI lesions were divided into 6 patterns (territorial, other cortical, small superficial, internal border zone, small deep, and other deep infarcts). Lesion volumes were measured by dedicated imaging processing software. Favorable outcome was defined as modified Rankin scale (mRS) of 0-2 at 90 days.

RESULTS

Among the 172 patients included in our study, 75 (43.6%) were observed to have territorial infarct patterns or other deep infarct patterns. These patients also had higher baseline NIHSS score (p < 0.001), a higher proportion of large cerebral artery occlusions (p < 0.001) and larger infarct volume (p < 0.001). Favorable outcome (mRS 0-2) was achieved in 89 patients (51.7%). After multivariable analysis, groups with specific lesion patterns, including territorial infarct and other deep infarct pattern, were independently associated with favorable outcome (OR 0.40; 95% CI 0.16-0.99; p = 0.047).

CONCLUSIONS

Specific lesion patterns predict differential outcome after intravenous thrombolysis therapy in acute MCA stroke patients.