Reliability assessment of distal occlusion eTICI scoring.

BACKGROUND: The eThrombolysis in Cerebral Infarction (eTICI) score has been validated in proximal large artery occlusion (pLAOs). Despite the growing number of distal medium vessel occlusions (DMVOs) mechanical thrombectomies (MT) and the widespread utilization of the eTICI scoring system, its reliability and standardization for more distal occlusions have not been validated. We aim to evaluate the interrater reliability of eTICI scores in primary DMVOs. METHODS: This was a retrospective analysis of a prospectively maintained database for consecutive patients with pLAO and DMVO MT at a single comprehensive stroke center from 2015 to 2022. Two fellowship-trained neurointerventionalists blindly/independently assessed digital subtraction angiograms for final eTICI, followed by consensus reads for discrepancies. RESULTS: 59 DMVO of 2248 thrombectomies [M3:29(50%)/M4:1(2%)/A1:3(5%)/A2:12(22%)/A3: 5(9%)/P1:7(12%)/P2:1(2%)] and 124 pLAOs of 308 thrombectomies [i-ICA:13(11%)/MCA-M1: 111(90%)] were included. The distribution of final eTICI scores was comparable between pLAO vs DMVOs (p = 0.82). The pLAO final eTICI score assessment between two readers demonstrated moderate reliability with a kappa0.77 (95%CI: 0.67-0.88), while the DMVO eTICI score assessment exhibited almost-perfect agreement with kappa 0.94 (95%CI: 0.90-0.99). The agreement between the consensus read and the original report in DMVOs was 0.86 (95% CI: 0.71-1.00) while for pLAO it was 0.83(95% CI: 0.76-0.90). The performance of eTICI was comparable amongst different DMVO territories as well as for distal vs. very distal occlusions. CONCLUSION: eTICI score exhibited comparable performance for DMVO as compared to pLAO strokes. Further studies investigating DMVO eTICI grading and clinical outcomes are warranted.

Basilar artery bifurcation anatomy as a determinant of recanalization and stroke outcome: Basilar artery bifurcation anatomy and stroke outcome.

OBJECTIVES: Thrombectomy improves outcomes in patients with basilar artery (BA) occlusion. We hypothesized that the anatomic configuration of the BA bifurcation, classified as T- or Y-shaped, may impact the outcome as a T-shaped BA would involve more deep penetrating arteries of the midbrain and thalamus. MATERIALS AND METHODS: In this 2-center retrospective cohort study, we included patients with stroke due to distal BA occlusion and performed blinded classification of their BA distal bifurcation as either T- or Y-shaped. The primary outcomes were favorable outcome at 90-days (modified Rankin Scale 0 - 2) and successful recanalization (TICI scores 2B or 3). RESULTS: 70 patients (mean age 66 years, 36% women) were included. 38 had T- and 32 had Y-shaped bifurcations. Baseline characteristics were similar for both groups, including demographics, onset to arterial puncture time, baseline NIHSS, THRIVE score, posterior circulation collateral score, and presence of tandem occlusion. Comparing the T- to the Y- shape, there was no difference in the likelihood of successful recanalization (RR: 1.02, CI: [0.86-1.21], p=1.00) nor 90-day favorable mRS (0-2) score (RR: 0.58, CI: [0.25-1.32]; p=0.18). Similarly, mortality at 30 and 90-days were not significantly affected by the type of bifurcation. CONCLUSIONS: The configuration of the basilar artery does not significantly impact on recanalization success or stroke outcome in our study. Further studies are needed to confirm our observations.

Complete Recanalization in Mechanical Thrombectomy Is Associated with Favorable Functional Outcome for M2 Occlusions.

Objective: There are insufficient coherent reports on mechanical thrombectomy (MT) for occlusion of the second segment of the middle cerebral artery (M2 occlusion) in a real-world clinical setting. We evaluated the efficacy and safety of MT for M2 occlusions and compared the primary thrombectomy strategies (stent retriever, aspiration catheter, and combined technique) to analyze factors predicting good functional outcomes. Methods: We evaluated background factors, preprocedural factors, procedural factors, and procedural time for patients who underwent MT for M2 occlusions from our retrospective cohort. According to the modified Rankin Scale (mRS) score three months after MT, patients were divided into good (mRS ≤2) and poor (mRS ≥3) prognosis groups. Results: A total of 29 patients (median age, 78 years; 11 [37.9%] females) were included in the study. In this cohort, rates of successful reperfusion, thrombolysis in cerebral infarction (TICI) 3, postprocedural hemorrhage (PPH), and symptomatic PPH were 82.8, 34.5, 31.0, and 0%, respectively. Good prognoses were achieved in 13 (45%) cases. A prognostic factor of MT for M2 occlusions is TICI 3 from multivariate analysis (OR, 11.7; 95% CI, 1.003-136; p = 0.0497). There was no statistically significant difference in the functional outcome three months after MT based on the choice of the primary thrombectomy strategy. Conclusion: MT for M2 occlusions is a reliable and relatively safe procedure. The presence of TICI 3 was a prognostic factor in this cohort. Future studies are warranted to investigate the optimal thrombectomy strategy for medium vessel occlusion.

Reversible CT Scan Hypodensity in Acute Ischemic Stroke Patient With Low Initial Alberta Stroke Program Early CT Score (ASPECTS) Following Endovascular Thrombectomy: A Case Report.

According to current American and European guidelines, mechanical thrombectomy is recommended only for patients with an Alberta Stroke Program Early CT Score (ASPECTS) of 6 or higher. However, recent literature suggests that the potential benefits of reperfusion therapy should not be solely determined by baseline ASPECTS. In this case report, we present a young female patient with a low initial ASPECTS (4-5), who underwent mechanical thrombectomy and showed marked improvement in both CT imaging and clinical symptoms. Our findings potentially show that mechanical thrombectomy may be beneficial even for patients with an initial ASPECTS ≤ 5. These results may contribute to the growing evidence supporting the use of mechanical thrombectomy as a viable treatment option for acute ischemic stroke patients with low baseline ASPECTS.

Under (back) pressure: Better collateral flow may facilitate clot removal in ischemic stroke: A systematic review and meta-analysis.

BACKGROUND: Collateral status may facilitate clot removal and affect rates of successful reperfusion following endovascular therapy (EVT) for acute ischemic stroke (AIS). METHODS: Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Scopus, Web of Science, and Embase. Papers which focused on collateral status and patients treated with EVT for AIS were included in our analysis. Outcomes of interest included collateral score grading, rates of successful reperfusion defined as thrombolysis in cerebral infarction (TICI) score 2b-3 and onset to revascularization time. We calculated pooled odds ratio (OR) or mean difference (MD) and their corresponding 95% confidence intervals (CI) based on collateral status. RESULTS: 16 studies, with 6073 patients, were included in our analysis. Among the included studies, there were six different collateral grading scales, which were dichotomized into "good to moderate" and "poor" collaterals. Odds of successful reperfusion were significantly higher among patients with good to moderate collateral circulation compared to those with poor collaterals (OR = 1.61; 95% CI = 1.24 to 2.09; P-value < 0.001); however, there was heterogeneity among included studies (I2 = 5 4%; P-value = 0.008). Onset to revascularization time was comparable between patients with good to moderate collateral circulation compared to those with poor collaterals (MD = 3.91 min; 95% CI = -8.71 to 16.53; P-value = 0.544); however, there was heterogeneity among included studies (I2= 60%; P-value = 0.014). CONCLUSIONS: The presence of good collaterals may increase the odds of achieving successful reperfusion following EVT for AIS. Improved collateral flow was associated with improved angiographic outcomes, although future work is needed to determine if a causal relationship exists.

A novel predictor in endovascular treatment patients for cerebral perfusion and prognosis: CHA2DS2-VASC.

OBJECTIVE: Thrombolysis in Cerebral Infarction(TICI) score is used to objectively evaluate cerebral perfusion after intervention in acute stroke with mechanical thrombectomy. In our study, we aimed to compare the results of patients with successful TICI perfusion score (TICI ≥ 2c) with the results of patients with poor TICI perfusion score (TICI < 2c) and to investigate the relationship of the CHA2DS2-VASc scoring system with the final TICI perfusion score and other endpoints. METHODS: For this retrospective, single-center, cross-sectional study, 278 patients who underwent endovascular thrombectomy were screened consecutively by the interventional neurology department of hospital. The primary endpoint of the study was in-hospital and 1-year all-cause death. All patients underwent cranial imaging to evaluate hemorrhagic transformation after the procedure. RESULTS: It was observed that CHA2DS2-VASc score was significantly higher in the poor cerebral perfusion group than in the succesful cerebral perfusion group (3.19 ± 1.8 vs 2.72 ± 1.73, p = 0.046). According to Kaplan Meier's analysis, a significant difference was observed in the group with a CHA2DS2-VASc score > 2.5 in terms of all-cause mortality at follow-up compared to the group with a low CHA2DS2-VASc score (p = 0.002). According to Kaplan Meier's analysis, a significant difference was observed in the group with a poor TICI score compared to the group with a succesful one in terms of all-cause mortality at follow-up (p < 0.001). Cox regression model showed that poor TICI score group, Age ≥ 75 years, lower glomerular filtariton rate (GFR), higher high-sensitiveC-reactiveprotein (Hs-CRP), and higher admission NIHSS score were independent predictors of 1-year all-cause mortality. CONCLUSION: High CHA2DS2-VASc score has been shown to be a predictor of unsuccessful cerebral perfusion score and 1-year mortality after mechanical thrombectomy in stroke patients. As a result of our research, it has been shown that complete or nearly complete reperfusion has more positive results than partial reperfusion.

External validation of TICI-ASPECTS-glucose score as a predictive model for symptomatic intracranial hemorrhage following mechanical thrombectomy.

INTRODUCTION: The indication for mechanical thrombectomy for acute ischemic stroke (AIS) secondary to large vessel occlusion has substantially increased in the past few years, but predictors of symptomatic intracranial hemorrhage (sICH) remain largely unstudied. A recent study assessing these predictors, led to the development of the TICI-ASPECTS-glucose (TAG) score, an internally validated model to predict sICH following thrombectomy. METHODS: To externally validate this scoring system and identify other potential risk factors for hemorrhagic conversion following endovascular therapy for AIS, 420 consecutive patients treated with mechanical thrombectomy from 2014-2017 were retrospectively reviewed. Data were collected pertaining to admission factors, procedural metrics, and functional outcomes. The components comprising the TAG score consist of modified thrombolysis in cerebral infarction (mTICI) score (mTICI 0-2a=2 points; 2b-3=0 points), Alberta stroke program early CT (ASPECTS) score (<6=4 points, 6-7=2 points, ≥8=0 points), and glucose (≥150 mg/dL=1 point, <150 mg/dL=0 points). Statistical analyses including univariate analysis, logistic regression analysis, and area under the receiver-operating curve (AUROC) were performed to validate the predictive capability of the model. RESULTS: The patients with sICH presented with lower ASPECTS (8.13±1.55 v 9.16±1.24, p < 0.001), but no significant correlation with mTICI scores and admission glucose was observed. Decreasing ASPECTS correlated with increased risk of sICH (OR 1.57, 95% CI 1.25-1.96, p < 0.001), and increasing TAG score was associated with increased sICH (OR 1.46, 95% CI 1.11-1.94, p < 0.01). AUROC of the model was 0.633. Stratifying patients into low (TAG 0-2), intermediate,3,4 and high5-7 risk groups identified similar results to the original study with sICH risks of 5.2%, 10.5%, and 33.3%, respectively. CONCLUSION: The TICI-ASPECTS-glucose (TAG) score adequately predicts sICH following mechanical thrombectomy, and appropriately stratifies individual patient risk. Further inclusion of additional predictors of sICH would likely yield a more robust model.

Mechanical Thrombectomy in Acute Ischemic Stroke: Angiographic Predictors of Outcome.

Background: In patients with acute ischemic stroke with large vessel occlusion, various angiographic features are important in patient selection and predicting outcome. Objective: We evaluated angiographic features like collaterals, clot burden score, angiographic recanalization, number of passes, and intracranial atherosclerotic disease (ICAD) with the functional outcome at 90 days. Materials and Methods: This was a retrospective analysis of prospectively collected data of 163 patients with acute ischemic stroke with large vessel occlusion who underwent mechanical thrombectomy within 24 hours of symptom onset. Angiographic data were reviewed blinded to clinical data. The outcome was defined as modified Rankin scale (mRS) at 90 days (good outcome mRS ≤2). Results: The median age of patients was 60 years and 34.4% were females. The median National Institutes of Health Stroke Scale (NIHSS) and Alberta Stroke Programme Early CT Score (ASPECTS) at admission were 17 and 6, respectively. On bivariate analysis, ASPECTS was >6, clot burden score was ≥7, recanalization of TICI was ≥2b, absence of ICAD, showed a positive correlation with the good outcome at 90 days (P-values of 0.003, 0.0001, and 0.03, respectively). Multiple attempts of device passes were associated with poor recanalization (P = 0.001) and it was seen more in ICAD patients. On multivariate analysis, independent predictors of poor outcome were clot burden score <7 (P = 0.043) and TICI score <2b (P = 0.048). Out of 41 patients (26%) with ICAD, 29 had a poor outcome at 90 days. Conclusion: Lower clot burden and less degree of recanalization were associated with poor outcome in acute ischemic stroke due to Large vessel occlusion (LVO). The presence of ICAD also predicted poor outcome.

Favourable collaterals according to the Careggi Collateral Score grading system in patients treated with thrombectomy for stroke with middle cerebral artery occlusion.

The ability of the current grading systems to predict optimal outcomes in stroke patients with favourable collaterals remains unexplored. We evaluated differences in the performance of grading systems between Careggi Collateral Score and ASITN/SIR collateral score to predict clinical and radiological outcomes in stroke patients with favourable collaterals who underwent thrombectomy. We included stroke patients receiving thrombectomy within 360 min after symptom onset with MCA occlusion and favourable collaterals (i.e., without poor collaterals) defined by ASITN/SIR collateral score between 2 and 4. Using ordinal regression, we estimated the association of each CCS and ASITN/SIR grade with mRS shift (0-6) at 3 months, NIHSS score (0-42) and ASPECT score (10-0) at baseline, TICI score (3-0), infarct growth, cerebral bleeding, and cerebral edema grading at 24 h by calculating the odds ratios (ORs) with two-sided 95% confidence intervals after adjustment for predefined variables. Using the best collateral grade (CCS = 4) as reference, ORs of the CCS grades were associated in the direction of unfavourable outcome on 3-month mRS shift (2.325 for CCS = 3; 5.092 for CCS = 2), in the direction of more severe baseline NIHSS score (5.434 for CCS = 3; 16.041 for CCS = 2), 24-h infarct growth (2.659 for CCS = 3; 8.288 for CCS = 4) and 24-h cerebral edema (1.057 for CCS = 3; 5.374 for CCS = 2) shift. ORs of the ASITN/SIR grades were associated in the direction of more severe baseline NIHSS score (4.332 for ASITN/SIR = 3; 16.960 for ASITN/SIR = 2) and 24-h infarct growth (2.138 for ASITN/SIR = 3; 7.490 for ASITN/SIR = 2) shift. The AUC ROC of CCS and ASITN/SIR for predicting 3-month mRS score 0-1 were 0.681 (95% CI: 0.562-0.799; p = 0.009) and 0.599 (95% CI: 0.466-0.73; p = 0.156), respectively. CCS = 4 and ASITN/SIR ≥ 3 were the optimal cut-offs to predict 3-month mRS score 0-1, respectively. CCS grading system performed better than the ASITN/SIR collateral score predicting 3-month mRS score and 24-h CED grading in stroke patients with favourable collaterals who received thrombectomy for MCA occlusion.

Safety and Efficacy of the Novel Low-Profile APERIO Hybrid17 for a Treatment of Proximal and Distal Vessel Occlusion in Acute Ischemic Stroke: A Multi-Center Experience.

OBJECTIVE: To report our initial experience with the novel low-profile APERIO Hybrid17 Thrombectomy Device (AP17) for proximal and distal vessel occlusions in acute ischemic stroke. METHODS: A multicentric retrospective analysis of patients treated with the AP17 was performed. The primary effectiveness endpoint was first-pass TICI ≥2b (Thrombolysis in cerebral infarction scale). The primary safety endpoint was the occurrence of hemorrhagic complications. Further outcome measures were number of passes, device-related complications, and 3-month functional outcome. RESULTS: The AP17 was used in 71 patients (mean age: 73 years) with a median baseline National Institutes of Health Stroke Scale score of 9. Treated vessels were the carotid-T in 8 cases (11%), the M1-segment in 16 (23%), the M2-segment in 29 (41%), the anterior cerebral artery in 3 (4%), and basilar/posterior cerebral arteries in 15 (21%). The rates of first-pass and final TICI ≥2b were 75.6% and 92.7%, retrospectively, with a mean number of passes of 3 ± 2. Final TICI ≥2b rates were comparable between large and medium vessel occlusions. Symptomatic intracranial hemorrhages were recorded in 2 cases (2.8%). At 3-month clinical follow-up, a modified Rankin scale score ≤2 was achieved in 69.0% (29/42). The all-cause mortality at discharge was 17.4%. CONCLUSIONS: The AP17 was associated with a reasonable safety and efficacy profile for both proximal and distal vessel occlusions. These results may contribute to establish mechanical thrombectomy for distal occlusions.

Predictors of Radiographic and Symptomatic Hemorrhagic Conversion Following Endovascular Thrombectomy for Acute Ischemic Stroke Due to Large Vessel Occlusion.

Background Endovascular therapy is known to achieve a high rate of recanalization in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) and is currently the standard of care. Hemorrhagic conversion is a severe complication that may occur following AIS in patients undergoing endovascular thrombectomy (EVT). There is a scarcity of data on the risk factors related to HV in post-EVT patients, especially those who develop symptomatic hemorrhagic conversion. The main objective of our study is to identify independent predictors of radiographic and symptomatic hemorrhagic conversion in our diverse patient population with multiple baseline comorbidities that presented with AIS and were treated with EVT as per the most updated guidelines and practices. Methodology This is a retrospective chart review in which we enrolled adult patients treated with EVT for AIS at a comprehensive stroke center in the Bronx, NY, over a four-year period. Bivariate analyses followed by multiple logistic regression modeling were performed to determine the independent predictors of all and symptomatic hemorrhagic conversion. Results A total of 326 patients who underwent EVT for AIS were enrolled. Of these, 74 (22.7%) had an HC, while 252 (77.3%) did not. In total, 25 out of the 74 (33.7%) patients were symptomatic. In the logistic regression model, a history of prior ischemic stroke (odds ratio (OR) = 2.197; 95% confidence interval (CI) = 1.062-4.545; p-value = 0.034), Alberta Stroke Program Early CT Score (ASPECTS) of <6 (OR = 2.207; 95% CI = 1.477-7.194; p-value = 0.019), and Thrombolysis in Cerebral Infarction (TICI) 2B-3 recanalization (OR = 2.551; 95% CI = 1.998-6.520; p-value=0.045) were found to be independent predictors of all types of hemorrhagic conversion. The only independent predictor of symptomatic hemorrhagic conversion on multiple logistic regression modeling was an elevated international normalized ratio (INR) (OR = 11.051; 95% CI = 1.866-65.440; p-value = 0.008). Conclusions History of prior ischemic stroke, low ASPECTS score, and TICI 2B-3 recanalization are independent predictors of hemorrhagic conversion while an elevated INR is the only independent predictor of symptomatic hemorrhagic conversion in post-thrombectomy patients.

Evaluation of challenges and limitations of mechanical thrombectomy using 3D printed neurovascular phantoms.

The mechanical thrombectomy (MT) efficacy, for large vessel occlusion (LVO) treatment in patients with stroke, could be improved if better teaching and practicing surgical tools were available. We propose a novel approach that uses 3D printing (3DP) to generate patient anatomical vascular variants for simulation of diverse clinical scenarios of LVO treated with MT. 3DP phantoms were connected to a flow loop with physiologically relevant flow conditions, including input flow rate and fluid temperature. A simulated blood clot was introduced into the model and placed in the Middle Cerebral Artery region. Clot location, composition (hard or soft clot), length, and arterial angulation were varied and MTs were simulated using stent retrievers. Device placement relative to the clot and the outcome of the thrombectomy were recorded for each situation. Angiograms were captured before and after LVO simulation and after the MT. Recanalization outcome was evaluated using the Thrombolysis in Cerebral Infarction (TICI) scale. Forty-two 3DP neurovascular phantom benchtop experiments were performed. Clot mechanical properties, hard versus soft, had the highest impact on the MT outcome, with 18/42 proving to be successful with full or partial clot retrieval. Other factors such as device manufacturer and the tortuosity of the 3DP model correlated weakly with the MT outcome. We demonstrated that 3DP can become a comprehensive tool for teaching and practicing various surgical procedures for MT in LVO patients. This platform can help vascular surgeons understand the endovascular devices limitations and patient vascular geometry challenges, to allow surgical approach optimization.

Acute symptomatic seizures and epilepsy after mechanical thrombectomy. A prospective long-term follow-up study.

INTRODUCTION: New treatments for acute ischaemic stroke, such as mechanical thrombectomy, can achieve reperfusion of large ischaemic tissue. Some studies have suggested that reperfusion therapies can increase the risk of suffering acute symptomatic seizure (ASS) and poststroke epilepsy (PSE). The aim of the study was to determine the incidence of ASS and PSE in patients undergoing thrombectomy, and related factors. PATIENTS AND METHODS: This was a retrospective single-centre study including patients with ischaemic stroke and NIHSS> 8 treated with thrombectomy with a follow-up ≥5 years. We evaluated several epidemiological, radiological, clinical and electroencephalographic variables. RESULTS: Of the 344 included patients, 21 (6.1%) presented ASS, 53 (15.40%) died in the acute phase, and 13 (4.46%) died during the first year. The degree of reperfusion (p 0.029), advanced age (p 0.035), and haemorrhagic transformation (p 0.038) increased the risk of suffering ASS, with degree of reperfusion being an independent factor, OR 2.02 (1.21-4.64). The incidence of PSE was 4.12% in the first year, 3.72% in the second, and 1.61% in the fifth. The accumulated incidence at 5 years was 8.93%. Related risk factor for suffering PSE was ASS (p < 0.001), yielding an OR value of 2.00 (1.28-3.145). CONCLUSIONS: Thrombectomy doesn´t increase the risk of ASS. A higher percentage of reperfusion, advanced age, and haemorrhagic transformation are associated with an increased risk of ASS. ASS is a risk factor for suffering PSE. In terms of mortality, having suffered ASS and/or PSE does not increase acute or long-term mortality.

Use of biplane quantitative angiographic imaging with ensemble neural networks to assess reperfusion status during mechanical thrombectomy.

Digital subtraction angiography (DSA) is the main imaging modality used to assess reperfusion during mechanical thrombectomy (MT) when treating large vessel occlusion (LVO) ischemic strokes. To improve this visual and subjective assessment, hybrid models combining angiographic parametric imaging (API) with deep learning tools have been proposed. These models use convolutional neural networks (CNN) with single view individual API maps, thus restricting use of complementary information from multiple views and maps resulting in loss of relevant clinical information. This study investigates use of ensemble networks to combine hemodynamic information from multiple bi-plane API maps to assess level of reperfusion. Three-hundred-eighty-three anteroposterior (AP) and lateral view DSAs were retrospectively collected from patients who underwent MTs of anterior circulation LVOs. API peak height (PH) and area under time density curve (AUC) maps were generated. CNNs were developed to classify maps as adequate/inadequate reperfusion as labeled by two neuro-interventionalists. Outputs from individual networks were combined by weighting each output, using a grid search algorithm. Ensembled, AP-AUC, AP-PH, lateral-AUC, and lateral-PH networks achieved accuracies of 83.0% (95% confidence-interval: 81.2%-84.8%), 74.4% (72.0%-76.7%), 74.2% (72.8%-75.7%), 74.9% (72.2%-77.7%), and 76.9% (74.4%-79.5%); area under receiver operating characteristic curves of 0.86 (0.84-0.88), 0.81 (0.79-0.83), 0.83 (0.81-0.84), 0.82 (0.8-0.84), and 0.84 (0.82-0.87); and Matthews correlation coefficients of 0.66 (0.63-0.70), 0.48 (0.43-0.53), 0.49 (0.46-0.52), 0.51 (0.45-0.56), and 0.54 (0.49-0.59) respectively. Ensembled network performance was significantly better than individual networks (McNemar's p-value<0.05). This study proved feasibility of using ensemble networks to combine hemodynamic information from multiple bi-plane API maps to assess level of reperfusion during MTs.

Iatrogenic intracranial vessel dissection during mechanical thrombectomy rescued by emergent stenting: 2 case reports.

Intracranial vessel dissection is a procedural complication associated with endovascular treatment. However, there have been few reports on its potential causes and management during mechanical thrombectomy. In approximately 250 cases of mechanical thrombectomy over the past 5 years at our institution, iatrogenic intracranial dissection occurred in 2 patients (0.8%). In this report, we described these 2 cases that were rescued through emergent stenting. Mechanical thrombectomy, using both a stent retriever and an aspiration catheter, was performed for acute middle cerebral artery M2 occlusion in Patient 1 (a 69-year-old man) and for distal M1 occlusion in Patient 2 (an 83-year-old woman). In both cases, recanalization was achieved with the procedure, but irregular stenosis developed at the initially nonoccluded, but mildly arteriosclerotic, M1, after recanalization. During the thrombectomy procedure, the aspiration catheter sifted up to the arteriosclerotic M1. In both cases, the lesions were considered vessel dissection, due to a shift of the aspiration catheter tip into the arteriosclerotic vessel wall. Repeated percutaneous angiography with antithrombotic therapy failed to improve the lesions and to maintain the antegrade blood flow. Finally, lesions in each patient were successfully rescued through the use of emergent stenting. A drug-eluting stent for coronary use was deployed in Patient 1, and an Enterprise stent was applied in Patient 2. Inadvertent shift of the aspiration catheter into arteriosclerotic vessels can cause a serious intracranial vessel dissection. When performing mechanical thrombectomy, intracranial stents need to be available as rescue treatment devices to manage refractory iatrogenic intracranial vessel dissection.

Favorable outcome of repeat mechanical thrombectomy in a geriatric patient: illustrative case.

BACKGROUND: The authors presented their experience with a case of repeat thrombectomy in a 93-year-old patient who showed a favorable outcome after recurrent large vessel occlusion treated with emergency mechanical thrombectomy. OBSERVATIONS: Mechanical thrombectomy has been proven to be effective in treating large vessel occlusion types of ischemic stroke. Most of the patient populations involved in the thrombectomy-related studies were younger than 80 years. In addition, recurrent mechanical thrombectomy is not a common procedure in clinical practice. This unusual case demonstrated the potential to achieve a favorable outcome with thrombectomy even in a patient older than 85 years with recurrent large vessel occlusion. LESSONS: There can be a favorable neurological outcome after one or repeat thrombectomies for geriatric patients older than 90 years, and age should not be a deterrent to treatment.

Vascular occlusion in a previously unaffected territory after treatment with intravenous plasminogen activator: illustrative case.

BACKGROUND: Intravenous tissue plasminogen activator (IV t-PA) is effective for the treatment of distal artery occlusion. However, after the use of IV t-PA, vascular occlusion in unaffected territories may occur. Early recurrent ischemic stroke (ERIS) is defined as the occurrence of new neurological symptoms that suggest the involvement of initially unaffected vascular territories after intravenous thrombolysis (IVT). The authors reviewed the cases of ERIS that occurred within 24 hours after treatment with IVT. OBSERVATIONS: A 75-year-old woman with occlusion in the M2 segment of the left middle cerebral artery (MCA) was treated with IV t-PA. However, 360 minutes later, the patient presented with occlusion in the M1 distal segment of the contralateral side, the right MCA, which was recanalized by endovascular treatment. Her modified Rankin Scale score was 4; however, aphasia was not observed. She was transferred to a rehabilitation hospital after 3 months. LESSONS: ERIS is an extremely rare but catastrophic event. The underlying mechanism of ERIS most likely involves the disintegration and subsequent scattering of a preexisting intracardiac thrombus. Hence, caution must be used when managing not only hemorrhagic complications but also ischemic complications after IV t-PA. Endovascular management may be the only effective treatment for this type of large vessel occlusion.

Mechanical Thrombectomy with the Novel NeVa M1 Stent Retriever: Do the Drop Zones Represent a Risk or a Benefit?

OBJECTIVE: The NeVa M1 thrombectomy device is a novel hybrid-cell stent retriever with multifunctional zones for optimized retrieval of resistant clots located in the M1 segment of the middle cerebral artery. The objective was to evaluate the safety and efficacy of the NeVa in a "real-life" setting. METHODS: Twenty-nine consecutive patients (median age: 77 years) treated with the NeVa M1 for acute ischemic stroke of the M1 segement were retrospectively reviewed. First-pass and final modified thrombolysis in cerebral infarction (mTICI) scores, device-related complications, symptomatic intracranial hemorrhage, and 90-day modified Rankin scale (mRS) scores are reported. Primary outcome parameters were first-pass mTICI 2b-3 reperfusion and mRS 0-2 at 90 days. RESULTS: Median National Institutes of Health Stroke Scale scores decreased from 16 to 12 after treatment. mTICI 2b-3 reperfusion rates were 55% after the first pass, 79% after 1-2 passes, and 100% after the final pass. mTICI 2c-3 was obtained in 48% after the first pass, 62% after 1-2 passes, and 72% after the final pass. Rescue treatment was performed in 4 patients (14%). Device-related complications included 1 asymptomatic caroticocavernous fistula, 1 asymptomatic M2 dissection, and 1 symptomatic intracranial hemorrhage. The procedure-related vasospasm rate was 48%. A 90-day mRS of 0-2 was achieved by 31%. CONCLUSIONS: The NeVa M1 provides a high first-pass complete reperfusion rate with an adequate safety profile. To retrieve resistant clots, the stent design exerts high mechanical traction forces, which may trigger vasospasm and vessel wall damage. Large, comparative studies are warranted to draw a definite conclusion on this device.

An Observational Study Investigating the Need for Decompressive Hemicraniectomy after Thrombectomy in Acute Ischemic Stroke of the Middle Cerebral Artery Territory.

OBJECTIVE: The frequency incidence of decompressive hemicraniectomy following intra-arterial thrombectomy (IAT) in acute ischemic stroke (AIS) involving the middle cerebral artery (MCA) territory was assessed as a surrogate for morbidity. METHODS: A single-institution retrospective chart review was conducted involving 209 consecutive patients between September 2014 and May 2017 with infarctions affecting the MCA territory and who subsequently underwent IAT. The outcomes of interest included the frequency of hemicraniectomy following IAT and the effects of intravenous tissue plasminogen activator (IV tPA) use and primary occlusion site on the Thrombolysis in Cerebral Infarction (TICI) score. RESULTS: Thirty-one patients were excluded for infarctions not involving the MCA territory. A total of 178 patients were included in the study. Sixty-eight patients (38.6%) had infarctions of less than one-third of the MCA territory, 50 (28.4%) had infarctions between one-third and two-thirds, and 58 (33%) had infarctions involving greater than two-thirds with 54.3% suffering infarctions of the left side. Only four patients (2.2%) required a hemicraniectomy with no statistically significant association found between TICI score and hemicraniectomy (p=0.41) or between administration of IV tPA and hemicraniectomy (p=0.36). The primary occlusion site was found to influence TICI score (p=0.045). CONCLUSION: A very small number of patients required hemicraniectomy after IAT as compared to previously published rates in the literature. However, several factors may prevent the patient from being an appropriate hemicraniectomy candidate in the first place and the small number of these patients in this study limits statistical analysis. The variables that determine a patient's candidacy for decompressive hemicraniectomy remains multi-factorial.

Recent advances in devices for mechanical thrombectomy.

INTRODUCTION: Acute ischemic stroke (AIS) secondary to the occlusion of a large intracranial vessel (LVO) is a recognized public health problem. Mechanical thrombectomy (MT) has gained full acceptance: Class A, Level 1 in 2015 after the publication of numerous trials. Further meta-analyses have scrutinized extensively those results and international recommendations and guidelines have been given. Nevertheless, multiple-specific points remain to be clarified and are or will be under investigations. AREAS COVERED: This review of the most recent literature (mostly publications after 2015) will cover the actual common practice for MT, especially focusing on the devices available (and their validation), how they are commonly used, relate the most relevant results, and detail some emerging technologies. EXPERT OPINION: The authors will express their own view on the current practice and emphasize on the areas where questions remain and hypothesize what specific improvements are necessary and prone to occur.