Mechanical Thrombectomy For Occlusion Research Articles

Comparative Analysis of Mechanical Thrombectomy Outcomes of Middle Cerebral Artery M1, M2 Superior, and M2 Inferior Occlusion Strokes

BackgroundThe M1 middle cerebral artery (MCA) commonly bifurcates into an M2 superior and an M2 inferior segment. However, MCA anatomy is highly variable rendering classification for mechanical thrombectomy (MT) trials difficult. Safety and effectiveness of M2 MCA stroke thrombectomy stratified by M2 MCA anatomy remains to be explored. MethodsLarge vessel occlusion strokes undergoing MT between 02/2016-08/2022 were reviewed (n=784). M1 (n=431) and M2 MCA (n=118) occlusions were assessed. Among M2 MCA occlusions only prototypical MCA bifurcation anatomy cases were included (n=99). Dominance was assessed based on angiography. Procedural and outcome data was compared between M1, M2 superior and M2 inferior MCA occlusions. ResultsBaseline demographics and periprocedural criteria of M2 superior (n=56) and M2 inferior (n=43) occlusion MTs were comparable. Among M2 inferior cases, the occluded branch was dominant in 41/43 (95.3%) but only in 37/56 (66.1%) among M2 superior cases (p<0.001). The 90-day favorable functional outcome (mRS 0-2) and mortality (mRS 6) rates were 60.0% and 8.9% in the M2 superior, 42.9% and 32.6% in the M2 inferior, and 44.1% and 26.0% in the M1 group (n=431). Compared to M2 superior, M2 inferior favorable outcome rates were lower (p=0.094) and mortality rates were higher (p=0.003) and resembled M1 outcome rates (p=0.750 and p=0.355, respectively). ConclusionIn setting of prototypical MCA bifurcation anatomy, thrombectomy of dominant M2 inferior occlusions had outcome rates like M1 occlusions. In contrast, M2 superior occlusions had significantly lower mortality rates and a trend towards better favorable functional outcome rates.

Abstract TP135: Age-Related Differences in DWI Lesion Volume and Reversal in Patients With Recanalization After Mechanical Thrombectomy for Large Vessel Occlusion

Background and Purpose: With the development of mechanical thrombectomy (MT) for large vessel occlusion (LVO), post-treatment DWI lesion reversal (DWIR) has been reported. We aimed to retrospectively compare baseline and post-treatment DWI lesion volume and the incidence of DWIR between younger and elderly patients who received successful recanalization by MT for anterior LVO. Methods: A total of 177 patients who underwent successful recanalization with MT for occlusion of the anterior LVO between April 2011 and September 2022 were included in our hospital. Patients were divided into two groups: under 70 years of age and over 70 years of age. MRI was performed before and 24 hours after treatment. DWI lesion volume, apparent diffusion coefficient (ADC) value of DWI lesion, and the incidence of DWIR were examined between age groups. Factors associated with DWI lesion volumes were determined by multivariate analysis. Result: The median age of the patients was 78 years, 76 (42.9%) were female, 35 (19.8%) were in the &lt;70 years group, and 142 (80.2%) were in the ≥70 years group. No significant differences existed between the age groups in the distribution of occluded vessels, NIHSS, and time from onset to recanalization. Baseline volume was significantly higher in the &lt;70 years group than in the ≥70 years group (16.0ml vs 4.0ml p&lt;0.001). There was no difference in the ADC value of DWI lesion between the two groups. There was no difference in DWIR between the two groups (65% vs. 55%), but the post-treatment DWI lesion was significantly smaller than the baseline lesion n the &lt;70 years group. was Age being also independent of DWI lesion volume before and after treatment. Conclusions: In patients undergoing recanalization on MT for anterior LVO, baseline DWI lesions were significantly larger in young patients than in elderly patients. Although DWIR was present in over half of both groups, DWI lesion volume was significantly reduced after recanalization in younger patients.

Evaluation of effectiveness and safety of the large-format pRESET 6-50 thrombectomy stent-retriever in the endovascular treatment of ischemic stroke: real-world experiences from two tertiary comprehensive stroke centers.

Mechanical thrombectomy (MT) has become the standard treatment for acute ischemic stroke (AIS) with large vessel occlusion (LVO). First-pass (FP) reperfusion of the occluded vessel and fewer passes with stent retrievers show improvement in functional outcomes in stroke patients, while higher numbers of passes are associated with higher complication rates and worse outcomes. Studies indicate that a larger size of the stent-retriever is associated with a higher rate of first-pass reperfusion and improved clinical outcomes. In this retrospective study, we investigated the clinical performance of a recently developed and one of the largest stent-retrievers available in the treatment of LVO (pRESET 6-50, phenox GmbH, Bochum). All consecutive patients with ischemic stroke due to proximal large vessel occlusion treated with MT using the pRESET 6-50 stent-retriever in two tertiary stroke centers between 09/2021 and 07/2022 were included in this study. The reperfusion rate after MT was quantified by the modified thrombolysis in cerebral infarction (mTICI) score, and functional neurological outcome was evaluated with the National Institutes of Health Stroke Scale (NIHSS) score and the major early neurological recovery (mENR) rate after 24 h. Successful FP reperfusion was defined as mTICI ≥ 2b. Successful and complete reperfusion were defined as mTICI ≥ 2b and mTICI ≥ 2c, respectively. In total, 98 patients (52 men and 46 women) with a median age of 75 (range 25-95 years) were included. A total of 70 (72%) patients presented with an occlusion of the middle cerebral artery (MCA) in the M1 segment, 6 (6%) patients with an occlusion of the M2 segment, 17 (17%) patients with an occlusion of the internal carotid artery (ICA), and 5 (5%) patients with an occlusion of the obstructed basilar artery (BA). Successful FP reperfusion was achieved in 58 patients (62%). Successful and complete reperfusion were achieved in 95 (97%) and 82 (83%) patients, respectively. The median National Institutes of Health Stroke Scale (NIHSS) in all treated patients improved from 17 to 7.5. Major early neurological recovery (mENR) was observed in 34 patients (35.1%). MT with the pRESET 6-50 stent-retriever achieves high successful first-pass and final reperfusion rates in patients with AIS and LVO. The results of this study support the thesis to use large-format stent-retriever in proximal vessel occlusion MT whenever feasible in order to improve high FP and final reperfusion rate, which are known predictors of good clinical outcome.

Abstract 211: Comparing Early and Late Window 3mm Trevo Stent Retriever Performance in Medium Vessel Occlusion Thrombectomy

Introduction Endovascular thrombectomy has been shown to be beneficial for select patients with medium vessel occlusion ischemic strokes. Newer mechanical thrombectomy devices have designs to facilitate navigation of the medium and distal cerebrovasculature. In this single‐center study, we aim to compare the performance of 3mm Trevo NXT stent retrievers (Stryker, Kalamazoo, MI) for medium vessel occlusion mechanical thrombectomy for patients treated within either the early (&lt;6 hour) or late (&gt;6 hour) treatment window. Methods A retrospective review was conducted of acute ischemic stroke patients with medium vessel occlusions (i.e., M2‐M4, ACA, and PCA) who underwent thrombectomy over 5 years (2018‐2022) at a single comprehensive stroke center. Classification into early or late window was defined as time from last known well to groin puncture less than 6 hours or greater than 6 hours, respectively. Primary efficacy outcome included successful recanalization (modified thrombolysis in cerebral infarction [mTICI]&gt;=2B) using 3mm Trevo NXT on either first pass or rescue pass (i.e., after initial pass failure with another device). Primary safety outcome is rate of complications associated with the stent retriever. Primary clinical outcome was National Institutes of Health Stroke Scale (NIHSS) shift between admission and discharge. Results Of 81 patients with medium vessel occlusion ischemic strokes, 38 patients (44.7% female, median age of 73.5 years [IQR 66‐82], median initial NIHSS 13 [IQR 8‐23]) underwent thrombectomy with 3mm Trevo NXT. Stent retriever‐assisted aspiration (versus stent retriever only) was performed in 31/38 (81.6%) patients. Successful recanalization with stent retriever was achieved in 28/38 (73.7%) of patients. There was no significant difference in rate of recanalization between early and late window thrombectomy (16/22 [72.7%] early window vs. 12/16 [75%] late window, p=0.8752). The lack of significant difference in recanalization rate was consistent with stent retriever use during first pass (11/14 [78.6%] early window vs. 9/10 [90%] late window, p=0.6146) and as rescue (5/8 [62.5%] early window vs. 3/6 [50%] late window, p=0.6400). There was no significant difference in the rate of stent retriever complications between early and late windows (1/16 [6.3%] early vs. 0/22 [0%] late, p=0.4211). There was no significant difference in median NIHSS shift from admission to discharge ( ‐6 [IQR ‐16 ‐ 9] early window vs. ‐3 [IQR ‐5 ‐ 4] late window, p=0.3666). Conclusion In both early and late window medium vessel occlusion thrombectomy, the 3mm Trevo NXT as first line and rescue intervention performs comparably and adequately. Future multicenter studies will further characterize novel stent retriever performance in medium vessel occlusion thrombectomies.

Management and prognosis of acute extracranial internal carotid artery occlusion.

Acute occlusion of the internal carotid artery is the underlying etiology in 4 to 15% of all ischemic strokes. The clinical presentation varies considerably ranging from asymptomatic occlusion to severe ischemic strokes. Substantial differences in the acute management of acute symptomatic internal carotid artery occlusions (ICAO) exists between centers. Thusly, we comprised a narrative review of the natural course of acute ICAO and of available treatment options [i.v. thrombolysis, endovascular thrombectomy and stenting, bypass between the superficial temporal and the middle cerebral arteries (MCA) and carotid endarterectomy (CEA)]. We found that very few randomized treatment trials have been performed in patients acute symptomatic ICAO. Most evidence stems from case series and observational studies. Especially in older studies the intracranial vessel status has rarely been considered. After revision of these studies we concluded that the mainstay of the acute management of acute symptomatic ICAO is i.v. thrombolysis when applied within the label and in combination with mechanical thrombectomy in case of intracranial large vessel occlusion. In cases without intracranial large vessel occlusion mechanical thrombectomy of acute ICAO is associated with a risk of distal embolization. More research on prognostic parameters is needed to better characterize the risk of decompensation of collateral flow and to better define the time-window of intervention. When mechanical thrombectomy fails or is not available, surgical approaches are an alternative in selected patients.

Abstract 107: Real World Clinical and Radiographic Outcomes With and Without Intravenous tPA in Anterior Circulation Large Vessel Occlusion Mechanical Thrombectomy Patients Treated Within 8 Hours

Background and Aims: Intravenous tPA remains the standard of care, with MT currently indicated within 8 hours for IV tPA failures or patients with IV tPA contraindications. Whether LVO patients should receive IV tPA treatment or instead be triaged directly to MT therapy is currently unknown but greatly debated. The Trevo Registry is a real world, multi-center, international study of mechanical thrombectomy (MT) patients treated from 0-24 hours. Evaluation of the Trevo Registry clinical and procedurals outcomes of MT patients treated with or without IV tPA could provide insight into the benefit of IV tPA in MT patients. We hypothesized that in MT patients treated within 8 hours, pretreatment with intravenous tPA would lead to better clinical outcomes compared to patients who did not receive IV tPA. Method: Consecutively enrolled patients treated within 8 hours with ICA, M1, or M2 occlusions were selected for analysis. Univariate and multivariable regressions were conducted to identify clinical and radiographic independent variables that correlate best with the dependent variable of functional outcome: mRS 0-2, with a focus on intravenous tPA treatment. Results: A total of 1183 Trevo Registry patients (overall enrolled, n=2010) qualified for analysis, of whom 380 were not treated with IV tPA. Demographics were similar, however atrial fibrillation (46.3% vs 27.2%) and previous ischemic stroke (14.1% vs 7.5%) were higher in the no IV tPA group. The median time to treatment was similar (3.8 vs. 3.6 hrs). First pass mTICI ≥ 2B (63.6% vs 66.4%) and final revascularization (91.1% vs 92.8%) were similar between no IV tPA and IV tPA groups.Unadjusted, there were similar rates of functional outcome (90 day mRS 0-2; 60.9% vs. 62.5%). After adjustment, patients who did not receive IV-tPA had similar rates of good outcome (aOR 1.08, 95% CI [0.87-1.34]. P=0.58) as well as reduction (shift) in disability (aOR 1.08, 95% CI [0.87-1.34]. P=0.49). Safety outcomes (mortality, sICH) were similar between both groups. Conclusion: In the Trevo Registry of MT patients treated within 8 hours, patients who did not receive IV tPA had similar endovascular and clinical outcomes as patients pretreated with IV tPA. The added benefit of IV tPA for MT patients should be further investigated.

Abstract WP26: The Effects of Blood Pressure Variation Within 24 Hours of Intracerebral Large Vessel Occlusion Mechanical Thrombectomy and Clinical Outcomes

Introduction: Mechanical thrombectomy (MT) is now the standard of care for acute intracranial large vessel occlusion (LVO). There are currently no established guidelines for post MT blood pressure parameters in LVO patients. Our study examines the influence of blood pressure fluctuation and variation within the first 24 hours on clinical outcomes in post MT LVO patients. Methods: A hospital based stroke registry retrospectively identified 111 consecutive patients undergoing MT for LVO (2012-2015). Blood pressure recordings within the 1st 24 hours post MT were analyzed: Maximum (Max), minimum, median and standard deviation (SD) of the systolic (SBP), diastolic (DBP) and mean arterial pressures (MAP) were calculated individually and as composite aggregates. Good outcomes were defined as National Institute of Health Stroke Scale (NIHSS) improvement of &gt;=10 at discharge and or discharge NIHSS&lt;=2 Poor outcomes were defined as post-MT intracerebral hemorrhagic (ICH) and mortality. Univariate (UV). and multivariate logistic regression (MV) were used to identify effect of blood pressure variation on good and poor outcomes. IBM-SPSS version 21 was used for data analysis. Results: On UV analysis a lesser degree of 24 hour post MT SBP (median 16, IQR (Inter Quartile Range) 13, 23 mmHg, p=0.03) and DBP (Median 10, IQR 8, 12 mmHg p .04) SD were associated with good outcome. Maximum SBP was associated with higher rates of mortality (median 188, IQR 174-195 mmHg, p=0.03) and ICH (median 179, IQR 167-196 mmHg, p=0.05). There is no statistically significant association between Post MT 24 hours DBP or MAP maximum, minimum, median and SD values with associated poor outcomes. On MV, SBP variance and maximum SBP were found to be significantly associated with good outcomes (Odds Ratio (OR) 1.09, 95%CI (Confidence interval) 1 - 1.2, p=0.04) and mortality (OR 1.02, 95%CI 1 - 1.004, p=0.02) respectively. Conclusion: Importance of proper blood pressure regulation within the 1st 24 hours of an LVO MT cannot be understated. To maintain good outcomes after MT, minimizing SBP SD becomes important. With the underlying premise of post cerebral ischemia induced vasomotor dysregulation, controlling Max SBP also decreases ICH and mortality. A prospective study is warranted to reinforce our findings.