Mechanical Thrombectomy For Stroke Research Articles

Rapid identification and prognosis evaluation by dual-phase computed tomography angiography for stroke patients with a large ischemic region in the anterior circulation treated with endovascular thrombectomy

PurposeTo investigate the value of dual-phase head-and-neck computed tomography angiography (CTA) in assessing advantages and risks associated with mechanical thrombectomy for stroke with a large ischemic region in the anterior circulation within 6 h of onset.MethodsWe retrospectively analyzed the data of patients with acute occlusion of the internal carotid artery or middle cerebral artery-M1 segment. Baseline dual-phase CTA was performed for collateral grading using the 4-point visual collateral score (0, 0% filling; 1, >0% and ≤50% filling; 2, >50 and <100% filling; 3, 100% filling). The rates of modified Rankin score (MRS) ≤ 3 at 90 days, any intracranial hemorrhage (ICH) within 48 h, malignant cerebral edema within 24 h, and all-cause 90-day mortality were analyzed.ResultsAmong the 69 study patients, 15, 26, 17, and 11 patients had collateral grades of 0, 1, 2, and 3, respectively. At 90 days, the MRS was ≤3 in 0, 8.33, 29.41, and 36.36% of patients with grades 0, 1, 2, and 3, respectively. ICH incidence was 73.33, 57.69, 29.41, and 18.18% for grades 0, 1, 2, and 3, respectively, while the incidence of malignant brain edema was 100, 76.92, 35.29, and 0%, respectively. All-cause 90-day mortality was 53.33% for grade 0 and 30.77% for grade 1; no deaths occurred at grades 2 and 3.ConclusionCollateral grading based on dual-phase CTA enables simple and rapid preoperative evaluation prior to mechanical thrombectomy for acute anterior-circulation stroke with a large ischemic focus, particularly for patients presenting within the 6-h time window.

Feasibility of super-bore 0.088″ mechanical thrombectomy in M1 vessels smaller than 8 French: Experience in 20 consecutive cases.

Superbore 0.088″ catheters provide a platform for optimizing aspiration efficiency and flow control during stroke mechanical thrombectomy procedures. New superbore catheters have the distal flexibility necessary to navigate complex neurovascular anatomy while providing the proximal support of traditional 8F catheters. The safety and feasibility of Zoom 88™ superbore angled-tip catheters in the middle cerebral artery (MCA) segments smaller than the catheter diameter have not been previously described. Twenty consecutive cases of acute MCA mechanical thrombectomy were retrospectively identified from the senior authors' prospectively maintained Institutional Review Board-approved database, in which the Zoom 88 (Imperative Care, Campbell, CA) catheter was successfully navigated to at least the M1 segment. Patient demographics, procedural details, and periprocedural information were analyzed. Rates and averages (standard errors) are generally reported. The average National Institutes of Health Stroke Scale at presentation and age were 15 ± 2 and 73 ± 3 years, respectively. The M1 and M2 occlusions were evenly distributed. The average M1 measurements before thrombectomy ranged from 2.36 ± 0.07 mm proximally to 2.00 ± 0.11 mm distally, and after thrombectomy, they ranged from 2.34 ± 0.07 mm proximally to 1.97 ± 0.10 mm distally. First-pass modified thrombolysis in cerebral infarction (mTICI) 2C/3 recanalization was achieved in 40% of cases, and final mTICI 2C/3 recanalization was achieved in 90% of cases. A single case of mild vasospasm was managed with verapamil. No hemorrhagic or periprocedural complications were noted. Superbore 0.088″ catheters with flexible distal segments can be safely navigated to the MCA to augment mechanical thrombectomy even when the MCA segment is smaller than the catheter.

Abstract TP205: Intracranial Stenting With Mechanical Thrombectomy in Acute Ischemic Stroke in the United States

Background and Purpose: Large vessel occlusion secondary to intracranial atherosclerotic disease (ICAD-LVO) has an estimated prevalence of 10-30%. Registry-based reports from high volume centers indicate that about 4-7% of mechanical thrombectomy (MT) due to LVO are accompanied with intracranial rescue stenting in the US, yet the trend and utilization of rescue stenting in US is unknown. Methods: Analysis of US National Inpatient Sample of strokes with mechanical thrombectomy with or without concomitant intracranial stenting from October 1st, 2016, to December 31st, 2020, was performed. Patient- and hospital-level characteristics were analyzed. Outcomes included favorable disposition (discharged to home) and in-hospital mortality. Results: Among 68,975 of stroke MT with recorded NIHSS during the study period (51.1% women; mean age, 69.1 [SD, 14.6] years; mean NIHSS score of 15.1 [SD, 7.7]), 1,635 (2.3%) underwent concomitant intracranial stenting (44% women; mean age, 64.8 [SD, 13.7] years; mean NIHSS score of 13.8 [SD, 8.1]). Characteristics associated with intracranial stent utilization were male sex, history of diabetes, hypertension, or chronic kidney disease, absence of atrial fibrillation or CHF, and southern US region. Favorable outcome was achieved in 23.6% of MT with stenting versus 32.3% without stenting (P<0.001). In-hospital mortality occurred in 17.1% of MTs with stenting versus 10.5% without stenting (P<0.001). In multivariable analysis among MTs with concomitant intracranial stenting, favorable outcome was associated with lower presenting NIHSS (OR, 0.91 [95% CI, 0.87-0.95], P<0.001), and absence of DM (OR, 0.41 [95% CI, 0.20-0.85], P<0.01). In-hospital mortality was associated with male sex (OR, 3.08 [95% CI, 1.38-6.87], P=0.005) and concomitant IV lytic administration (OR, 2.45 [95% CI, 1.01-5.96], P=0.02). Conclusions: In US practice, less than 3/100 MT’s are performed with concomitant intracranial stenting which is well below the prevalence of failed thrombectomy rates due to underlying ICAD-LVO. Further studies are needed to improve outcomes in this subset of patients.

Abstract TP172: Rising Trends in Cervical Artery Dissection Admissions: A Nationwide Study From 2005 to 2019

Introduction: A recent regional study suggested an upward trend in the incidence rates of spontaneous cervical artery dissection (sCAD). Utilizing a comprehensive nationwide database, we investigated these trends on a national scale. Method: We analyzed adult patients diagnosed with sCAD in the United States National Inpatient Sample database from 2005 to 2019, employing validated standard ICD-9 and ICD-10 diagnostic codes. By integrating the survey-weighted annual total of CAD cases with annual Census data, we estimated the incidence over the study period. The annualized percentage change (APC) over the study period was estimated using regression models and visually represented with an exponential regression line. Trends were further stratified by sex, age group, and race. Result: From 2005 to 2019, we identified 557,063,391 patients, of whom 125,102 (0.02%) had non-traumatic CAD. The incidence of CAD increased from 10.5 cases per million population in 2005 to 45.5 cases per million population in 2019 ( P < 0.001), revealing a significant increase in admissions with CAD. Regression analysis estimated an APC of 9.6%, with a 95% CI of 8.4% to 10.7% (P < 0.001) (Figure). This upward trend persisted across all strata of sex, age, and race. Conclusion: Our nationwide analysis demonstrates a significant rise in admissions with CAD from 2005 to 2019 across all demographic groups. The change in trend could be attributed to greater disease awareness leading to more frequent coding of CAD diagnoses, and/or to increased use of CT angiogram coinciding with the rise of mechanical thrombectomy for stroke. This underscores CAD's increasing clinical prevalence, warranting further investigation into its causes, prevention, and treatment.

Abstract 278: Patterns of Mechanical Thrombectomy for Stroke Before and After the 2015 Pivotal Trials:5 Years Follow‐up

Introduction The 2015 American Heart Association Guidelines recommended mechanical thrombectomy with stent‐retriever devices. A prior published analysis of national trends after one year in mechanical thrombectomy use and outcomes for stroke before and after publication of the 2015 US guideline update showed improved functional outcomes and lower peri‐procedural mortality. We analyze the national trends in mechanical thrombectomy use and outcomes for stroke five years after publication of the US guideline update. Methods We analyzed the National Inpatient Sample from 2012‐2019. ICD‐9 and ICD‐10 codes identified Ischemic stroke and mechanical thrombectomy patients. Similar to the previous study, discharge to home was the primary efficacy outcome measure in this study since it strongly correlates with mild degree of disability at discharge and 3 months post‐stroke. Safety outcomes include in‐hospital medical complications and mortality. We utilized multivariate logistic regression to assess outcomes. Results From 2012‐2019, 4,003,405 individuals with a diagnosis of ischemic stroke were recorded, 103,605 (2.6%) of which were treated with mechanical thrombectomy, proportionally increased from 4,910/452,905 (1.1%) in 2012 to 26,365/552,780 (4.8%) in 2019. The proportion of endovascular thrombectomy performing hospitals nearly doubled during the study period from 2012 (295/4,378; 6.7%) to 2019 (582/4,568; 12.7%). Odds of a mild disability outcome increased from 16% to 20%, OR 0.65 (0.57, 0.74), while mortality decreased from 15% to 12%, OR 0.69 (0.61, 0.78). Compared with 2012‐2014, the 2015‐2019 cohort showed increased odds of ICH and shock while the odds of DVT, pulmonary embolism, pneumonia, and UTI were significantly lower. The presence of septicemia, shock, and cardiac arrest were unchanged. Conclusion The number of large vessel occlusion stroke patients receiving mechanical thrombectomy treatment in the United States is increasing rapidly each year after the 2015 US guideline update. As the use of mechanical thrombectomy expands, included patients have more medical complications at baseline, but experience fewer complications, peri‐procedural mortality and overall improved outcomes.

2b Or 2c-3? A meta-analysis of first pass thrombolysis in cerebral infarction 2b vs multiple pass thrombolysis in cerebral infarction 2c-3 following mechanical thrombectomy for stroke.

Procedural success following mechanical thrombectomy for acute ischemic stroke is assessed using the thrombolysis in cerebral infarction scale. We conducted a systematic review and meta-analysis to determine whether outcomes differed between first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. We conducted a systematic review of the literature using PubMed, Embase, Scopus, and Web of Science. We included original studies in which outcomes were stratified based on first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. The primary outcome of interest was the rate of modified Rankin Scale 0-2. Secondary outcomes of interest were rates of modified Rankin Scale 0-1, symptomatic intracranial hemorrhage, and mortality. We calculated odds ratios and corresponding 95% confidence intervals. Four studies with 1554 patients were included in the quantitative analysis. Rate of modified Rankin Scale 0-2 (odds ratio = 0.91, 95% confidence interval = 0.70-1.18; P-value = 0.49), modified Rankin Scale 0-1 (odds ratio = 1.21, 95% confidence interval = 0.86-1.71; P-value = 0.27), symptomatic intracranial hemorrhage (odds ratio = 1.36, 95% confidence interval = 0.47-3.98; P-value = 0.57), and mortality (odds ratio = 0.91, 95% confidence interval = 0.67-1.25; P-value = 0.56) did not differ between first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. There was no heterogeneity among included studies for modified Rankin Scale 0-2, modified Rankin Scale 0-1, or mortality; however, there was moderate heterogeneity among studies for symptomatic intracranial hemorrhage (I2 = 53%, P-value = 0.12). Clinical and safety outcomes did not differ between first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. Future prospective studies and clinical trials should determine whether first pass thrombolysis in cerebral infarction 2b is a viable endpoint to thrombolysis in cerebral infarction 2c-3.

Inhalational versus Intravenous General Anesthesia for mechanical thrombectomy for stroke: A single centre retrospective study

BackgroundWhen general anesthesia is used for endovascular thrombectomy (EVT) for acute ischemic stroke (AIS), the choice of anesthetic agents for maintenance remains inconclusive. The different effects of intravenous anesthetic and volatiles agents on cerebral hemodynamics are known and may explain differences in outcomes of patients with cerebral pathologies exposed to the different anesthetic modalities. In this single institutional retrospective study, we assessed the impact of total intravenous (TIVA) and inhalational anesthesia on outcomes after EVT. MethodsWe conducted a retrospective analysis of all patients ≥ 18 years who underwent EVT for AIS of the anterior or posterior circulation under general anesthesia. Baseline patient characteristics, anesthetic agents, intra operative hemodynamics, stroke characteristics, time intervals and clinical outcome data were collected and analyzed. ResultsThe study cohort consisted of 191 patients. After excluding 76 patients who were lost to follow up at 90 days, 51 patients received inhalational anesthesia and 64 patients who received TIVA were analyzed. The clinical characteristics between the groups were comparable. Multivariate logistic regression analysis of outcome measures for TIVA versus inhalational anesthesia showed significantly increased odds of good functional outcome (mRS 0–2) at 90 days (adjusted odds ratio, 3.24; 95% CI, 1.25–8.36; p = 0.015) and a non-significant trend towards decreased mortality (adjusted odds ratio, 0.73; CI, 0.15–3.6; p = 0.70). ConclusionPatients who had TIVA for mechanical thrombectomy had significantly increased odds of good functional outcome at 90 days and a non-significant trend towards decrease in mortality. These findings warrant further investigation with large randomized, prospective trials.

Hypertensive crisis: diagnosis, presentation, and treatment.

Hypertensive crisis (HTN-C) is a condition of increasing prevalence. It carries significant morbidity and mortality, and prompt recognition and treatment are crucial. There is a paucity of controlled trials, so a working knowledge of the most recent literature in the area of HTN-C is helpful. Novel serological markers, including serum corin, have been found to aid in the early identification of end-organ damage from severely elevated blood pressure (BP). In the area of BP following thrombolysis for ischemic stroke, lower target BP (130-140 mmHg) is associated with some improved outcomes. Two large trials of lower BP following mechanical thrombectomy in stroke have failed to show improved outcomes; however, observed data show benefits at lower than currently recommended levels. Clevidipine, a calcium channel blocker marketed for unique use in HTN-C, was found to be noninferior to the generic less expensive nicardipine. Oral nifedipine was found to be the most effective agent for sustained BP reduction in preeclampsia. HTN-C remains an area with few prospective randomized trials, but there is active research on identifying lower goals for specific clinical scenarios. Ideal therapeutic agents should be tailored for specific end-organ damage.

Abstract Number ‐ 155: CT Perfusion May Optimize Selection Of Elderly Patients For Mechanical Stroke Thrombectomy

Introduction Prior studies have demonstrated that CT perfusion (CTP) may be used to select patients for mechanical stroke thrombectomy (MST) with acute ischemic stroke owing to major artery obstruction in the anterior circulation for up to 24 hours. There is limited data on CTP selection of elderly patients aged ≥ 90 years old. We aimed to examine whether selecting nonagenarians with CT perfusion (CTP) imaging would allow for better outcomes. Specifically we aimed to examine hypoperfusion intensity ratio (HIR) and early infarct growth rate (EIGR) to optimize MST selection of nonagenarians. Methods This is a single center retrospective study from a large academic medical center. Patients included were at least 90 years old, presented with an anterior circulation acute ischemic stroke due to large vessel occlusion (LVO) and were treated with mechanical stroke thrombectomy (MST) between January 2018 and April 2022. Patients without CT perfusion (CTP) imaging prior to MST and without complete data were excluded. HIR was defined as time to maximum (Tmax 10 seconds/ Tmax 6 seconds). EIGR was defined as (relative cerebral blood flow < 30% / last known well to CTP). Primary outcome was modified Rankin Scale (mRS) at 90 days, analyzed using an ordinal regression analysis and adjusted for baseline mRS, NIHSS, and possible confounding variables identified in univariate analyses. Secondary outcomes were: excellent reperfusion (TICI ≥ 2C), procedural complications of MST and symptomatic intracranial hemorrhage (sICH). The secondary outcomes were analyzed using binomial logistic regressions in two blocks where confounding variables were entered first, followed by variables of interest: HIR and EIGR. Results During the study epoch 70 nonagenarians were treated with MST. After exclusions, 59 nonagenarians were analyzed in the study. Despite selecting patients with CTP, 35 (59.3%) of patients reached mortality at 90 days. Additionally, only 9 (15.3%) patients achieved mRS of 0 – 2 or baseline mRS (if baseline mRS > 2) at 90 days. HIR was found to be correlated with 90 day mRS (shift to next worse mRS), adjusted odds ratio (aOR) = 14.41 [95%CI 1.16, 179.11] p = 0.04, but not EIGR, aOR = 0.98 [95%CI 0.90, 1.06], p = 0.58. Neither HIR nor EIGR were not associated with excellent reperfusion, p = 0.38 and p = 0.88, respectively. Patients with higher EIGR were more likely to experience proceduralcomplications, aOR = 1.16 [95%CI 1.03, 1.31], p = 0.01, but there was no difference in HIR, p = 0.28. Lastly, there were no differences in HIR or EIGR and sICH, p = 0.07 and p = 0.68, respectively. Conclusions Very elderly patients aged 90 years or older experienced high rates of mortality and low proportions of good outcomes at 90 days. Nonagenarians with better collaterals as measured by HIR may have better outcomes at 90 days. Additionally, nonagenarians with faster growing ischemic cores may be more likely to experience complications during MST.

Abstract Number ‐ 20: Predictors of Outcomes for Patients with Malignancy and Acute Ischemic Stroke Undergoing Endovascular Therapy

Introduction Patients with active cancer face an increased risk for stroke. Randomized trials studying the efficacy of endovascular therapy for patients with large vessel occlusions generally excluded patients with cancer. Herein, we sought to better understand predictors of outcome for active cancer patients undergoing mechanical thrombectomy for acute ischemic stroke. Methods We conducted a retrospective cohort study of stroke thrombectomy cases performed at our institution from January 2010 to November 2021. Baseline clinical characteristics (age, gender, cancer type, use of anticoagulation, NIHSS, use of tPA, time to reperfusion) were recorded. Study outcomes were successful endovascular reperfusion (≥ TICI 2b) and poor clinical outcome, defined as inpatient death or disposition to hospice. Pearson Chi‐square test and Fisher’s exact test were used to analyze categorical variables, and Mann‐Whitney U tests were used for continuous variables. Multivariable logistic regression analyses were performed to evaluate for independent associations between baseline characteristics and study outcomes. Results Between 2010–2021, we identified 49 patients with active cancer who underwent mechanical thrombectomy for stroke. Their mean age was 63 years (SD, 12), and 43% were men. The leading cancer types were lung (33%) and colorectal (14%). Successful reperfusion was achieved in 78% (95% CI, 66–90%) of patients, and 49% (95% CI, 34–63%) ultimately had a poor clinical outcome. Multivariable analyses yielded no significant predictors for successful reperfusion, while higher NIHSS (1.03, 95% CI, 1.01‐1.06, p = 0.011) and higher cancer stage (1.19, 95% CI, 1.04‐1.34, p = 0.014) were found to be predictors for poor clinical outcome. Conclusions The link between cancer and stroke has become increasingly appreciated. As tPA is often contraindicated in cancer patients with stroke because of recent bleeding or anticoagulant use, thrombectomy may be the only intervention to preserve one’s quality of life. However, we found that despite a high successful reperfusion rate, nearly half of these patients died or were made hospice during the index hospitalization. Future studies should investigate the reasons for poor clinical outcomes in these patients and whether different antithrombotic, blood pressure, or anti‐neoplastic strategies after thrombectomy could improve outcomes.

Are we improving? Temporal trends in outcomes for mechanical thrombectomy for stroke: A systematic review and meta-analysis of randomized trials.

In 2015, mechanical thrombectomy (MT) was deemed the standard of care for acute ischemic stroke (AIS) in the anterior circulation due to large vessel occlusion (LVO). To determine if outcomes in patients treated with MT have changed, we conducted a systematic review and meta-analysis of published randomized controlled trials (RCTs). A systematic literature review of the English language literature was conducted using PubMed. We included RCTs that focused on patients with AIS treated with MT. The primary outcome of interest was good functional outcome defined as modified Rankin Scale (mRS) 0-2 at 90 days. Safety outcomes included rates of symptomatic intracranial hemorrhage (sICH) and mortality at 90 days. Using Joinpoint Regression Analysis Program, we calculated the average annual percent change (AAPC) for the outcomes of interest. We included 23 RCTs with 5784 patients. The years of mid-enrollment among the included RCTs ranged from 2012-2020. There was an AAPC of +3.82% between 2012 and 2020 (95% CI 0.4 to 7.3; P-value = 0.033) in rates of good functional outcome. There was an AAPC of +6.98% between 2012 and 2020 (95% CI 0.5 to 13.9; P-value = 0.039) in rates of sICH. There was an AAPC of -0.49% between 2012 and 2020 (95% CI -4.4 to 3.5; P-value = 0.77) in rates of mortality. Between 2012 and 2020, rates of good functional outcome and sICH increased, while rates of mortality remained consistent in RCTs investigating MT for AIS. Multiple factors likely influenced our results, including increased use of MT and utilization of adjunctive therapies alongside MT.

Defining the optimal size of an aspiration catheter in relation to the arterial diameter during mechanical thrombectomy for stroke

BackgroundMechanical thrombectomy for acute ischemic stroke is effective and includes different technical approaches. Operators use direct aspiration, a stent retriever, or a combination of both. Direct aspiration can be performed with various catheters of different sizes depending on the diameter of the occluded vessel. PurposeWe studied the relationship between the catheter diameter in regards to the occluded vessel diameter and the rate of successful recanalization. Materials and methodsWe conducted a retrospective, monocentric study on a series of consecutive patients treated with mechanical thrombectomy. For each procedure, we extracted each attempt that used direct aspiration and rated the attempt as successful or unsuccessful. We also measured the occluded artery diameter and calculated the ratio between the occluded artery and the aspiration catheter diameters. We tested the association between the diameter ratio and the recanalization status. We also performed inter-rater agreement for the arterial diameter measurement between three interventional neuroradiologists. ResultsWe included 119 patients with 201 attempts of direct aspiration. A higher diameter ratio was associated with a higher recanalization rate. The analysis in terciles showed that the odds of success were 4.80 higher when the ratio was >0.71 vs <0.54 (p < 0.01). Inter-rater agreement showed near-perfect intraclass correlation with 0.93 (0.91–0.94) consistency and 0.92 (0.90–0.94) absolute agreement. ConclusionsWe demonstrated an association between higher recanalization and a diameter of ratio >0.71 between the aspiration catheter and the occluded artery. These results could guide intraoperative decisions regarding the appropriate selection of aspiration catheters during mechanical thrombectomy increasing the rate of successful recanalisation. A larger study could provide additional data to further specify the optimal ratio.

Abstract TP4: Freezing Tenecteplase Aliquots Reduces Waste And Achieves Similar Door To Needle Times And Reperfusion Rates

Objective: To determine the feasibility of using previously frozen tenecteplase (TNK) to treat acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Methods: This is a single-center proof of concept prospective study that was retrospectively analyzed. We began using freshly reconstituted TNK to treat AIS due to LVO in May 2020. In March 2022 we began dividing the 50mg vial of TNK into two frozen 25mg aliquots based on a previously published stability and bioactivity study comparing thawed TNK to freshly reconstituted samples. Our primary outcome was door-to-needle time (DTN) which was analyzed with a quantile regression specifying the median, which was adjusted for age, NIHSS and delays related to treating hypertension. Binomial logistic regression analyses were used to assess secondary outcomes of TNK recanalization rate prior to mechanical stroke thrombectomy (MST) and excellent reperfusion scores (≥TICI 2C) after MST in the fresh and previously frozen TNK groups. Results: Five frozen TNK vials (ten aliquots) had been created since implementation of freezing TNK. Seven previously frozen aliquots were thawed and used, while three aliquots expired and were discarded. We analyzed the seven previously frozen TNK aliquots against the sixty eight freshly reconstituted TNK vials used to treat acute ischemic stroke patients. Median DTN was similar between previously frozen, 41 (IQR, 27 - 53) and fresh TNK, 46 (IQR, 37 - 60), p = 0.12. There was no difference in the LVO recanalization rate prior to MST in previously frozen, 0 (0.0%) and fresh TNK, 2 (2.9%), p = 0.99. Patients undergoing MST achieved similar rates of excellent reperfusion in previously frozen, 4 (66.7%) and fresh, 30 (56.6%) TNK treated patients, Odds Ratio = 1.55 [95%CI, 0.25, 9.70], p = 0.64 Conclusions: It is feasible to freeze 50mg vials of TNK into two 25mg aliquots to use to treat acute ischemic stroke. We found similar DTN times, indicating that thawing the previously frozen TNK did not delay IV thrombolysis administration. Additionally, we found similar reperfusion rates prior to and after MST with freshly reconstituted and previously frozen TNK.

Abstract TMP67: Automated Measurement Of Vascular Tortuosity: Association With Baseline Clinical Characteristics And Impact On Thrombectomy Procedures

Introduction: Vascular tortuosity is considered one of the main barriers for mechanical thrombectomy in stroke. We developed a fully automatic algorithm for vascular tortuosity characterization and explored the association of several anatomical features with baseline characteristics and procedural outcomes. Methods: An automatic software integrating segmentation, centerline extraction and vessel labelling, was used to extract features directly from computed tomography angiograms (CTA) of stroke patients undergoing transfemoral endovascular treatment. Mean diameter and tortuosity index (TI) of the carotid arteries and brachiocephalic trunk were used as relevant tortuosity indicators. Patients were compared according to seven different clinical conditions and four procedural measures. Results: 518 patients (51% female, 74.8±12.9 years) were included in this study. Women presented significantly smaller vessels and increased TI in both carotid arteries ( p &lt;.01). Hypertension and atrial fibrillation were associated with higher TI in both carotid arteries ( p &lt;.01). Age correlated with TI in all vessels (.35&lt; r&lt; .52, p &lt;.01). Patients with longer time to first angiographic run and time to revascularization presented higher TI in all ipsilateral carotid segments ( p &lt;.05). Conclusion: An automated software was successfully used to characterize anatomical vascular features from CTA. Gender, age, hypertension and atrial fibrillation were found to influence vascular tortuosity. The algorithm was able to detect higher TI in ipsilateral carotid arteries of patients with further difficult catheter access or longer time to revascularization. This information could potentially be used to plan best arterial access site.

Abstract TP145: Mechanical Thrombectomy Beyond 24 Hours

Background: Multiple randomized controlled trials have shown that mechanical thrombectomy (MT) is superior to medical therapy. However, no robust evidence is available to assess the effectiveness of MT beyond the 24-hour window. In this study, we aimed to determine the safety and efficacy of MT in patients undergoing MT for stroke beyond 24 hours from last known normal (LKN). Methods: Retrospective review of a prospectively collected database for subjects who met extended window trial criteria, but underwent MT beyond 24 hours. Recorded variables included age, sex, NIHSS at baseline and at discharge, risk factors, level of occlusion, access site, thrombectomy method. Safety and efficacy outcomes included symptomatic intracerebral hemorrhage (sICH), procedural complications, number of passes, successful recanalization (TICI 2b-3), Δ NIHSS (baseline-discharge), favorable outcomes (mRS 0-2) at 90 days. Results: A total of 39 patients were included with a median age of 69 (IQR 61.5, 73.5); 54% were females. Hypertension was the most frequent risk factor in 76% of patients; 23 % of patients were smokers. Half of the patients had M1 occlusion (48.7%). Median preprocedural NIHSS was 11 (IQR 7.0, 19.5). Successful revascularization was achieved in 87%; median number of passes was 2 (IQR 1.0,3.0). Median ΔNIHSS was 3.0 (IQR -1.5, 8.0). Favorable outcome was achieved in 49% (95% CI: 34%-64%), and 95% were free of complications. A total of 3 patients (7.7%) had sICH. In an exploratory analysis, posterior circulation occlusion was associated with higher risk of poor mRS at 90 days (OR: 14.7, p = 0.016). Additionally, favorable discharge facility (home, home health, or rehab) was associated with a much lower risk of poor mRS at 90 days (OR: 0.11, p = 0.004). Conclusions: Our single center study of MT beyond 24 hours showed comparable clinical outcomes and safety profile to large MT trials within 24 hours, especially in anterior circulation occlusions. Posterior circulation occlusions were associated with worse outcomes, which warrants further investigation.

Abstract 28: First Pass Outcomes And Associated Clot Characteristics: Secondary Analysis Of The Excellent Registry

Introduction: EXCELLENT (NCT03685578) is a global prospective, multicenter, real-world registry of mechanical thrombectomy for stroke with the EmboTrap device as first line treatment which includes clot collection and analysis. Aim of the study: To report the rates of clinical outcomes and clot characteristics associated with first pass reperfusion in EXCELLENT. Methods: Per pass angiographic outcomes assessed by an independent core lab were available in 984 subjects Analysis of clot from 538 cases was performed by independent central labs blinded to clinical data. 90-day mRS assessment was blinded to subject data. Results: First pass reperfusion of mTICI 2b-3 (63.2%) and 2c-3 (38.3%) was significantly predictive of mRS 0-2 or ≤pre-stroke (p=0.011 and p=0.016) but not all-cause mortality at 90 days (p=0.080 and p=0.123, respectively). Further, mTICI 2c-3 in one pass was associated with a higher rate of mRS 0-2 or ≤pre-stroke vs. mTICI 2c-3 reperfusion in &gt;1 pass, (55.5% and 45.1%, respectively, p=0.013) and a rate of all-cause mortality at 90 days of 14.6% vs. 19.8% (p=0.097). Full patient characteristics and clinical outcomes are shown in Table 1. Notable clot composition findings included: RBC (%, mean±SD): mTICI 2c-3, 1 pass 47.69±22.25, mTICI 2c-3, &gt;1 pass 43.86±19.05, (p=0.088); fibrin: mTICI 2c-3, 1 pass 23.20±13.80, mTICI 2c-3 &gt;1 pass 25.40 ± 13.52 (p=0.131); von Willebrand factor (VWF): mTICI2c-3, 1 pass 16.09±14.62, mTICI 2c-3, &gt;1 pass 19.42±17.15 (p=0.038). Conclusions: First pass reperfusion in the EXCELLENT registry was associated with better clinical outcomes at 90 days. Clots retrieved with first pass reperfusion had higher RBC and lower fibrin and VWF content compared to those who achieved reperfusion at greater than one pass.

A comparison of low- versus standard-dose bridging alteplase in acute ischemic stroke mechanical thrombectomy using indirect methods.

Whether low-dose alteplase is similar to standard-dose bridging alteplase prior to endovascular mechanical thrombectomy in patients with acute ischemic stroke (AIS) remains uncertain. The aim of this study was to compare the efficacy and safety outcomes of low- versus standard-dose bridging alteplase therapy (BT) in patients with acute ischemic stroke (AIS) who are eligible for intravenous thrombolysis (IVT) within 4.5 h after onset. We conducted an indirect comparison of low- versus standard-dose bridging alteplase before mechanical thrombectomy in AIS of current available clinical randomized controlled trials (RCTs) that compared direct mechanical thrombectomy treatment (dMT) to BT. Primary efficacy outcomes were functional independence and excellent recovery defined as a dichotomized modified Rankin Scale (mRS) 0-2 and 0-1 at 90 days. Safety outcomes included symptomatic intracranial hemorrhage (sICH) and any intracranial hemorrhage (ICH). We included six RCTs of 2334 AIS patients in this analysis, including one trial using low-dose bridging alteplase (n = 103) and five trials using standard-dose bridging alteplase (n = 1067) against a common comparator (dMT). Indirect comparisons of low- to standard-dose bridging alteplase yielded an odds ratio (OR) of 0.84 (95% CI 0.47-1.50) for 90-day mRS 0-2, 1.18 (95% CI 0.65-2.12) for 90-day mRS 0-1, 1.21 (95% CI 0.44-3.36) for mortality, and 1.11 (95% CI 0.39-3.14) for successful recanalization. There were no significant differences in the odds for sICH (OR 1.05, 95% CI 0.32-3.41) or any ICH (OR 1.71, 95% CI 0.94-3.10) between low- and standard-dose bridging alteplase. Indirect evidence shows that the effects of low- and standard-dose bridging alteplase are similar for key efficacy and safety outcomes. Due to the wide confidence intervals, larger randomized trials comparing low- and standard-dose alteplase bridging therapy are required.

Mechanical Thrombectomy for Stroke Due to Acute Basilar Artery Occlusion, a Safety and Efficacy Analysis.

Acute basilar artery occlusion accounts for 1% of all ischemic strokes but often leads to devastating neurological injury and mortality. Many institutions still opt for best medical therapy for these patients; however, there is increasing evidence that mechanical thrombectomy (MT) for these patients leads to better outcomes. To assess the safety and efficacy of MT for patients presenting with acute basilar artery occlusion (BAO). This study was a retrospective chart review of a prospectively maintained database for patients with acute BAO treated with MT from January 2014 through March 2022. Our study included a total of 74 patients. The mean age was 62.7 years, and 55.4% were male. The most common comorbidity was hypertension (73%). The mean door to puncture time was 75 minutes, and the mean procedure time was 54 minutes. 86.5% of patients had a good modified treatment in cerebral ischemia score (≥2b). There were 4 patients who had procedural complications and 3 who had symptomatic intracerebral hemorrhage. At 90 days, 62.5% of patients had a modified Rankin Scale, 0 to 3. The mortality rate was 32.4% and 2% during hospital admission and 90 days, respectively. On univariate analysis, adjunctive angioplasty/stenting and higher presenting National Institutes of Health Stroke Scale score were associated with modified Rankin Scale 4 to 6 at 90 days ( P -value, .03 and <.001, respectively). Shorter procedure time was associated with modified treatment in cerebral ischemia score ≥ 2b ( P -value, .0015). Our findings showed that MT is safe and effective for patients presenting with acute BAO and is in conjunction with previous literature. The results from upcoming trials should hopefully establish MT as gold standard for these patients.

Internal carotid artery patency after mechanical thrombectomy for stroke due to occlusive dissection: Impact on outcome.

Internal carotid artery dissection (ICAD) is a rare cause of acute ischemic stroke with large vessel occlusion (AIS-LVO). We aimed investigating the impact on outcome of internal carotid artery (ICA) patency after mechanical thrombectomy (MT) for AIS-LVO due to occlusive ICAD. We included consecutive patients with AIS-LVO due to occlusive ICAD treated with MT from January 2015 to December 2020 in three European stroke centers. We excluded patients with unsuccessful intracranial reperfusion after MT (modified Thrombolysis in Cerebral Infarction (mTICI) score < 2b). We compared 3-month favorable clinical outcome rate, defined as a modified Rankin scale (mRS) score ⩽2, according to ICA status (patency vs occlusion) at the end of MT and at 24-h follow-up imaging, using univariate and multivariable models. Among 70 included patients, ICA was patent in 54/70 (77%) at the end of MT, and in 36/66 (54.5%) patients with 24-h follow-up imaging. Among patients with ICA patency at the end of MT, 32% presented ICA occlusion at 24-h control imaging. Favorable 3-month outcome occurred in 41/54 (76%) patients with ICA patency post-MT and in 9/16 (56%) patients with occluded ICA post-MT (p = 0.21). Rates of favorable outcome were significantly higher in patients with 24-h ICA patency compared to patients with 24-h ICA occlusion (32/36 [89%] vs 15/30 [50%]), with an adjusted odds ratio of 4.67 (95% CI: 1.26-17.25). Obtaining sustained (24-h) ICA patency after MT could be a therapeutic target for improving functional outcome in patients with AIS-LVO due to ICAD.

Access to Mechanical Thrombectomy for Stroke: Center Qualifications, Prehospital Management, and Geographic Disparities.

Mechanical thrombectomy (MT) became the "gold-standard" treatment for most patients with acute ischemic stroke due to anterior circulation large vessel occlusion. With such a remarkable paradigm shift, it is important that this modality of treatment becomes widely and homogeneously available throughout the United States and other countries. Although the time window for MT is large (24 hours in selected patients), time is still a major determinant of outcome. Several variables are involved in achieving timely access of MT for the majority of the population: prehospital management systems, transportation models, in-hospital workflow organization, accreditation and infrastructure of centers, training of neurointervention professionals, and geographic distribution of centers. The current situation in the United States regarding MT access is marked by geographic and socioeconomic disparities. We provide an overview of current challenges and solutions in achieving more universal access to MT for the population.