Treatment Of Large Vessel Occlusion Research Articles

Rescue stenting in refractory mechanical thrombectomy: A review

Despite advancements in mechanical thrombectomy (MT) in the treatment of large vessel occlusions, failure to achieve recanalization remains a challenge in 10 – 30% of patients. Several underlying pathologies have been postulated in refractory MT, including intracranial atherosclerotic stenosis, intracranial dissection, and recalcitrant emboli. Rescue strategies to maximize recanalization rates, such as alternative access routes, local thrombolysis, stent-assisted angioplasty, and acute “rescue” stenting, have been proposed. Considered an emerging treatment strategy for refractory MT, rescue stenting (RS) has been shown in non-randomized observational studies as a safe and effective strategy for increasing reperfusion rates and consequently improving clinical outcomes. The effective use of RS approach requires consideration of patient-specific characteristics, clot characteristics, and lesion anatomy. This review provides an overview of the understanding of refractory MT, epidemiology, pathophysiology, current evidence supporting RS in the anterior and posterior circulation, stents used, endovascular techniques, patient selection criteria, antithrombotic use, risks, and complications.

A prospective, randomized, controlled, interventional clinical trial to evaluate the safety and efficacy of the medical monopoint reperfusion system for aspiration thrombectomy in acute ischemic stroke patients (SUMMIT MAX): Trial rationale and design.

Treatment of large vessel occlusion (LVO) using mechanical thrombectomy with or without intravenous thrombolysis has demonstrated better outcomes compared to medical treatment alone. Large-bore aspiration catheters have been recently introduced. Their effectiveness and safety have not been demonstrated in a randomized trial. The SUMMIT MAX study is designed to address this question. SUMMIT MAX is a randomized controlled trial where the effectiveness and safety of the large-bore Monopoint Reperfusion system (Route 92 Medical, San Mateo, CA), will be compared to the currently largest available FDA-cleared aspiration thrombectomy device the AXS Vecta Aspiration system (Stryker Neurovascular, Fremont, CA). The study is a multi-center, prospective, randomized, controlled, interventional, open label clinical trial. The hypothesis is that the effectiveness measured by the recanalization rate (modified thrombolysis in cerebrovascular infarction - mTICI) and safety measured by symptomatic intracranial hemorrhage rate (sICH) of the medical monopoint reperfusion system is non-inferior to the AXS Vecta Aspiration system. Up to 250 subjects are enrolled with at least 50% of subjects enrolled by US sites. The primary effectiveness endpoint is successful arterial revascularization defined as an mTICI score ≥ 2b after use of the assigned device adjudicated by an independent core lab. The primary safety endpoint is defined as sICH within 24 h (-8/+24) post-procedure. Secondary endpoints include successful arterial revascularization defined as a mTICI score ≥ 2b after use of the assigned device with or without adjunctive therapy; device-related serious adverse events; all asymptomatic hemorrhages; time from groin puncture to final angiogram; and rate of first pass effect defined as mTICI 2b after first pass with the assigned device stratified by age (≤85, ≥ 86). SUMMIT MAX is a randomized controlled trial comparing the effectiveness and safety of a new large bore class of aspiration devices to the currently largest FDA-cleared aspiration device available.

HERMES-24 Score Derivation and Validation for Simple and Robust Outcome Prediction After Large Vessel Occlusion Treatment.

Clinicians need simple and highly predictive prognostic scores to assist practical decision-making. We aimed to develop a simple outcome prediction score applied 24 hours after anterior circulation acute ischemic stroke treatment with endovascular thrombectomy and validate it in patients treated both with and without endovascular thrombectomy. Using the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) collaboration data set (n=1764), patients in the endovascular thrombectomy arm were divided randomly into a derivation cohort (n=430) and a validation cohort (n=441). From a set of candidate predictors, logistic regression modeling using forward variable selection was used to select a model that was both parsimonious and highly predictive for modified Rankin Scale (mRS) ≤2 at 90 days. The score was validated in validation cohort, control arm (n=893), and external validation cohorts from the ESCAPE-NA1 (Efficacy and Safety of Nerinetide for the Treatment of Acute Ischaemic Stroke; n=1066) and INTERRSeCT (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography; n=614). In the derivation cohort, we selected 2 significant predictors of mRS ≤2 (National Institutes of Health Stroke Scale score at 24 hours and age [β-coefficient, 0.34 and 0.06]) and derived the HERMES-24 score: age (years)/10+National Institutes of Health Stroke Scale score at 24 hours. The HERMES-24 score was highly predictive for mRS ≤2 (c-statistic 0.907 [95% CI, 0.879-0.935]) in the derivation cohort. In the validation cohort and the control arm, the HERMES-24 score predicts mRS ≤2 (c-statistic, 0.914 [95% CI, 0.886-0.944] and 0.909 [95% CI, 0.887-0.930]). Observed provability of mRS ≤2 ranged between 3.1% and 3.4% when HERMES-24 score ≥25, while it ranged between 90.6% and 93.0% when HERMES-24 score <10 in the derivation cohort, validation cohort, and control arm. The HERMES-24 score also showed c-statistics of 0.894 and 0.889 for mRS ≤2 in the ESCAPE-NA1 and INTERRSeCT populations. The post-treatment HERMES-24 score is a simple validated score that predicts a 3-month outcome after anterior circulation large vessel occlusion stroke regardless of intervention, which helps prognostic discussion with families on day 2.

1249 Single-Center Outcomes of Onyx Frontier and Resolute Onyx Drug-Eluting Balloon Mounted Stents for Rescue Stenting for Acute Large Vessel Occlusion

INTRODUCTION: Mechanical thrombectomy (MT) is a common treatment for large vessel occlusions with recent literature expanding its indications. In cases where MT fails, rescue stenting may be necessary to achieve reperfusion; however, the absence of standardized techniques or devices poses a challenge. METHODS: A retrospective chart review was performed of all patients who underwent rescue stenting, in the setting of MT, using Onyx Frontier or Resolute Onyx stents at a single institution. Technical details, procedural complications, and patient outcomes were recorded for each case. RESULTS: In total, 21 Onyx Frontier and Resolute Onyx stents were deployed in 18 patients undergoing rescue stenting. Among these, 13 involved the use of Resolute Onyx stents, while 5 cases utilized Onyx Frontier stents. Stent locations included the middle cerebral artery (40%), internal carotid artery (15%), vertebral artery (20%), and basilar artery (25%). The average NIHSS score before MT was 13.83 (range 0-31). The median initial mRS score was 0, while the median mRS score at follow-up was 3. Successful reperfusion, as assessed by TICI scores, was achieved in 43.8% of patients for TICI 3, 43.8% for TICI 2C, and 12.5% for TICI 2B. The average proximal vessel diameter was 2.31 mm, and the most used stent length was 12 mm. Post-revascularization, 33% of patients experienced hemorrhage, of which only one patient (16.7%) had symptomatic hemorrhage due to vessel rupture necessitating hemicraniectomy. CONCLUSIONS: Onyx Frontier and Resolute Onyx stents are well-suited for rescue stenting in cases where aspiration and stentriever techniques fail during MT. These balloon-mounted drug-eluting stents exhibit excellent navigability, rendering them appropriate for rescue revascularization procedures. Our findings demonstrate that these stents confer a high degree of technical success and a low rate of intra- and post-procedural complications.

Mechanical thrombectomy for the treatment of large vessel occlusion due to cancer-related cerebral embolism: A systematic review

Background Cancer-related cerebral embolism due to direct tumor embolization results in a rare acute ischemic stroke with large vessel occlusion (LVO). Despite the established status of mechanical thrombectomy (MT) in LVO management, its effectiveness and safety remains inadequately explored in this specific patient group. Methods We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using the Nested Knowledge AutoLit software, encompassing databases like Embase, PubMed, Scopus, and Web of Science, from their inception up to 9 May 2023. Results In the review of 35 studies encompassing 37 cases, mean patient age was 52 years, and 30% were female. Cardiac myxoma (29.7%), cardiac papillary fibroelastoma (16.2%), and squamous cell carcinoma of the lung (8.1%) were the most frequent underlying cancers. The left middle cerebral artery was the most commonly affected occlusion site (24.3%). Of the patients, 67.5% underwent MT alone, while 32.5% received MT combined with intravenous thrombolysis. Successful reperfusion (thrombolysis in cerebral infarction (TICI) 2b–3) was achieved in 89.1% of cases, with 59.4% reaching TICI 3. Functional independence was observed in 29.7% of patients. Conclusion While limitations exist, this comprehensive study highlights the potential benefits of MT in a patient group historically excluded from major trials, warranting further investigation.

Abstract TP191: National Trends in Rescue Therapy for Failed Thrombectomy 2009-2020

Introduction: For a subset of patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO) mechanical thrombectomy with a stent retriever and/or aspiration is insufficient to revascularize the target artery. Rescue therapy with angioplasty alone or with stenting has been utilized. This study assesses the longitudinal trends for adjunctive treatments following failed thrombectomy in the U.S. Methods: We performed a data search from the National Inpatient Sample (NIS) database using ICD9 and ICD10 procedure codes from 2009 through 2020. Data was collected for patients with stroke who underwent thrombectomy for LVO and subsequent angioplasty or angioplasty and stenting. The use of drug eluting stents, patient demographics, regional trends, length of stay, and mortality statistics were also assessed. Results: Between 2009 and 2020, the NIS data shows a significant increase in the use of stenting as adjunctive therapy to thrombectomy for LVO. In 2009, stenting with thrombectomy in LVO represented 5.6% (25/443) of patients stented with stroke from ICAD. In 2020, these cases represented 48.6% (520/1,070) of the patients stented. Over the study period, this increase in stent use during LVO treatment was significant (p&lt;0.001). There has been a mild increase in the use of drug eluting stents in rescue therapy, but not as significant as bare metal stents. Angioplasty as an adjunct to thrombectomy for LVO has steadily increased over the study period, with 87 cases in 2009 and 265 cases in 2020, representing a 205% increase. Conclusion: There has been a progressive, significant increase in the number of rescue procedures for failed thrombectomy over the study period with stent procedures outnumbering angioplasty alone. Referencing published data these cases represent approximately 2-3% of the total number of thrombectomies performed for AIS.

Usefulness of Mechanical Thrombectomy in Patients with Cancer Who Developed Cerebral Infarction.

Mechanical thrombectomy (MT) is an established treatment for large vessel occlusion in the acute phase of stroke. However, its efficacy and safety in patients with cancer remain unclear. This study aimed to evaluate the therapeutic effect of MT against large vessel occlusion between patients with and without cancer. A total of 71 patients who underwent MT from August 2014 to November 2021 were included in this study. Patients with cancer and/or a history of cancer (n = 16) were included in the with cancer group and the remaining patients in the without cancer group (n = 55). The frequency of preoperative tissue plasminogen activator administration was significantly lower in the with cancer group (n = 2 [12.5%]) than in the without cancer group (n = 24 [43.6%]). However, there were no significant differences between the two groups in terms of treatment time, pass frequency, thrombolysis in cerebral infarction grade, modified Rankin scale score at 1 week after treatment [mRS (1w) ], modified Rankin scale score at discharge [mRS (ENT) ], modified Rankin scale score at 90 days after treatment [mRS (90 days) ], and length of hospital stay (days). In the multivariate analysis, if the objective variables were mRS (1w) and mRS (90 days), the National Institutes of Health Stroke Scale (NIHSS) and preonset mRS scores were considered significant variables. The presence or absence of cancer was not considered an independent factor of mRS (1w), mRS (ENT), or mRS (90 days). Aggressive treatment may be recommended to patients with cancer and/or a history of cancer who present with a systemic condition that can be managed with MT.

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 246: Effect of platelet count on outcome in ischemic stroke patients with LVO undergoing MT;a meta‐analysis

Introduction Large randomized clinical trials have established the superiority of Mechanical Thrombectomy (MT) for the treatment of Large Vessel occlusion (LVO) in patients with Acute Ischemic stroke (AIS) in terms of revascularization rates and clinical outcomes as compared to IV‐tPA alone.(1, 2, 3) However, Data regarding outcomes of mechanical thrombectomy in patients with low platelets is limited and shows conflicting results. (4, 5, 6, 7, 8) Methods This meta‐analysis was performed according to the preferred reporting items for systematic review and meta‐analysis (PRISMA) guidelines.(9) We defined thrombocytopenia as platelet count &lt; 150,000 /μL. We further classified these patients into two groups: 1) Mild thrombocytopenia (Platelet count 100,000 – 149,000 /μL) and 2) Moderate to severe thrombocytopenia (Platelet count &lt;100,000 /μL). The favourable outcome was 90‐day functional independence, designated as an Modified Rankin Score (MRS) ≤ 2 at 90 days. Unfavorable outcomes were 1) Symptomatic Intracranial hemorrhage (sICH) and 2) Mortality at 90 days. Results All studies were determined to be of good/high quality (Newcastle Ottawa scale).(10) Compared to patients with normal platelets, Patients with low platelets (&lt; 150,000 /μL) had a statistically significant worse outcome (mRS &gt;2 )at 90 days (RR 0.80 [95% CI: 0.69 ‐ 0.94] p = 0.006). However, on analysis based on different platelet cutoff values, the difference in mRS score was not statistically significant in patients with Mild low platelets (100,000 – 149,000 /μL) (RR 0.84 [95% CI: 0.70 ‐ 1.00] p = 0.05) and moderate/severely low platelets (&lt; 100,000 /μL) (RR 0.71 [95% CI: 0.48 ‐ 1.06] p = 0.09) when compared to patients with normal platelets. Similarly, Mortality was significantly increased in patients in the low platelet group (RR 1.95 [95% CI: 1.62 ‐ 2.36] p &lt; 0.00001). Mortality was also significantly increased in the mild low platelet subgroup (RR 1.88 [ 95% CI: 1.34 ‐ 2.63] p = 0.0002) and moderate/severe low platelet subgroup (RR 2.07 [95% CI: 1.46 ‐ 2.92] p &lt; 0.0001) when compared to patients with normal platelets. Furthermore, sICH events were significantly increased in patients in the low platelet group (RR 2.47 [95% CI: 1.51 ‐ 4.05] p = 0.0003). Similarly, on analysis based on different platelet cutoff values, sICH was also significantly increased in the mild low platelet subgroup (RR 2.34 [ 95% CI: 1.24 ‐ 4.40] p = 0.008) and moderate/severe low platelet subgroup (RR 4.13 [95% CI: 2.00 ‐ 8.50] p = 0.0001). Conclusion Our meta‐analysis revealed that compared to individuals with normal platelet count, those with platelet count (&lt; 150,000 /μL) had worse functional outcomes (MRS ≤ 2) , higher mortality rates, and a greater incidence of sICH. However, on analysis based on different platelet cutoffs, difference in MRS score was insignificant while the mortality rates and sICH incidence remained significantly higher. This may be attributed to smaller number of studies in the “cut‐off” groups leading to decreased power. Nevertheless, our findings suggest that MT for LVO in patients with low platelets leads to worse outcomes, however these risk were not significant in group with mild thrombocytopenia. Hence, Clinicians should carefully monitor for these risks while performing procedure or post procedure care.

Abstract 214: Predictors of Mechanical Thrombectomy Success and Failure: A Preliminary Analysis

Introduction Mechanical thrombectomy (MT) is now the standard of care in treatment of large vessel occlusion (LVO) in acute ischemic stroke (AIS). However, a significant minority of patients do not achieve successful recanalization. Previous case series’ have reported failed recanalization at a rate of approximately 12% (1). In the present study, we investigated clinical and procedural characteristics predictive of MT success and failure. Methods We conducted a retrospective analysis of MT patients with LVO presenting to our academic comprehensive stroke center from 2015‐2020. Recanalization failure was defined as TICI 0‐2a and success as TICI 2b‐3. We compared all 49 consecutive failure cases to a random selection of 85 successful MT cases. Demographic, clinical, procedural, and outcome data were compared between the two groups. Results In this cohort, there was no statistically significant difference in sex, pre‐stroke modified Rankin score (mRS), admission National Institutes of Health Stroke Scale (NIHSS), door‐to‐groin time, thrombolytic use, or site of occlusion between the two groups. In the success group, patients were older (76 vs 61, p=0.003), and had a higher average number of atherosclerotic risk factors (p=0.002). There was a higher proportion of embolic stroke of undetermined source (ESUS) in the success group compared with the failure group (8.5% vs 0%, p=0.039). A higher proportion of failure cases were due to large artery atherosclerosis (30.6% vs 19.5%, p=0.12) and cardioembolism (55.1% vs 67.1%, p=0.27), though neither of these differences were statistically significant. Stent‐retrieval alone (SR) was a more common first pass technique in failed than in successful MT (14.3% vs 0%, p=0.001). Conclusion This study investigated clinical and procedural factors associated with successful and failed recanalization in MT. In this cohort, stent‐retrieval alone as a first pass technique was more commonly associated with failed MT. Stroke etiology was associated with rates of failure, with a significantly higher proportion of ESUS in successful cases and a trend toward a higher proportion of large vessel atherosclerosis and cardioembolism in failed MT.

Primary Endovascular Thrombectomy in Acute Ischemic Stroke in Patients Ineligible for Intravenous Thrombolysis

Endovascular treatment (EVT) of acute ischemic stroke (AIS) is the main treatment of large vessel occlusion (LVO). Nonetheless, access to EVT is limited specially in developing countries. It is not uncommon in these regions to miss the time window for intravenous thrombolysis (IVT) or to arrive within the IVT window but with a contraindication for it. Hence, a lot of patients with LVO face a situation where either they receive EVT only or conservative management according to available logistics.&#x0D; Aim: To study the outcome of EVT vs best medical treatment (BMT) in two Egyptian stroke centres (Tanta and Alexandria) in AIS patients ineligible for IVT.&#x0D; Results: 390 patients with AIS and LVO were included in the study. 74 underwent EVT while 316 underwent BMT. There were no statistical differences in age, sex, time of onset, initial severity, or imaging scores in both groups. The EVT group had more diabetes mellitus (DM) patients, more smokers and more systolic and diastolic blood pressure (BP) while the BMT had more anticoagulated patients. The EVT group had better functional outcome but more symptomatic intracerebral haemorrhage with no difference in mortality.&#x0D; Conclusion: Endovascular treatment doubles the good functional outcome of AIS in LVO patients but ICH is more with no effect on mortality.

Toward Faster Revascularization in Large Vessel Acute Ischemic Stroke: Reducing Door-to-Groin Puncture Times

Stroke treatment has evolved immensely over the past 3 decades, with mechanical thrombectomy becoming the mainstay of treatment for large vessel occlusion (LVO). In this review, we describe the progression from PROACT I to the present day, and analyze existing literature to summarize the efficacy of current methods to treat LVO. We also describe the indications for mechanical thrombectomy and the strategies that have been implemented to enhance its efficacy, including a quality improvement project conducted at the Mayo Clinic. In addition, we discuss lessons from the implementation of mechanical thrombectomy and advancements in this technique over recent years.

Thyroid hormone decreasing after mechanical thrombectomy for cerebral infarction (P3-5.018)

<h3>Objective:</h3> The aim of this study wasto clarify the changes in thyroid hormone levels in the acute phase and the effects of the iodine contrast agent on thesehormones. <h3>Background:</h3> Mechanical thrombectomy (MT) is an established treatment for large vessel occlusion in patients with cerebral infarction. The use of iodine contrast agent decreases thyroid hormone levels via the so-called Wolff-Chaikoff effect. Low triiodothyronine (T3) syndrome caused by a severe illness status can contribute to decreased thyroid hormones. Reportedly, a low T3 level is associated with poor prognosis in patients with cerebral infarction. <h3>Design/Methods:</h3> This was a single-center, prospective, and single-arm trial. Thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were tested on admission and 24 h postoperatively in patients who were approved for MT. <h3>Results:</h3> A total of 37 patients were screened during the study period and 31 patients were enrolled. Significant decreases were observed in TSH (<i>P</i> &lt; 0.001) and FT3 (<i>P</i> &lt; 0.001) levels 24 h after MT. Moreover, there was a correlation between the decrease ratio of change in FT3 levels and the amount of iodine contrast agent used per body surface area (<i>r</i> = 0.43, <i>P</i> = 0.019), while no such correlations were detected for TSH and FT4. <h3>Conclusions:</h3> We demonstrated that decrease in TSH and FT3 levels in the acute phase after MT and that FT3 levels were associated with the amount of iodine contrast agent used. <b>Disclosure:</b> Dr. Kobayashi has nothing to disclose.

476 Technical and Clinical Outcomes in Concurrent Multivessel Occlusions Treated With Mechanical Thrombectomy: Insights from the STAR Collaboration

INTRODUCTION: Endovascular thrombectomy(EVT) has become the mainstay treatment of large vessel occlusion, however its role in the treatment of patients with simultaneous multi-territory occlusions(MVOs) has not been established. METHODS: We reviewed the STAR registry and included patient data from 35 stroke centers for EVT performed to treat bilateral anterior or concurrent anterior and posterior circulation occlusions from 2017-2020. RESULTS: We included a total of 7723 patients who underwent EVT for acute ischemic stroke. 54 patients (0.7%) underwent EVT for MVOs (mean age 69 ± 12.5; Female 50%). 28% had bilateral and 72% had concurrent anterior and posterior circulations occlusions. We used propensity score matching to match patients with MVOs to another group with single vessels occlusions by age, gender, race, admission NIHSS, baseline mRS score, onset to groin, use of IV-tPA. The rate of recanalization (TICI2B/3), complications, modified Rankin score at 90 days, and mortality was not significantly different between the 2 groups. Multivariate analysis confirmed that MVOs was not a predictor of poor functional outcome, increased symptomatic hemorrhage, or longer procedure time. CONCLUSIONS: Compared to single vessel occlusions, EVT in appropriately selected MVOs has similar efficacy and safety profile.

556 A Matched-Pair Analysis of Patients with Ischemic Strokes Undergoing Thrombectomy Using the BOBBY Balloon Guide Catheter

INTRODUCTION: Endovascular thrombectomy has become the standard-of-care in treatment of large-vessel occlusion. Despite evidence of enhanced clot retrieval with balloon guide catheters (BGC), their routine use is yet to be widely adopted possibly due to incompatibility of past generation BGCs with large bore intermediate catheters. The next-generation BOBBY BGC is compatible with the 0.070-inch SOFIATM Flow Plus catheter. METHODS: We conducted a retrospective study of 112 thrombectomy cases utilizing BGC (N = 56) and non-BGC (N=56) methods. Sixty consecutive thrombectomy cases that used BOBBYTM BGC (MicroVention, Aliso Viejo, CA) at a single institution between 2/2021-3/2022 were identified. Of them, 56 BGC cases were 1:1 matched with non-BGC cases performed between 4/2016-12/2021 by proceduralists, age (±10 years), gender, stent retriever + aspiration device versus aspiration-only, and site of occlusion. First-pass effect was defined as Thrombolysis In Cerebral Infarction scale ≥IIB with a single pass, and good functional outcome as Modified Rankin Scale ≤2. RESULTS: BGC and non-BGC cohorts had similar mean age (67 versus 69 years), gender distribution (44.6%, 48.2% females), mean initial National Institutes of Health Stroke Scale (14.5, 14), and median pre-treatment ischemic core volumes (12.5 ml, 11 ml). BGC and non-BGC cases had similar rates of single pass (58.9%, 55.4%), first-pass effect (57.1%, 50.0%), and complications (5.4%, 8.9%). In aspiration-only cases, adding BGC led to a significantly higher rate of first-pass effect (71.4% vs 50.0%, P = 0.01). BGC was associated with higher likelihood of achieving good functional outcome at discharge (OR 2.30, P = 0.01). No additional procedural time was required for BGC cases (46.7 versus 48.4 minutes). CONCLUSIONS: An initial one-year experience from a tertiary academic center shows BGC can be safely adopted with comparable procedural efficacy, benefits to aspiration-only techniques, and earlier functional improvement when compared to conventional guide catheter cases.

Number Needing Review: A Novel Metric to Assess Triage Efficiency of Large Vessel Occlusion Detection Systems

Background Endovascular thrombectomy is the gold‐standard treatment for large vessel occlusions (LVOs). A novel metric is introduced: the number needing review (NNR) to assess the triage efficiency of LVO detection systems. Methods Patients with suspected ischemic stroke and images processed by RapidAI LVO detection software over 6 months were reviewed. Only patients with LVOs of the M1 segment were included. The NNR was calculated for an M1 occlusion. Results Of 559 patients, M1 occlusion was detected in 42 patients (7.5%). RapidAI LVO had a sensitivity of 71%, specificity of 94%, positive predictive value of 49%, and negative predictive value of 92% for M1 occlusion. When gaze deviation and hyperdense sign were combined with RapidAI LVO, the specificity and positive predictive value increased to 100% for an M1 occlusion. A negative RapidAI LVO result combined with a low (&lt;15 mL, T max &gt;6 seconds) or high (&lt;50 mL, T max &gt;6 seconds) T max threshold was found to have a specificity and positive predictive value of 100% for no occlusion. The combination of gaze deviation, hyperdense sign, positive RapidAI LVO, and negative RapidAI LVO with low T max threshold yielded an NNR of 24 per 100 cases. When combined with a negative RapidAI LVO and a high T max threshold, the NNR was 16 per 100 cases. Adding National Institutes of Health Stroke Scale score &lt;7 decreased the NNR to 9 per 100 cases. Conclusion Adding gaze deviation and hyperdense sign to the RapidAI LVO increases the specificity and positive predictive value for an M1 occlusion. When combined with a negative RapidAI LVO detection and either a low or high T max &gt;6 seconds threshold, the NNR is significantly reduced.

A Retained Microcatheter Fragment in the middle cerebral artery: report of a rare complication

Mechanical thrombectomy is now a recommended treatment for large vessel occlusion in acute ischemic stroke. However, it is associated with a number of complications, which need to be minimized and effectively managed to maximize the benefits of thrombectomy. We describe an unusual and rare complication of microcatheter fracture after a successful thrombectomy for middle cerebral artery occlusion. Due to a lack of possibilities to remove it, we decided to manage it conservatively. Subsequently, the microcatheter fragment did not interrupt normal blood flow through the artery, and the patient has been doing well without neurological sequelae. Systematic reporting of such complications will aid in the design and development of thrombectomy devices in the future.

A fully automatic method for vascular tortuosity feature extraction in the supra-aortic region: unraveling possibilities in stroke treatment planning.

Vascular tortuosity of supra-aortic vessels is widely considered one of the main reasons for failure and delays in endovascular treatment of large vessel occlusion in patients with acute ischemic stroke. Characterization of tortuosity is a challenging task due to the lack of objective, robust and effective analysis tools. We present a fully automatic method for arterial segmentation, vessel labelling and tortuosity feature extraction applied to the supra-aortic region. A sample of 566 computed tomography angiography scans from acute ischemic stroke patients (aged 74.8±12.9, 51.0% females) were used for training, validation and testing of a segmentation module based on a U-Net architecture (162 cases) and a vessel labelling module powered by a graph U-Net (566 cases). Successively, 30 cases were processed for testing of a tortuosity feature extraction module. Measurements obtained through automatic processing were compared to manual annotations from two observers for a thorough validation of the method. The proposed feature extraction method presented similar performance to the inter-rater variability observed in the measurement of 33 geometrical and morphological features of the arterial anatomy in the supra-aortic region. This system will contribute to the development of more complex models to advance the treatment of stroke by adding immediate automation, objectivity, repeatability and robustness to the vascular tortuosity characterization of patients.

Emergency Angioplasty or Stenting for Stroke Patients with Intracranial Atherosclerotic Large Vessel Occlusion.

Mechanical thrombectomy (MT) has become the gold standard for the treatment of large vessel occlusion (LVO) in acute ischemic stroke. However, it remains controversial whether emergency angioplasty or stenting in patients with intracranial atherosclerotic stenosis (ICAS) should be adopted. Thus, we performed a retrospective analysis of clinical data to determine whether emergency angioplasty or stenting is necessary. We retrospectively analyzed data from patients undergoing MT with ICAS-related LVO of the acute anterior circulation between 2017 and 2019. Eligible patients were divided into two treatment groups: those who received rescue angioplasty or stenting [Patients treated with rescue angioplasty or stenting (PTAS) group] and those who received thrombectomy alone (non-PTAS group). The primary outcomes were good prognosis at 90 days (mRS: 0-2). Mortality, symptomatic intracranial hemorrhage, and reocclusion rate were evaluated as secondary outcomes. A total of 184 patients with severe stenosis after MT were enrolled, including 64 patients receiving rescue angioplasty or stenting and 120 patients without rescue angioplasty or stenting. Compared with the non-PTAS group, a better functional outcome (mRS0-2) (51.6% vs. 35.0%, adjusted odds ratio: 2.11, 95% confidence interval [CI]: 1.22-4.29; P=0.02), lower 7-day National Institutes of Health Stroke Scale [6 (3-12.75) vs. 10 (4-16); P=0.04], lower 24-h neurological deterioration rate (7.8% vs. 21.7%, P=0.02), and lower 24-h reocclusion rate were observed in the PTAS group (6.3% vs. 17.5%, P=0.03). There were no significant differences in mortality or incidence of symptomatic intracerebral hemorrhage. Emergency angioplasty or stenting could be a safe and feasible therapeutic option with better outcomes for stroke patients with ICAS-related LVO.

Abstract WMP82: National Trends In Endovascular Therapy For Intracranial Atherosclerotic Disease 2008-2019

Introduction: Endovascular therapy is a treatment option for patients with severe symptomatic intracranial atherosclerotic disease (ICAD). The utilization of angioplasty and stenting has varied since the development of stents for this disease in 2005. This study assesses the longitudinal trends for endovascular treatment of ICAD in the U.S. Methods: We performed a data search from the National Inpatient Sample (NIS) database using ICD9 and ICD10 procedure codes from 2008 through 2019. Data was collected for patients with stroke from ICAD who underwent stenting or angioplasty alone. We also assessed the utilization of stenting or angioplasty in thrombectomy cases for large vessel occlusion (LVO), the use of drug eluting stents, patient demographics, regional trends, length of stay, and mortality statistics. Results: Between 2008 and 2019, the nadir of ICAD stenting cases in the U.S. was in 2011 (n=242). There was over a 207% increase in stenting cases in 2015 (n=730), and another increase of 47% in ICAD stenting in 2018 and 2019 (2018=965, 2019=1,175). There was a significant increase in stenting for ICAD over the entire study period (p=0.003). The data also shows a significant increase in the use of stenting as adjunctive therapy to thrombectomy for LVO. In 2011, stenting with thrombectomy in LVO represented 17.8% (43/242) of patients stented with stroke from ICAD. In 2019, these cases represented 48.1% (565/1,175) of the patients stented. Over the study period, this increase in stent use during LVO treatment was significant (p&lt;0.001). Angioplasty alone for ICAD in non-occluded vessels has not significantly changed (p=0.289). Angioplasty as an adjunct to thrombectomy for LVO has steadily increased over the past 10 years, with 94 cases in 2008 and 210 cases in 2019, representing a 123% increase. Conclusion: There has been a progressive increase in stenting for ICAD since the nadir of this procedure in 2011 which is statistically significant. This increase was seen in patients with severe symptomatic ICAD, but also in patients undergoing thrombectomy for acute LVO with ICAD. Positive clinical stenting trials such as WEAVE and the post-hoc analysis from SAMMPRIS, and the increase in endovascular therapy for LVO appear temporally related to these changes.