Abstract Number ‐ 142: Flow Diversion for Posterior Communicating Artery Aneurysms: Systematic Review and Meta‐Analysis

Introduction Posterior communicating artery (PComA) aneurysms are common and have a high risk of rupture. Flow diverters (FD) have demonstrated a safe and effective profile. However, the use of FD in PComA aneurysms has shown controversial results with high rates of recurrence and a high risk of potential ischemic complications. There, we aimed to evaluate the safety and efficacy of flow diversion for the treatment of PComA aneurysms with a meta‐analysis of the literature. Methods We performed a systematic search in Scopus, Embase, Medline, and Web of Science from inception until May 2022 for all the studies that reported the safety and effectiveness of FD for the treatment of intracranial aneurysms located in the posterior communicating artery. The primary effectiveness endpoint was a complete aneurysm occlusion rate at final follow‐up. The primary safety endpoint was a composite measure of cumulative events that occurred during and after the procedure. Events included death and ischemic/hemorrhagic complications. Random‐effects meta‐analysis was used to calculate proportions. Statistical heterogeneity across studies was assessed with I2 statistics. Results A total of 13 studies with 397 patients harboring 403 aneurysms were included in our analysis. Mean age was 48 years and mean aneurysm size was 5.3 mm. Complete aneurysm occlusion at final follow‐up was 74% (95% CI 66–81%; I2 = 54%). The primary safety composite outcome was 5% (95% CI 3–9%; I2 = 0%). The mortality rate was 1% (95% CI 0–2%; I2 = 0%). Subgroup analysis showed that patients with a non‐fetal PComA had a higher rate (76%; 95% CI 62%‐86%; I2 = 53%) of complete aneurysm occlusion compared to those with a fetal PComA (36%; 95% CI 21%‐54%; I2 = 0%). Conclusions Our findings show that flow diversion for the treatment of aneurysms located in the PComA is effective and safe. However, the same treatment for aneurysms located in a fetal‐type PComA did not show the same efficacy profile suggesting that these cases might require an alternative treatment to achieve permanent occlusion rates

Abstract Number ‐ 21: Mechanical Thrombectomy versus Medical Management in Patients with acute LVO and Pre‐morbid Disability: Meta‐analysis

Introduction Actual guidelines offer little guidance for endovascular treatment of patients with acute ischemic stroke (AIS) and pre‐morbid disability (PMD). Often, patients with a mRS >2 are not considered for mechanical thrombectomy (MT) and might not be given the best chance of achieving recovery. Three recent meta‐analysis have showed conflicting results regarding the benefit of MT, while persistently showing a significant increase in mortality. Methods We conducted a systematic search in Embase, Medline, and Web of Science for studies of patients with AIS and PMD who were treated with MT or MM. We included all definitions of PMD, main outcomes were favorable functionality at 90‐days (mRS 0–2 or return to baseline mRS), symptomatic ICH, and mortality. We performed meta‐analyses using a random‐effect model, and I2 to evaluate heterogeneity. Subgroup analyses were used when appropriate. Results 2 studies contained data comparing PMD patients treated with MT versus MM, 14 studies contained data only of patients treated with MT, and 10 only of patients treated with MM; they provided data of 1071 patients in the MT group and 4547 in the MM group. Pooled rates in the MT group were 28% (95% CI 0.24‐0.32) for favorable functionality, 7% (95% CI 0.04‐0.12) for sICH, 43% (95% CI 0.36‐0.51) for 90‐days mortality, 18% (95% CI 0.14‐0.23) for intra‐hospital mortality, and pooled reperfusion rate (mTICI 0–2) of 80% (95% CI 0.72‐0.86). In a meta‐analysis of proportion with the treatments modalities as subgroups, including only studies with a similar definition of PMD, we obtained: for favorable functionality, MT = 26% (95% CI 0.23‐0.30) vs. MM = 35% (95% CI 0.22‐0.51); for sICH, MT = 6% (95% CI 0.05‐0.08) vs. MM = 6% (95% CI 0.05‐0.08); for 90‐days mortality, MT = 48% (95% CI 0.44‐0.52) vs. MM = 34% (95% CI 0.27‐0.41); and for in‐hospital mortality, MT = 18% (95% CI 0.14‐0.23) vs. MM = 22% (95% CI 0.17‐0.28). Additionally, meta‐analysis for 90‐days mortality in MT studies, showed a pooled rate of 49% (95% CI 0.45‐0.53) for the high tPA rate subgroup, and 30% (95% CI 0.19‐0.44) for the low tPA rate subgroup. Conclusions Up to one third of PMD patients who undergo MT might achieve favorable functionality, without increasing the risk of sICH and with rates similar to those obtained with MM. Furthermore, we observed a high 90‐day mortality rate, in both MT and MM groups. In subgroups exploration, there is trend of high tPA rates to be associated with the increased mortality. It is urgent to identify PMD patients who will benefit from MT and factors associated with poor outcomes

Abstract Number ‐ 210: Curative Embolization of Ruptured Pediatric Cerebral Arteriovenous Malformations

Introduction The incidence of ruptured cerebral arteriovenous malformations (AVMs) has increased as a consequence of the publication of the ARUBA trial. In the setting of ruptured AVMs, target embolization of high‐risk features can be considered to decrease the risk for recurrent hemorrhage. However, embolization with the intention to cure has not been well studied in ruptured AVMs. Furthermore, the role of primary curative embolization of pediatric AVMs is uncertain. Hence, we aimed to characterize the safety and efficacy of curative embolization for ruptured AVMs in pediatric patients. Methods Between 2010 and 2022, a retrospective analysis of all pediatric (≤18 years) patients who underwent curative embolization for ruptured AVMs was conducted in two institutions. Demographic data, clinical presentation, Spetzler‐Martin (SM) grade, associated high‐risk vascular structures, and procedural characteristics were retrieved. The safety (intraprocedural complications and mortality) and efficacy (complete angiographic obliteration after the last embolization session) were evaluated. Results Sixty‐eight patients (38 females; mean age 12.4 ± 3.4 years) underwent a total of 109 embolization sessions. The most frequent clinical presentation was headache (79%). There were 15 (22%) SM grade I lesions, 34 (51%) grade II, 14 (21%) grade III, and 4 (6%) grade IV. In 21 patients, twenty‐three high‐risk structures were observed (3 prenidal aneurysms, 12 intranidal aneurysms, 3 venous aneurysms, 2 varicose veins, 3 arteriovenous fistulae). Decompressive craniectomy with intracerebral hemorrhage evacuation was performed in 15 patients (22%). The mean number of sessions per patient was 1.6 (range 1 to 6) and n‐butyl cyanoacrylate was the most used embolic agent (30%). The transarterial approach was the most common (91%). The mean volume of embolic agents in each patient was 2.1 ml (range 0.1 to 6 ml). Seventeen intraprocedural complications (16% of procedures) were observed and no deaths were reported. In patients with high‐risk structures the rate of intraprocedural complications was 24%. The most common complication was microcatheter‐related vessel perforation (7%). Complete angiographic obliteration was achieved in 42 patients (62%). In 30 patients (44%) the AVM was occluded with a single embolization session. The rate of complete obliteration in patients with high‐risk structures was 62%. Conclusions Curative embolization of ruptured pediatric AVMs shows a high rate of intraprocedural complications, especially when high‐risk associated vascular structures are present. In addition, acceptable complete obliteration rates were found. Appropriate long‐term follow‐up in prospective studies tailored to the pediatric population are required to determine the best therapeutic approach

Abstract Number ‐ 45: Curative Embolization for Pediatric Low‐Grade Brain Arteriovenous Malformations

Introduction Improvements in the safety and efficacy of curative embolization for brain arteriovenous malformations (bAVMs) have allowed to achieve comparable results to microsurgical resection and radiosurgery, especially for low‐grade bAVMs (Spetzler Martin [SM] grade I and II). However, whether this treatment modality is beneficial in the pediatric population remains unknown. Hence, we assessed the safety and efficacy of curative embolization for low‐grade bAVMs in children. In addition, we determined predictors of intraprocedural complications and predictors of complete occlusion in one embolization session. Methods Between 2010 and 2022, a retrospective analysis of all pediatric (≤18 years) patients who underwent curative embolization for low‐grade bAVMs was conducted at two institutions. Demographic data, clinical presentation, SM grade, and procedural characteristics were retrieved. The safety (intraprocedural complications and mortality) and efficacy (complete angiographic obliteration after the last embolization session) were evaluated. Multivariable logistic regression analysis was performed to identify potential predictive factors of intraprocedural complications and complete occlusion in one session. For selected variables, odds ratios (OR) with 95% confidence intervals (CI) and p value of the likelihood‐ratio test were presented. Results Sixty‐eight patients (41 females; mean age 12.9 ± 3.6 years) underwent a total of 102 embolization sessions. Fifty‐one bAVMs (75%) presented ruptured, and headache was the most common clinical presentation (50%). There were 24 (35%) SM grade I lesions and 44 (65%) grade II. Onyx was the most used embolic agent (33%) and the transarterial approach was the most common (93%). The mean volume of embolic agents in each patient was 2.4 ml (range 0.2 to 7.5 ml). Fourteen intraprocedural complications (14% of procedures) were observed and no deaths were reported. The most common complication was microcatheter‐related vessel perforation (6%). Single venous drainage decreased the risk of intraprocedural complications (OR = 0.19; 95% CI 0.04 – 0.78). Complete angiographic obliteration was achieved in 44 patients (65%). In 35 patients (52%) the bAVM was occluded with a single session. A small bAVM size was predictor of complete occlusion in one session (OR = 0.42; 95% CI 0.21 – 0.73). Conclusions Curative embolization in pediatric low‐grade bAVMs can be performed with an acceptable complete occlusion rate but with a high rate of intraprocedural complications. The risk of intraprocedural complications was low in bAVMs with a single venous drainage. The odds of complete occlusion in one session are high in small bAVMs. Curative embolization should be selected on an individual basis in order to achieve optimal results

Abstract 039: Angiographic Outcomes of Woven EndoBridge and Balloon‐Assisted Coiling for the Treatment of Ruptured Wide‐Necked Aneurysms

Introduction The optimal endovascular approach for wide‐neck intracranial aneurysms (IAs) during the acute phase of bleeding remains uncertain, and the use of stent‐assisted coiling or flow diversion is controversial due to antiplatelet therapy requirements and potential risks (1, 2). Various techniques have been developed to address these challenges, including balloon‐assisted coiling (BAC) and intrasaccular flow‐disruption. The Woven EndoBridge (WEB) is a flow disrupter that has gained popularity in treating ruptured IAs due to its effectiveness in occluding aneurysms with minimal rebleeding (3, 4). The aim of this study is to provide outcome comparisons between WEB and BAC in a specific cohort of patients with ruptured wide‐necked IAs. Methods In this international cohort study, we included consecutive patients treated for ruptured wide‐neck IAs with either WEB or BAC at three neurovascular centers. The primary effectiveness outcome was complete aneurysm occlusion at the final imaging follow‐up using the Raymond‐Roy (RR) occlusion classification. Secondary outcomes included favorable functional outcome and periprocedural hemorrhagic/ischemia‐related complications. Comparisons were performed using multivariable logistic and ordinal regressions. Results One hundred four patients treated with WEB and 107 patients treated with BAC were included. The mean length of imaging follow‐up was 17.5 (± 17.6) months in the WEB group and 11.8 (± 10.3) months in the BAC group (p = 0.142). Of the patients, 60.5% in the WEB group and 53% in the BAC group achieved complete occlusion, with no significant difference between the two groups after adjusting for covariates (adjusted OR [aOR] = 1.02; 95% CI 0.46 – 2.25; p = 0.964). The odds of favorable functional outcome did not significantly differ between the WEB (74.8%) and BAC groups (77.4%, aOR = 1.45; 95% CI 0.65 – 3.24; p = 0.368). Procedure‐related complications were similar in both groups (WEB: 9.6%, BAC: 10.3%, p = 0.872). There was no statistically significant difference observed in the rates of ischemic events (WEB: 6.7% vs. BAC: 2.8%, p = 0.180) and hemorrhagic events (WEB: 3.8% vs. BAC: 7.5%, p = 0.255) between the two groups. Conclusion In conclusion, both WEB and BAC techniques showed similar effectiveness and safety outcomes in treating ruptured wide‐neck IAs. Further research and direct comparative studies are needed to better guide treatment decisions for this patient population

Safety Outcomes of Antiplatelet Therapy During Endovascular Treatment of Tandem Lesions in Acute Ischemic Stroke Patients

Risk of hemorrhage remains with antiplatelet medications required with carotid stenting during endovascular therapy (EVT) for tandem lesion (TLs). We evaluated the safety of antiplatelet regimens in EVT of TLs. This multicenter study included anterior circulation TL patients from 2015 to 2020, stratified by periprocedural EVT antiplatelet strategy: (1) no antiplatelets, (2) single oral, (3) dual oral, and (4) intravenous IV (in combination with single or dual oral). Primary outcome was symptomatic intracranial hemorrhage (sICH). Secondary outcomes were any hemorrhage, favorable functional status (mRS 0-2) at 90 days, successful reperfusion (mTICI score ≥ 2b), in-stent thrombosis, and mortality at 90 days. Of the total 691 patients, 595 were included in the final analysis. One hundred and nineteen (20%) received no antiplatelets, 134 (22.5%) received single oral, 152 (25.5%) dual oral, and 196 (31.9%) IV combination. No significant association was found for sICH (ref: no antiplatelet: 5.7%; single:4.2%; aOR 0.64, CI 0.20-2.06, p = 0.45, dual:1.9%; aOR 0.35, CI 0.09-1.43, p = 0.15, IV combination: 6.1%; aOR 1.05, CI 0.39-2.85, p = 0.92). No association was found for parenchymal or petechial hemorrhage. Odds of successful reperfusion were significantly higher with dual oral (aOR 5.85, CI 2.12-16.14, p = 0.001) and IV combination (aOR 2.35, CI 1.07-5.18, p = 0.035) compared with no antiplatelets. Odds of excellent reperfusion (mTICI 2c/3) were significantly higher for cangrelor (aOR 4.41; CI 1.2-16.28; p = 0.026). No differences were noted for mRS 0-2 at 90 days, in-stent thrombosis, and mortality rates. Administration of dual oral and IV (in combination with single or dual oral) antiplatelets during EVT was associated with significantly increased odds of successful reperfusion without an increased rate of symptomatic hemorrhage or mortality in patients with anterior circulation TLs

Safety Outcomes of Mechanical Thrombectomy Versus Combined Thrombectomy and Intravenous Thrombolysis in Tandem Lesions

Background: We aimed to describe the safety and efficacy of mechanical thrombectomy (MT) with or without intravenous thrombolysis (IVT) for patients with tandem lesions and whether using intraprocedural antiplatelet therapy influences MT\u27s safety with IVT treatment. Methods: This is a subanalysis of a pooled, multicenter cohort of patients with acute anterior circulation tandem lesions treated with MT from 16 stroke centers between January 2015 and December 2020. Primary outcomes included symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2. Additional outcomes included hemorrhagic transformation, successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b-3), complete reperfusion (modified Thrombolysis in Cerebral Infarction score 3), favorable functional outcome (90-day modified Rankin Scale score 0-2), excellent functional outcome (90-day modified Rankin Scale score 0-1), in-hospital mortality, and 90-day mortality. Results: Of 691 patients, 512 were included (218 underwent IVT+MT and 294 MT alone). There was no difference in the risk of sICH (adjusted odds ratio [aOR], 1.22 [95% CI, 0.60-2.51]; P=0.583), parenchymal hematoma type 2 (aOR, 0.99 [95% CI, 0.47-2.08]; P=0.985), and hemorrhagic transformation (aOR, 0.95 [95% CI, 0.62-1.46]; P=0.817) between the IVT+MT and MT alone groups after adjusting for confounders. Administration of IVT was associated with an increased risk of sICH in patients who received intravenous antiplatelet therapy (aOR, 3.04 [95% CI, 0.99-9.37]; P=0.05). The IVT+MT group had higher odds of a 90-day modified Rankin Scale score 0 to 2 (aOR, 1.72 [95% CI, 1.01-2.91]; P=0.04). The odds of successful reperfusion, complete reperfusion, 90-day modified Rankin Scale score 0 to 1, in-hospital mortality, or 90-day mortality did not differ between the IVT+MT versus MT alone groups. Conclusions: Our study showed that the combination of IVT with MT for tandem lesions did not increase the overall risk of sICH, parenchymal hematoma type 2, or overall hemorrhagic transformation independently of the cervical revascularization technique used. However, intraprocedural intravenous antiplatelet therapy during acute stent implantation might be associated with an increased risk of sICH in patients who received IVT before MT. Importantly, IVT+MT treatment was associated with a higher rate of favorable functional outcomes at 90 days

Clinical and Safety Outcomes of Endovascular Therapy 6 to 24 Hours After Large Vessel Occlusion Ischemic Stroke With Tandem Lesions

Background and Purpose Effect of endovascular therapy (EVT) in acute large vessel occlusion (LVO) patients with tandem lesions (TLs) within 6-24 hours after last known well (LKW) remains unclear. We evaluated the clinical and safety outcomes among TL-LVO patients treated within 6-24 hours. Methods This multicenter cohort was divided into two groups, based on LKW to puncture time: early window (\u3c6 hours), and late window (6-24 hours). Primary clinical and safety outcomes were 90-day functional independence measured by the modified Rankin Scale (mRS: 0-2) and symptomatic intracranial hemorrhage (sICH). Secondary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), first-pass effect, early neurological improvement, ordinal mRS, and in-hospital and 90-day mortality. Results Of 579 patients (median age 68, 32.1% females), 268 (46.3%) were treated in the late window and 311 (53.7%) in the early window. Late window group had lower median National Institutes of Health Stroke Scale score at admission, Alberta Stroke Program Early Computed Tomography Score, rates of intravenous thrombolysis, and higher rates for perfusion imaging. After adjusting for confounders, the odds of 90-day mRS 0-2 (47.7% vs. 45.0%, adjusted odds ratio [aOR] 0.71, 95% confidence interval [CI] 0.49-1.02), favorable shift in mRS (aOR 0.88, 95% CI 0.44-1.76), and sICH (3.7% vs. 5.2%, aOR 0.56, 95% CI 0.20-1.56) were similar in both groups. There was no difference in secondary outcomes. Increased time from LKW to puncture did not predicted the probability of 90-day mRS 0-2 (aOR 0.99, 95% CI 0.96-1.01, for each hour delay) among patients presenting \u3c24 hours. Conclusion EVT for acute TL-LVO treated within 6-24 hours after LKW was associated with similar rates of clinical and safety outcomes, compared to patients treated within 6 hours

Abstract 1122‐000227: Stenting Versus Medical Treatment for Chronic Internal Carotid Artery Occlusions: A Systematic Review and Meta‐analysis

Introduction: Chronic internal carotid occlusion is responsible for 10–15% ischemic strokes or transit ischemic attacks (TIA). Subsequent ipsilateral ischemic stroke rate is 5.9% per year. However, this risk can increase up to 23% in two years in a subgroup of patients with poor collaterals regardless of medical therapy with antiplatelet or anticoagulant agents. Prevention of subsequent stroke in patients with carotid artery occlusion remains a difficult challenge. Carotid artery stenting (CAS) has recently been considered in its management. However, there is ambiguity on its safety. We aim to evaluate the safety and feasibility of CAS and compared it with medical management. Methods: We performed a systematic review and meta‐analysis to compare long‐term outcome (stroke recurrence) of current carotid occlusion treatments (CAS vs medical therapy). Two independent reviewers performed the screening, data extraction, and quality assessment. A random effects model was used for analysis. Results: A total of 5720 studies were screened. Of these, 11 studies were included in our systematic review and meta‐analysis of proportions. The CAS group has lower proportions of recurrent strokes (5% vs 30%,) after 30 days than medical therapy alone. Additionally, the proportion of periprocedural intracranial hemorrhage was 4.4% (95% CI 2.5 to 6.8) in the CAS group. Conclusions: CAS of the chronically occluded cervical ICA seems to be a safe procedure with lower rates of recurrent stroke in clinical follow up. Future randomized studies are warranted to guide the optimal management of this complex disease

Abstract 220: Transradial Access Versus Transfemoral Approach for Carotid Artery Stenting: A Systematic Review and Meta‐analysis

Introduction Carotid artery stenting (CAS) has emerged as a viable alternative to carotid endarterectomy for managing carotid artery stenosis in high‐risk patients (1). While the transfemoral arterial approach (TF) remains the preferred method, it is associated with inherent limitations and potential complications (2‐4). Consequently, exploring the transradial artery access (TR) as a potential option becomes crucial in optimizing patient outcomes and procedural success rates. Limited data exists comparing the outcomes of TR approach in CAS to TF approach. This study aims to systematically review and meta‐analyze the outcomes and complication rates between TR and TF access for CAS. Methods A systematic electronic search was conducted in four databases up to May 10th, 2023. Studies with randomized or non‐randomized designs, involving CAS through TR or TF approach, were included. Outcomes of interest were stroke, transient ischemic attack (TIA), death, myocardial infarction (MI), and access site complications. A meta‐analysis was performed, analyzing pooled odds ratios (ORs) and 95% confidence intervals (CI) to assess the effect size of the vascular access approaches. Results Six studies with a total of 6,917 patients were included, out of which 602 (8.7%) underwent the TR approach, and 6,315 (91.3%) underwent the TF approach. Meta‐analysis results showed no significant difference in stroke occurrence between TR and TF groups (TR: 1.7% vs. TF: 1.9%; OR = 0.98; 95% CI 0.49 – 1.96; I2 = 0%). Similarly, no significant difference was found in death (TR: 1% vs. TF: 0.9%; OR = 0.95; 95% CI 0.38 – 2.37; I2 = 0%), MI (TR: 0.2% vs. TF: 0.3%; OR = 1.53; 95% CI 0.20 – 11.61; I2 = 0%), TIA (TR: 0.4% vs. TF: 1%; OR = 0.46; 95% CI 0.11 – 1.95; I2 = 0%), and access site complications (TR: 2.2% vs. TF: 1%; OR = 0.97; 95% CI 0.48 – 1.98; I2 = 0%). Conclusion In the comparison of TR and TF approaches for CAS, no significant differences were observed in stroke, death, MI, TIA, or access site complications. TR approach shows promise as an alternative method for CAS, offering potential benefits without increased risk of complications. However, further studies are needed to confirm these findings and establish guidelines for optimal access site selection