Association of preprocedural antiplatelet use with decreased thromboembolic complications for intracranial aneurysms undergoing intrasaccular flow disruption

OBJECTIVE

This study was conducted to investigate the impact of antiplatelet administration in the periprocedural period on the occurrence of thromboembolic complications (TECs) in patients undergoing treatment using the Woven EndoBridge (WEB) device for intracranial wide-necked bifurcation aneurysms. The primary objective was to assess whether the use of antiplatelets in the pre- and postprocedural phases reduces the likelihood of developing TECs, considering various covariates.

METHODS

A retrospective multicenter observational study was conducted within the WorldWideWEB Consortium and comprised 38 academic centers with endovascular treatment capabilities. Univariable and multivariable logistic regression analyses were performed to determine the association between antiplatelet use and TECs, adjusting for covariates. Missing predictor data were addressed using multiple imputation.

RESULTS

The study comprised two cohorts: one addressing general thromboembolic events and consisting of 1412 patients, among whom 103 experienced TECs, and another focusing on symptomatic thromboembolic events and comprising 1395 patients, of whom 50 experienced symptomatic TECs. Preprocedural antiplatelet use was associated with a reduced likelihood of overall TECs (OR 0.32, 95% CI 0.19-0.53, p < 0.001) and symptomatic TECs (OR 0.49, 95% CI 0.25-0.95, p = 0.036), whereas postprocedural antiplatelet use showed no significant association with TECs. The study also revealed additional predictors of TECs, including stent use (overall: OR 4.96, 95% CI 2.38-10.3, p < 0.001; symptomatic: OR 3.24, 95% CI 1.26-8.36, p = 0.015), WEB single-layer sphere (SLS) type (overall: OR 0.18, 95% CI 0.04-0.74, p = 0.017), and posterior circulation aneurysm location (symptomatic: OR 18.43, 95% CI 1.48-230, p = 0.024).

CONCLUSIONS

The findings of this study suggest that the preprocedural administration of antiplatelets is associated with a reduced likelihood of TECs in patients undergoing treatment with the WEB device for wide-necked bifurcation aneurysms. However, postprocedural antiplatelet use did not show a significant impact on TEC occurrence.

Elucidating the pathogenesis behind arteriovenous malformations of the central nervous system: a bibliometric analysis

Arteriovenous malformations (AVMs) are vascular malformations of the central nervous system (CNS) with potential for significant consequences. The exact pathophysiologic mechanism of AVM formation is not fully understood. This study aims to evaluate bibliometric parameters and citations of the literature of AVMs to provide an overview of how the field has evolved. We performed an electronic search on Web of Science to identify the top 100 published and indexed articles with the highest number of citations discussing the pathogenesis of AVMs. This study yielded 1863 articles, of which the top 100 were selected based on the highest total citation count. These articles included 24% basic science, 46% clinical, and 30% review articles. The most-cited article was a clinical article from 2003, and the most recent was published in 2022. The median number of authors was 6, with the highest being 46 for a clinical article. The top 5 journals were identified, with the highest impact factor being 20.1. 13 countries were identified, with the US contributing the most articles (approximately 70%). Regarding genes of investigation, VEGF was one of the early genes investigated, while more interested in RAS/MAPK has been garnered since 2015. There is a growing interest in AVM genomics and pathogenesis research. While progress has been made in understanding clinical aspects and risk factors, the exact pathophysiological mechanisms and genetic basis of AVM formation remain incompletely understood. Further investigation of key genes in AVM pathogenesis can allow identification of potential therapeutic targets.

Dual Layer vs Single Layer Woven EndoBridge Device in the Treatment of Intracranial Aneurysms: A Propensity Score-Matched Analysis

BACKGROUND

The Woven EndoBridge (WEB) devices have been used for treating wide neck bifurcation aneurysms (WNBAs) with several generational enhancements to improve clinical outcomes. The original device dual-layer (WEB DL) was replaced by a single-layer (WEB SL) device in 2013. This study aimed to compare the effectiveness and safety of these devices in managing intracranial aneurysms.

METHODS

A multicenter cohort study was conducted, and data from 1,289 patients with intracranial aneurysms treated with either the WEB SL or WEB DL devices were retrospectively analyzed. Propensity score matching was utilized to balance the baseline characteristics between the two groups. Outcomes assessed included immediate occlusion rate, complete occlusion at last follow-up, retreatment rate, device compaction, and aneurysmal rupture.

RESULTS

Before propensity score matching, patients treated with the WEB SL had a significantly higher rate of complete occlusion at the last follow-up and a lower rate of retreatment. After matching, there was no significant difference in immediate occlusion rate, retreatment rate, or device compaction between the WEB SL and DL groups. However, the SL group maintained a higher rate of complete occlusion at the final follow-up. Regression analysis showed that SL was associated with higher rates of complete occlusion (OR: 0.19; CI: 0.04 to 0.8, p = 0.029) and lower rates of retreatment (OR: 0.12; CI: 0 to 4.12, p = 0.23).

CONCLUSION

The WEB SL and DL devices demonstrated similar performances in immediate occlusion rates and retreatment requirements for intracranial aneurysms. The SL device showed a higher rate of complete occlusion at the final follow-up.

Factors influencing geographic gender disparity in neurosurgery: a nationwide geospatial clustering analysis

OBJECTIVE

Women neurosurgeons (WNs) continue to remain a minority in the specialty despite significant initiatives to increase their representation. One domain less explored is the regional distribution of WNs, facilitated by the hiring practices of neurosurgical departments across the US. In this analysis, the authors coupled the stated practice location of WNs with regional geospatial data to identify hot spots and cold spots of prevalence and examined regional predictors of increases and decreases in WNs over time.

METHODS

The authors examined the National Provider Identifier (NPI) numbers of all neurosurgeons obtained via the National Plan and Provider Enumeration System (NPPES), identifying the percentage of WNs in each county for which data were appended with data from the US Census Bureau. Change in WN rates was identified by calculating a regression slope for all years included (2015-2022). Hot spots and cold spots of WNs were identified through Moran's clustering analysis. Population and surgeon features were compared for hot spots and cold spots.

RESULTS

WNs constituted 10.73% of all currently active neurosurgical NPIs, which has increased from 2015 (8.81%). Three hot spots were found-including the Middle Atlantic and Pacific divisions-that contrasted with scattered cold spots throughout the East Central regions that included Memphis as a major city. Although relatively rapidly growing, hot spots had significant gender inequality, with a median WN percentage of 11.38% and a median of 0.61 WNs added to each respective county per year.

CONCLUSIONS

The authors analyzed the prevalence of WNs by using aggregated data from the NPPES and US Census Bureau. The authors also show regional hot spots of WNs and that the establishment of WNs in a region is a predictor of additional WNs entering the region. These data suggest that female neurosurgical mentorship and representation may be a major driver of acceptance and further gender diversity in a given region.

Association of moyamoya vasculopathy with autoimmune disease: a systematic review and pooled analysis

Despite more than six decades of extensive research, the etiology of moyamoya disease (MMD) remains unknown. Inflammatory or autoimmune (AI) processes have been suggested to instigate or exacerbate the condition, but the data remains mixed. The objective of the present systematic review was to summarize the available literature investigating the association of MMD and AI conditions as a means of highlighting potential treatment strategies for this subset of moyamoya patients. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, Embase, Scopus, Web of Science, and Cochrane databases were queried to identify studies describing patients with concurrent diagnoses of MMD and AI disease. Data were extracted on patient demographics, clinical outcomes, and treatment. Stable or improved symptoms were considered favorable outcomes, while worsening symptoms and death were considered unfavorable. Quantitative pooled analysis was performed with individual patient-level data. Of 739 unique studies identified, 103 comprising 205 unique patients (80.2% female) were included in the pooled analysis. Most patients (75.8%) identified as Asian/Pacific Islanders, and the most commonly reported AI condition was Graves' disease (57.6%), with 55.9% of these patients presenting in a thyrotoxic state. Of the 148 patients who presented with stroke, 88.5% of cases (n = 131) were ischemic. Outcomes data was available in 152 cases. There were no significant baseline differences between patients treated with supportive therapy alone and those receiving targeted immunosuppressant therapy. Univariable logistic regression showed that surgery plus medical therapy was more likely than medical therapy alone to result in a favorable outcome. On subanalysis of operated patients, 94.1% of patients who underwent combined direct and indirect bypass reported favorable outcomes, relative to 76.2% of patients who underwent indirect bypass and 82% who underwent direct bypass (p < 0.05). On univariable analysis, the presence of multiple AI disorders was associated with worse outcomes relative to having a single AI disorder. Autoimmune diseases have been uncommonly reported in patients with MMD, but the presence of multiple AI comorbidities portends poorer prognosis. The addition of surgical intervention appears to improve outcomes and for patients deemed surgical candidates, combined direct and indirect bypass appears to offer better outcomes that direct or indirect bypass alone.

Abstract 80: Hospital Cost Of Direct To Angiography Suite Compared To Emergency Department Transfers For Large Vessel Occlusions Undergoing Mechanical Thrombectomy: A Propensity Adjusted Analysis

Introduction: Direct-to-angiography-suite (DTAS) transfer for patients with large vessel occlusions (LVOs) undergoing mechanical thrombectomy is associated with decreased workflow times and improved neurological outcomes. Herein, we sought to demonstrate a decrease in hospital cost associated with DTAS compared to emergency department (ED) transfers for patient undergoing mechanical thrombectomy for an LVO.

Methods: A retrospective analysis was performed on all patients who underwent mechanical thrombectomy for an LVO at a single comprehensive stroke center from 2017 to 2021. All patients who were transferred DTAS or ED were included. Total hospital cost (sum of overhead, professional, diagnostic, and room charges throughout the entire index patient admission) was obtained from the hospital financial department for the index admission. A propensity adjusted (matched for age, sex, vessel occluded, co-morbidities, BMI, admission NIHSS, access site, and use of a stent retriever) was implemented. Mean difference in hospital cost was the primary outcome.

Results: During the study period, 341 patients underwent mechanical thrombectomy for an LVO. Of these patients, 140 (41%) were transferred DTAS and 96 (28%) to the ED. There were no significant differences between cohorts in terms of age, sex, vessel occluded, admission NIHSS, co-morbidities, number of passes, TICI score, access site, stent retriever, major complications, or in-hospital mortality. The DTAS cohort ($33,061, sD $17,258) had a significantly lower hospital cost compared to ED transferred patients ($38,030, sD $18,572) (p=0.04). There was no significant difference between the ED (12.2, sD 11.8) and DTAS (11.6, sD 11.1) cohorts in discharge NIHSS. Following propensity score adjustment, linear regression analysis found DTAS (compared to ED transfer) to be significantly associated with a decrease in hospital cost ($-6,344; 95% CI: $-11,067 to $-1,623; p=0.009).

Conclusion: DTAS transfer for patients undergoing an acute mechanical thrombectomy for a LVO was associated with a greater than $6,000 decrease total hospital cost compared to patients first transferred to the ED. The present study further supports DTAS transfer for patients undergoing mechanical thrombectomy for LVO.

Abstract 135: Number-needed-to-review: A Novel Metric To Assess Triage Efficiency Of Large Vessel Occlusion Detection Systems

Background: Endovascular thrombectomy is the gold standard treatment for acute ischemic strokes with large vessel occlusions (LVO). Manual image analysis is often time consuming and requires clinicians to be skilled in reading perfusion scans, as well as vessel images. RapidAI software has an automated processor to detect LVO of the middle cerebral artery and is analyzed in this study. A novel metric, number-needed-to-review (NNR), is introduced to assess the clinical efficiency of this software.

Methods: This is a retrospective review of patients with a suspected ischemic stroke and an image processed by RapidAI software from 11/1/2020 to 4/30/2021 at a regional hospital system. Only M1 LVOs were included. Sensitivities, specificities, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the following: Rapid LVO detection, gaze deviation (GD), hyperdense sign (HDS), Tmax >6 seconds, and NIHSS at presentation. The NNR was calculated for an M1 occlusion.

Results: 559 patients were included in this study. M1 occlusion was detected in 42 (7.5%) cases. Rapid LVO detection software was found to have a sensitivity of 71%, specificity of 94%, PPV of 49%, and NPV of 92% for a M1 occlusion. When both GD and HDS were combined with Rapid LVO, the specificity and PPV increased to 100% for a M1 occlusion. A negative LVO software combined with either a low (<15 mL on Tmax >6s) or high (<50 mL on Tmax >6s) Tmax threshold were found to have a specificity and PPV of 100% for no M1 occlusion. The combination of GD, HDS, Rapid LVO+ (for M1 occlusion) and Rapid LVO- with a low Tmax threshold (for no M1 occlusion) yielded 24 images NNR per 100 cases. When the combination of GD, HDS, Rapid LVO+ was combined with Rapid LVO- and a high Tmax threshold, the NNR per 100 cases was 16. With the addition of NIHSS<7 for the remaining cases in the high Tmax group, the NNR per 100 cases decreased to 9.

Conclusion: The addition of GD and HDS to the Rapid LVO increases the specificity and PPV for a M1 occlusion. When combined with a negative Rapid LVO detection and either a low or high Tmax >6s threshold, the NNR is significantly decreased. As few as 9 images per 100 would be needed to be manually reviewed by a clinician during stroke triage.

Sulfonylurea Receptor 1 in Central Nervous System Injury: An Updated Review

Sulfonylurea receptor 1 (SUR1) is a member of the adenosine triphosphate (ATP)-binding cassette (ABC) protein superfamily, encoded by Abcc8, and is recognized as a key mediator of central nervous system (CNS) cellular swelling via the transient receptor potential melastatin 4 (TRPM4) channel. Discovered approximately 20 years ago, this channel is normally absent in the CNS but is transcriptionally upregulated after CNS injury. A comprehensive review on the pathophysiology and role of SUR1 in the CNS was published in 2012. Since then, the breadth and depth of understanding of the involvement of this channel in secondary injury has undergone exponential growth: SUR1-TRPM4 inhibition has been shown to decrease cerebral edema and hemorrhage progression in multiple preclinical models as well as in early clinical studies across a range of CNS diseases including ischemic stroke, traumatic brain injury, cardiac arrest, subarachnoid hemorrhage, spinal cord injury, intracerebral hemorrhage, multiple sclerosis, encephalitis, neuromalignancies, pain, liver failure, status epilepticus, retinopathies and HIV-associated neurocognitive disorder. Given these substantial developments, combined with the timeliness of ongoing clinical trials of SUR1 inhibition, now, another decade later, we review advances pertaining to SUR1-TRPM4 pathobiology in this spectrum of CNS disease—providing an overview of the journey from patch-clamp experiments to phase III trials.

Abstract P508: Transradial Cerebral Angiography Becomes More Efficient Than Transfemoral; Lessons From 500 Consecutive Angiograms

Introduction: Transradial arterial access (TRA) for cerebral diagnostic angiography (DSA) is associated with reduced access-site complications compared with transfemoral access (TFA), though concerns about increased procedure time and radiation exposure may slow its adoption.

Objective: To examine “radial-first” cerebral angiography by measuring TRA rates of success and fluoroscopy time and comparing to TFA.

Methods: We examined 500 consecutive cerebral angiograms during the first full year of “radial-first” adoption, recording patient and procedural characteristics including intended and performed access sites, fluoroscopy time per vessel catheterized, and outcomes of the procedure.

Results: Of 500 angiograms done over a nine-month period at a single center, 431 (86.2%) of cases were successfully performed via TRA. There was one case of temporary neurologic deficit in the TRA group, and none in the TFA group (n=1, 0.2% TRA vs. n=0, 0.05 TFA, p=0.8). Vascular access-site complications were lower in the TRA group than TFA (n=2, 0.4% TRA vs. n=2, 4.7% TFA, p=0.04). There was no difference in the number of cases successfully performed via TRA in the first half of the study compared with the second (n=215, 86.0% vs. n=216, 86.4%, p=0.90). Fluoroscopy time decreased from the first half of the study to the second half for TRA performance(5.0±3.9 min/vessel vs. 3.4±3.5 min/vessel, p<0.001), while TFA performance time remained unchanged (3.7±1.8 min/vessel vs. 3.5±1.4 min/vessel, p=0.69). The median fluoroscopy time for TRA became faster than TFA after 150 angiograms.

Conclusions: Among angiograms performed during the first full year of “radial first” implementation, 86% were performed successfully using TRA. TRA efficiency continued to improve beyond the initial learning curve, exceeding that of TFA after 150 angiograms. Concerns about length of procedure or radiation exposure should not be barriers to TRA adoption.

Abstract P541: Avoiding the Radial Paradox: Radial Adoption is Not Associated With Worse Femoral Outcomes in Neuroendovascular Cases

Background and Purpose: Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence, although numerous procedures are still performed using transfemoral access (TFA). Some cardiology studies have suggested the safety benefits of TRA at a patient level may be offset at a population level by a paradoxical increase in TFA vascular access site complications (VASCs) associated with radial adoption, the so-called “radial paradox.” We studied the effect of TRA adoption on TFA performance and VASC rates in neuroendovascular procedures.

Methods: Data were collected for all neuroendovascular procedures performed over a 10-month period by trainees after implementation of a radial-first paradigm at a single center.

Results: Over the study period, 1,084 procedures were performed, including 689 (63.6%) via TRA and 395 (36.4%) via TFA. In comparison to TRA, TFA cases were performed in older patients (TFA 63 ±15 vs. TRA 56 ±16), were predominantly male (TFA 52.9% vs. TRA 38.6%), used larger sheath sizes (≥7 French, TFA 56.6% vs. TRA 2.3%), were more often emergent (TFA 37.7% vs. TRA 1.1%), and used tPA administration (TFA 15.3% vs. TRA 0%) (p<.001 for all comparisons). Overall, 29 VASCs occurred (2.7%), including 27 minor (TFA 4.6% [18/395] vs. TRA 1.3% [9/689], p=.002) and 2 major (TFA 0.3% [1/395] vs. TRA 0.1% [1/689], p>.99) complications. After multivariate analysis, independent predictors of any VASC included TFA (OR 2.8, 95% CI 1.1-7.4) and use of dual antiplatelets (OR 4.2, 95% CI 1.6—11.1).

Conclusions: TFA remains an essential route for neuroendovascular procedures, accounting for 36.4% of cases under a radial-first paradigm. TFA is disproportionately performed in patients undergoing procedures with an increased-risk for VASCs, though the minor and major VASC rates are comparable to historical controls. TFA proficiency may still be achieved in radial-first training without an increase in femoral complications.

Intrathecal transplantation of stem cells by lumbar puncture for thoracic spinal cord injury in the rat

STUDY DESIGN

Experimental investigation of intrathecal transplantation of stem cells by lumbar puncture (LP) in a rat model that simulates human thoracic spinal cord injury (SCI).

OBJECTIVES

To examine the distribution and phenotype of spinal cord-derived neural stem/progenitor cells (NSPCs) and bone marrow-derived mesenchymal stromal cells (BMSCs) following LP transplantation in SCI rats.

SETTING

Toronto Western Research Institute, Toronto, Ontario, Canada.

METHODS

NSPCs or BMSCs were transplanted via LP at level L3-5 1 week after compression SCI at T8. Rats were killed at 3, 17 and 27 days after LP transplantation and the relative distribution of cells at C4, T8 and L3-5 was quantitated. The phenotype of the NSPC and BMSC was assessed with immunocytochemistry in vitro and following LP transplantation.

RESULTS

By 4 weeks, more NSPC migrated to the lesion site relative to BMSC and uninjured animals. However, there was no preferential homing of either of these types of cells into the parenchyma of the injury site, and most of the transplanted cells remained in the intrathecal space. In vitro, spinal cord-derived NSPC proliferated and expressed nestin, but after LP transplantation, NSPC became post-mitotic and primarily expressed oligodendrocyte markers. In contrast, BMSC did not express any neural antigens in vivo.

CONCLUSION

LP is a minimally invasive method of cell transplantation that produces wide dissemination of cells in the subarachnoid space of the spinal cord. This is the first study to report and quantify the phenotype and spatial distribution of LP transplanted NSPC and BMSC in the intact and injured spinal cord.