Effectiveness of Preradiosurgical Embolization with NBCA for Arteriovenous Malformations - Retrospective Outcome Analysis in a Japanese Registry of 73 Patients (J-REAL study)

PurposeRecent reports have posed doubts about the effect of preradiosurgical embolization in brain arteriovenous malformation (AVM) because it makes the planning of stereotactic radiosurgery (SRS) difficult and has the risk of recanalization out of the target. We investigated whether the performance and quality of embolization may influence the success of SRS based on a retrospective case cohort study.Materials and MethodsSeventy-three patients who underwent embolization followed by SRS between 2003 and 2012 in eight institutes with neurointerventionists were considered. They were divided into the following two groups at 3 years of follow up after the final SRS: “successful occlusion group” (S group), with radiologically complete occlusion of AVM; and “non-successful occlusion group” (N group) with persistent remnant nidus or abnormal vascular networks. Patient background, AVM profile, embolization performance grade and complications were compared in each group. The quality of embolization was evaluated with the new grading system: embolization performance grade (E grade), specializing the achievement of nidus embolization. E grade A was defined as sufficient nidus embolization with more than half of the total number of feeders achieving nidus penetration. E grade B was defined as less than half achievement of nidus embolization, and E grade C was defines as failure to perform nidus embolization.ResultsForty-three patients were included in the S group, and 29 patients were included in the N group. The size and Spetzler-Martin grade of AVM and the rate of diffuse type was higher in the N group without statistical significance. The embolization performance level according to E grade indicated a significantly higher rate of successful embolization with more than 50% of nidus penetration in the S group (P<0.001). This difference was also confirmed in the subanalysis for limited cases, excluding smaller AVMs with complete occlusion with SRS alone (P=0.001).ConclusionThe cause of the unsuccessful result of post-embolization SRS might be the large, diffuse angioarchitecture, but proper embolization with a high rate of nidus penetration to avoid recanalization is more important. Effective embolization is essential to contribute to and promote the effect of radiosurgery

Perceived acceptable uncertainty regarding comparability of endovascular treatment alone versus intravenous thrombolysis plus endovascular treatment.

BACKGROUND Most trials comparing endovascular treatment (EVT) alone versus intravenous thrombolysis with alteplase (IVT) + EVT in directly admitted patients with a stroke are non-inferiority trials. However, the margin based on the level of uncertainty regarding non-inferiority of the experimental treatment that clinicians are willing to accept to incorporate EVT alone into clinical practice remains unknown. OBJECTIVE To characterize what experienced stroke clinicians would consider an acceptable level of uncertainty for hypothetical decisions on whether to administer IVT or not before EVT in patients admitted directly to EVT-capable centers. METHODS A web-based, structured survey was distributed to a cross-section of 600 academic neurologists/neurointerventionalists. For this purpose, a response framework for a hypothetical trial comparing IVT+EVT (standard of care) with EVT alone (experimental arm) was designed. In this trial, a similar proportion of patients in each arm achieved functional independence at 90 days. Invited physicians were asked at what level of certainty they would feel comfortable skipping IVT in clinical practice, considering these hypothetical trial results. RESULTS There were 180 respondents (response rate: 30%) and 165 with complete answers. The median chosen acceptable uncertainty suggesting reasonable comparability between both treatments was an absolute difference in the rate of day 90 functional independence of 3% (mode 5%, IQR 1-5%), with higher chosen margins observed in interventionalists (aOR 2.20, 95% CI 1.06 to 4.67). CONCLUSION Physicians would generally feel comfortable skipping IVT before EVT at different certainty thresholds. Most physicians would treat with EVT alone if randomized trial data suggested that the number of patients achieving functional independence at 90 days was similar between the two groups, and one could be sufficiently sure that no more than 3 out of 100 patients would not achieve functional independence at 90 days due to skipping IVT

Standards of Practice in Acute Ischemic Stroke Intervention: International Recommendations

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Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

BACKGROUND: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study\u27s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines. METHODS: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation. FINDINGS: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p\u3c0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p\u3c0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile. INTERPRETATION: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction

Abstract 1122‐000146: A Survey of Current Status and Roles of Interventional Neurologists in Japan

Introduction: In Japan, there are more board‐certified neurosurgeons than board‐certified neurologists, and a significant part of stroke practice is provided by neurosurgeons. In neuroendovascular therapy practice, the trend of neurosurgeons to be in majority is more pronounced. The most of neuroendovascular therapy specialists (n = 1,586) certified by the Japanese Society for Neuroendovascular Therapy (JSNET) consists of neurosurgeons, and the proportion of neurologists/internists is only 8% (n = 128) as of April 2021. The aim of this study is to investigate the current status and roles of interventional neurologists, the minority providing neuroendovascular therapy, in Japanese clinical setting. Methods: Between 16th and 28th February 2021, the Japan Society of Vascular and Interventional Neurology (JSVIN) conducted a survey for society‐member neurologists and internists using questionnaires on Google Forms. The questionnaires consisted of 11 items regarding years after graduation, facility location, department, work style (full‐time or concurrent interventionalist), diseases for which respondents were engaged, disease/procedure preferences which respondents would treat by themselves, respondents’ roles in their own neuroendovascular therapy team, and others. Results: Replies were obtained from 112 (67.1%) out of all JSVIN‐member neurologists and internists (n = 167). The respondents included 71 JSNET‐certified specialists and they consisted of 56.3% of all the JSNET‐certified neurologists/internists. The departments to where the respondents belonged were Neurology in 66%, Cerebrovascular medicine in 25%, Neuroendovascular therapy in 4%, and Neurosurgery in 3%. The median years after graduation was 15 years (interquartile range, 10 – 21 years) and the proportion of respondents who have graduated 10 years or less was 30%. Respondents’ facilities were distributed around 27 prefectures of all 47 Japanese prefectures and a significant proportion of those was located in urban area; 20% in Osaka and 13% in Tokyo. The number of full‐time interventionalist was only 1. Sixty‐three (56%) were concurrently engaged in general neurology practice, and 33 (30%) in stroke neurology practice. The proportions of diseases for which the respondents were engaged were ischemic cerebrovascular diseases (acute large vessel occlusion strokes, carotid stenoses, and others) in 100%, hemorrhagic cerebrovascular diseases (cerebral aneurysms, arteriovenous shunts, and others) in 44%, and other diseases (tumors, spinal vascular disorders, and others) in 28%. The proportions of disease/procedure preferences which respondents would treat by themselves were acute stroke thrombectomy in 90%, carotid/intracranial stenoses in 87%, ruptured cerebral aneurysms in 38%, unruptured cerebral aneurysms in 31%, cerebral arteriovenous shunts in 33%, brain tumors in 29%, spinal vascular disorders in 13%, and pediatric diseases in 3%. Respondents’ roles in their own neuroendovascular therapy team were diagnostic performances based on neurologist’s skills in 89%, comorbidity assessment and management based on internist’s skills in 88%, precise neurological evaluation in 77%, neurosonological evaluation in 75%, and establishments of in‐hospital workflow/multi‐disciplinary collaboration in 71%. Conclusions: Most of interventional neurologists in Japan were engaged in neuroendovascular therapy mainly for ischemic cerebrovascular diseases in parallel with general neurology and/or stroke neurology practices. Interventional neurologists’ skill set developed in neurology/internist trainings and practices might contribute to the quality improvement of neuroendovascular therapy in Japan