Posttreatment Hemorrhage Research Articles

High mechanical thrombectomy procedural volume is not a reliable predictor of improved thrombectomy outcomes in patients with acute ischemic stroke in the United States.

The volume of mechanical thrombectomy (MT) performed at hospitals is used as one of the criteria for advanced-level designation for stroke care. Our study sought to determine the relationship between annual MT procedural volume and in-hospital outcomes in acute ischemic stroke patients undergoing MT in the United States. We analyzed the National Inpatient Sample from 2016 to 2020. The hospitals were grouped into quartiles based on the volume of MT procedures performed within the calendar year. We compared the rates of routine discharge/home health care; in-hospital mortality, and post-treatment intracranial hemorrhage (ICH) between the quartiles after adjusting for potential confounders. Patients undergoing MT ranged from 15,395 in quartile 1 to 78,510 MT in quartile 4. There were lower rates of discharge home/self-care of 22.5%, 20.8%, and 20.8% for quartiles 2, 3, and 4, respectively, compared with 34.9% in quartile 1. The odds of ICH increased to 1.81 (p < 0.001), 1.84 (p < 0.001), and 1.98 (p < 0.001) among the quartiles from lowest to highest procedural volumes. The odds of home discharge/self-care decreased to 0.66 (p < 0.001), 0.60 (p < 0.001), and 0.63 (p < 0.001) among the quartiles from lowest to highest procedural volumes. The odds of in-hospital mortality increased to 1.92 (p < 0.001), 1.99 (p < 0.001), and 1.84 (p < 0.001) among the quartiles from lowest to highest procedural volumes. We observed a paradoxical relationship between adverse outcomes and the annual procedural volume of MT at the hospital presumably due to the higher severity of acute ischemic stroke treated at high-volume hospitals.

Stereotactic Radiosurgery for Intracranial Cavernous Malformations: International Stereotactic Radiosurgery Society, Systematic Review, Meta-Analysis, and Practice Guidelines

The International Stereotactic Radiosurgery Society (ISRS) aims to establish evidence-based guidelines for single-fraction stereotactic radiosurgery (SRS) in treating intracranial cavernous malformations. We conducted a systematic review following PRISMA and MOOSE guidelines, searching electronic databases up to January 2024 to assess SRS's impact on post-treatment hemorrhage rates. Pooled risk ratios (RR) and confidence intervals were utilized to quantify this effect, along with assessments of lesion volume changes, seizure outcomes, and SRS-related adverse effects. Our meta-analysis included 32 studies with 2672 patients. A significant decrease in annual hemorrhage rates was observed post-treatment (RR=0.17), with rates of RR=0.29 in the first 2 years and RR=0.11 thereafter. Hemorrhage rates significantly differed before and after 2 years post-SRS (RR=0.36). Among epileptic patients, 20.2% had epilepsy pre-treatment, and 49.9% were seizure-free post-SRS, while 30.6% experienced reduced seizure frequency. Lesion volume changes showed a reduction in 46.9%, stability in 47.1%, and an increase in 6.7%. Symptomatic radiation effects affected 8% of patients. Subgroup analysis revealed symptomatic change rates of 6% at doses ≤13Gy compared to 9% at doses >13Gy. Permanent clinical deficits were rare (2%). This meta-analysis suggests SRS is an effective intervention for intracranial cavernous malformations, significantly reducing hemorrhage rates and improving seizure outcomes. ISRS practice guidelines are provided.

Treatment outcome of bridge mechanical thrombectomy with different IV-tPA dosages in the standard and extended time window in real-world practice.

Differences of treatment outcome between full or reduced dose of tissue plasminogen activator (tPA) for bridge mechanical thrombectomy (MT) in the extended time window have not been clearly established. We aimed to present real-world results of bridge MT with different tPA dosages in the standard and extended windows. Patients with anterior circulation stroke treated with MT between 2017 and 2021 at two stroke referral centers were retrospectively reviewed. Bridge MT with tPA were categorized as full (0.9mg/kg) or reduced (<0.9mg/kg) dose. Standard window (SW) cohort was defined as MT performed within 6h of acute ischemic stroke onset, while those beyond 6h as the extended window (EW) cohort. 90days Modified Rankin Scale (mRS) score, technical treatment success, in-hospital mortality, and post-treatment hemorrhage were analyzed. A total of 423 patients met the inclusion criteria, 218 of which treated in the SW, while 205 treated in the EW. Within the SW cohort, the full-dose tPA group demonstrated a higher proportion of good functional outcome (GFO) at 90days (mRS0-3) versus reduced (49% vs 21%, p = 0.0358). The overall GFO of SW was higher than that of the EW cohort (33% vs 20%, p = 0.0480). Within the EW cohort, GFO was similar between full and reduced dose groups. Successful reperfusion rate was lower in SW versus EW cohorts (39% vs 58%, p = 0.0199). In real-world practice, the GFO of bridge MT is better than MT alone. The tPA dosage is not a determining factor of GFO in EW MT.

Concurrent bacterial endocarditis is associated with worse inpatient outcomes for large vessel occlusions

BackgroundNeurological complications of bacterial endocarditis (BE) are common, including acute ischemic stroke (AIS). Although mechanical thrombectomy (MT) is effective for large vessel occlusion (LVO) stroke, data are limited on MT...

Automatic segmentation of hemorrhagic transformation on follow-up non-contrast CT after acute ischemic stroke.

Hemorrhagic transformation (HT) following reperfusion therapies is a serious complication for patients with acute ischemic stroke. Segmentation and quantification of hemorrhage provides critical insights into patients' condition and aids in prognosis. This study aims to automatically segment hemorrhagic regions on follow-up non-contrast head CT (NCCT) for stroke patients treated with endovascular thrombectomy (EVT). Patient data were collected from 10 stroke centers across two countries. We propose a semi-automated approach with adaptive thresholding methods, eliminating the need for extensive training data and reducing computational demands. We used Dice Similarity Coefficient (DSC) and Lin's Concordance Correlation Coefficient (Lin's CCC) to evaluate the performance of the algorithm. A total of 51 patients were included, with 28 Type 2 hemorrhagic infarction (HI2) cases and 23 parenchymal hematoma (PH) cases. The algorithm achieved a mean DSC of 0.66 ± 0.17. Notably, performance was superior for PH cases (mean DSC of 0.73 ± 0.14) compared to HI2 cases (mean DSC of 0.61 ± 0.18). Lin's CCC was 0.88 (95% CI 0.79-0.93), indicating a strong agreement between the algorithm's results and the ground truth. In addition, the algorithm demonstrated excellent processing time, with an average of 2.7 s for each patient case. To our knowledge, this is the first study to perform automated segmentation of post-treatment hemorrhage for acute stroke patients and evaluate the performance based on the radiological severity of HT. This rapid and effective tool has the potential to assist with predicting prognosis in stroke patients with HT after EVT.

Abstract TP123: Impact of Hospital Procedure Volume of Mechanical Thrombectomy on Outcomes in Patients With Acute Ischemic Stroke in the United States

Background: Hospitals with higher procedure volume are more likely to have lower rates of death or disability, with most neurovascular surgical and endovascular procedures. The volume of mechanical thrombectomy (MT) performed at hospitals is used as one of the criteria for advanced-level designation for stroke care. Objective: To determine the relationship between procedure volume for MT and in-hospital outcomes in acute ischemic stroke patients in the United States. Methods: We analyzed the nationally representative data from the Nationwide Inpatient Sample (NIS) from 2016 to 2020. The hospitals were grouped into quartiles based on the volume of MT procedures performed within the calendar year. We compared the rates of routine discharge/home health care (excluding those with palliative care), in-hospital mortality, and post-treatment intracranial hemorrhage (ICH) between the quartiles after adjusting for potential confounders. Results: In the logistic regression analysis, the odds of post-procedure ICH increased to 1.81 (p&lt;0.001), 1.84 (p&lt;0.001), and 1.98 (p&lt;0.001) among the quartiles from lowest to highest procedural volumes after adjusting for potential confounders including clinical severity makers. The odds of home discharge/self-care decreased to 0.66 (p&lt;0.001), 0.60 (p&lt;0.001), and 0.63 (p&lt;0.001) among the quartiles from lowest to highest procedural volumes. The odds of in-hospital mortality increased to 1.92 (p&lt;0.001), 1.99 (p&lt;0.001), and 1.84 (p&lt;0.001) among the quartiles from lowest to highest procedural volumes. Conclusions: We observed a paradoxical relationship between adverse outcomes and procedure volume of MT at the hospital, presumably due to the higher severity of acute ischemic stroke at high-volume hospitals.

Abstract 17479: Angiographic Factors Influencing Treatment Decisions in Pediatric Brain Arteriovenous Malformation (pAVM): Insights From Cart Analysis

Introduction: Pediatric cerebral AVM (pAVM) are the most common cause of hemorrhagic stroke in children. Their optimal management approach remains controversial. Determining the angiographic factors that impact outcomes for the various treatment strategies is crucial. Hypothesis: To identify angiographic factors for modality-treatment decision-making Methods: Cross-sectional study of patients diagnosed with pAVM at a pediatric stroke center between 2016 and 2021. Patients’ demographics, angiographic characteristics (volume, location, nidal aneurysms, non-plexiform rapid fistulas, venous drainage, and nidus diffuseness), treatment, and clinical outcomes were collected. Classification and Regression Tree Analysis (CART) was used to identify impactful angiographic factors, multivariate regression was applied to evaluate their significance in treatment decision-making. Results: Thirty-seven consecutive patients were included, 25 were male, with a median age of 10.3 years (IQR 7.9-13.3). Median follow-up was 30.3 months (IQR 8.6-53.8). Twenty patients presented with a ruptured pAVM. Endovascular embolization was the most common treatment (19, 51.4%), followed by radiosurgery (14, 37.8%), and observation (8, 21.6%). Twenty-seven patients (81.8%) had improved or stable functional neurologic status at last follow-up, and six (18.2%) declined (none of them by more than one point on the mRS). Only one patient had post-treatment hemorrhage during follow-up.The angiographic features associated with specific treatments were: the presence of non-plexiform rapid fistulas (endovascular in 94.0% of patients p=0.01), basal ganglia or pons location (excluded from endovascular in 86% of patients p=0.30), absence of a nidal aneurysm (radiation in 98% p=0.03). CART did not identify other potentially impactful angiographic factors. Conclusions: Our study shows generally favorable outcomes and low complication rates in pAVM patients who underwent multimodal treatment. The presence of non-plexiform rapid fistulas and nidal aneurysms should be considered when determining the appropriate treatment approach. Further prospective confirmatory analyses are warranted.

Long-term outcomes of deep pediatric arteriovenous malformations.

Multimodality treatment has been shown to be the optimal management strategy for pediatric arteriovenous malformations (AVMs). Deep AVMs represent a subset of AVMs for which optimal management may be achieved with a combination of radiosurgery and highly selective embolization, in the absence of compelling features requiring operative intervention. The objective of this study was to identify predictors of good functional outcomes in pediatric patients with deep AVMs. A retrospective cohort study of the outcomes of 79 patients with deep AVMs from January 1988 through December 2021 was performed. Deep AVMs were defined as those with the majority of the nidus centered in the basal ganglia, thalamus, or brainstem. Collected data included patient demographics and presenting symptoms, presenting modified Rankin Scale (mRS) score, radiographic findings and outcomes, management strategy, complications, and clinical outcomes as indicated by follow-up mRS score. A good outcome was defined as a follow-up mRS score ≤ 2, while a poor outcome was defined as a follow-up mRS score ≥ 3. Statistical analysis was performed to identify factors associated with functional outcomes. With a mean follow-up duration of 85.6 months, there was a 72.2% angiographic obliteration rate, with 75.9% of patients having a good clinical outcome (mRS score ≤ 2). Presenting symptoms and radiographic characteristics were not significantly associated with long-term functional outcomes. There was a significantly higher rate of posttreatment hemorrhage in patients with a poor versus good outcome (11.8% vs 0%, p = 0.010). On multivariate logistic regression analysis, poor long-term functional outcome was only associated with poor presenting mRS score (p = 0.002). Satisfactory angiographic obliteration rates and good long-term functional outcomes can be achieved for deep AVMs, with stereotactic radiosurgery as the cornerstone of multimodality treatment.

Clinical features and outcome in pediatric arteriovenous malformation: institutional multimodality treatment.

Intracranial arteriovenous-malformation (AVM) is a relatively rare condition in pediatrics, yet is a major cause of spontaneous intracranial hemorrhage with a risk of fatal hemorrhage reported to be between 4 and 29%. Little is known about vessel morphology and optimum treatment modalities including multimodality combination therapy and prognosis in children. A retrospective review of all children presenting to our institution from 2006 to 2020 that had an AVM was undertaken. A total of 50 children were identified with median age of 11 (range 1-16) years. The mean follow-up was 7.6years. Forty-one children presented as an emergency and of those, 40 had hemorrhage identified on initial brain imaging. The average nidus size was 25mm, drainage was superficial in 51% of cases, and located in eloquent cortex in 56%. The supplemental Spetzler-Martin grading indicated 78% (39/50) were grade 4 and above (moderate to high risk). Primary treatment modalities included embolization in 50% (25) or SRS in 30% (15) and surgery in 20% (10).The AVM was obliterated on follow-up DSA in 66% children. Three children had post-treatment hemorrhage, two related to embolization and one the day following SRS, giving a re-bleed rate of 6%. The GOSE was available for 32 children at long term follow and 94% had a good outcome (GOSE 5-8). Two children died due to acute hemorrhage (4%). The majority of children with AVM present with hemorrhage. The rebleed rate during definitive treatment is low at 6% over the study period. The selective use of the 3 modalities of treatment has significantly reduced mortality and severe disability.

Letter: Stereotactic Radiosurgery for Dural Arteriovenous Fistulas: A Systematic Review and Meta-Analysis and International Stereotactic Radiosurgery Society Practice Guidelines.

To the Editor: We read with interest the article by Singh et al1 synthesizing the modern literature around the use of stereotactic radiosurgery (SRS) in the treatment of cranial dural arteriovenous fistulas (DAVFs). Neurointervention has disrupted the established treatment paradigm for many neurosurgical conditions. From intracranial aneurysms and large vessel occlusions to hydrocephalus, neuroendovascular surgery favorably altered the natural history and reduced the treatment-related morbidity of these and other disease processes. This has changed the mindset of clinicians who treat patients with cerebrovascular disease. For instance, a patient with an unruptured wide-necked aneurysm may be better served with an endovascular treatment that leaves a small neck remnant than with clip reconstruction that affords complete occlusion but requires a considerably more invasive surgical approach. Endovascular therapy has, in a generally safe and minimally invasive fashion, lowered the clinical risk of many pathologies without affording complete cure. In light of the available literature, a similar shift in mindset may be warranted regarding SRS for the treatment of cranial DAVFs. Just as SRS met with initial skepticism regarding its efficacy for vestibular schwannomas,2 neurointerventionalists and cerebrovascular surgeons have been slow to embrace its utility for DAVFs.3 In recent years, mounting evidence has emerged to support the efficacy of SRS as more than just a salvage therapy after failed endovascular embolization of DAVFs.4,5 In light of this, a recent systematic review and meta-analysis by Singh et al1 on behalf of the International Stereotactic Radiosurgery Society has summarized the DAVF SRS outcomes and provided some practice guidelines. In their analysis of 705 SRS-treated patients with DAVF in 21 studies, the authors reported complete occlusion and symptomatic cure rates of nearly 70% and 80%, respectively.1 In comparison, a recent meta-analysis of transarterial DAVF embolization using ethylene vinyl alcohol copolymer (Onyx; Medtronic Neurovascular) reported a complete occlusion rate of 82%.6 A multicenter retrospective analysis of the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database reported a complete obliteration rate of 55% after initial Onyx embolization.7 In this CONDOR study, the final obliteration rate with Onyx was less than 70%, even after all treatments. Surgical DAVF series typically report a higher obliteration rates than endovascular series, but many of these surgical cases have failed endovascular therapy, and operative morbidity and mortality rates up to 17% have been reported.3,8,9 The rates of post-SRS hemorrhage and permanent neurological deficits reported by Singh et al1 in their meta-analysis were 1.1% and 1.3%, respectively. By comparison, the risk of permanent neurological deficit after DAVF embolization was 4% in the meta-analysis by Sadeh-Gonike et al6 and 16.1% in the CONDOR database.7 In a separate analysis of unruptured high-grade DAVFs from CONDOR, post-treatment hemorrhage rates in the observation, endovascular, surgical, and SRS groups were 6.9%. 1.6%, 2.3%, and 0%, respectively.4 Although there were relatively few patients in the SRS group (n = 19), the risk of post-treatment hemorrhage seems to be similar among the various therapeutic modalities for unruptured DAVFs. DAVFs can be rewarding lesions to address for neurointerventionalists, as they provide a satisfying combination of technical skill, anatomic knowledge, and innovative approaches (ie, transvenous, direct puncture, combined surgical and endovascular). However, these cases can require hours of radiation exposure for the patient over potentially multiple embolization sessions, and there is a modest risk of DAVF recurrence even after initial angiographic cure. Based on analyses of the CONDOR database, obliteration of a low-grade DAVF after a single embolization session was achieved in <40% of cases,10 and the rate of recurrent arteriovenous shunting after angiographic cure (which required a mean of >2 embolization sessions) was 7%.11 Based on these findings, SRS may warrant consideration as a first-line treatment for unruptured DAVFs.1 If patients understand the potential risks associated with the latency period between treatment and efficacy, SRS should be discussed with unruptured patients with DAVF as a viable and reasonable alternative to embolization and surgical ligation. Definitive evidence from randomized comparative trials among the various treatment strategies for DAVFs is unlikely to be forthcoming for such a rare condition. Therefore, we will continue to rely on large multicenter databases, such as CONDOR, for our best available evidence regarding management outcomes and complications in contemporary neurovascular practice. The practice guidelines put forth by the ISRS underscore the favorable risk to benefit profile of SRS for appropriately selected DAVFs.

Radiosurgery fractionation and post-treatment hemorrhage development for intact melanoma brain metastases.

To assess, for intact melanoma brain metastases (MBM), whether single-fraction stereotactic radiosurgery (SRS) versus fractionated stereotactic radiotherapy (fSRT) is associated with a differential risk of post-treatment lesion hemorrhage (HA) development. A single institution retrospective database review identified consecutive patients with previously unresected MBM treated with robotic SRS/fSRT between 2013 and 2021. The presence of lesion HA was determined by multi-disciplinary imaging review. Dosimetric variables were reported as biologically effective doses using an α/β ratio of 2.5 (BED2.5). Statistical analysis was performed using mixed effect logistic regression for post-treatment HA and Cox frailty modeling for local control (LC). The cohort included 48 patients with 226 intact MBM treated with SRS/fSRT. Of lesions without prior HA, 63 of 133 lesions (47.4%) receiving SRS demonstrated evidence of post-treatment HA versus 2 of 24 lesions (8.3%) treated with fSRT (p = 0.01). A larger maximum BED2.5 was observed in lesions developing HA compared to no HA (238.3Gy vs. 211.4Gy; p = 0.022). 12-month LC was 65.7% (95% CI 37.2-87.3%) and 77.5% (95% CI 58.5-91.2%) for lesions demonstrating pre-treatment and post-treatment HA, respectively, with no local failure events observed within 12months for non-hemorrhagic lesions (p < 0.001). We found an increased incidence of post-treatment HA for intact MBM receiving a larger maximum BED2.5, which was significantly higher for single fraction treatments within our cohort. The presence of lesion HA, either pre- or post-treatment, was indicative of inferior LC. Further investigations of optimal dose and fractionation schedules for treatment of MBM in the era of immunotherapy are warranted.

Single-Fraction vs. Fractionated Radiosurgery and the Development of Post-Treatment Hemorrhage for Intact Melanoma Brain Metastases

<h3>Purpose/Objective(s)</h3> To assess whether intracranial stereotactic radiotherapy fractionation is associated with increased risk of post-treatment lesional hemorrhage in patients with intact melanoma brain metastases (MBM). <h3>Materials/Methods</h3> A single institution retrospective review was performed of patients with previously unresected MBM treated with robotic SRS/fSRT between 2013 to 2021. The presence of lesional hemorrhage was determined by multi-disciplinary neuroradiology review of magnetic resonance imaging (MRI). Dosimetric variables were reported as biologically effective doses using an estimated α/β ratio of 2.5 (BED_2.5) for melanoma to permit comparison across varying fractionation schedules. The effect of fractionation and additional prognostic factors on the rate of post-treatment development of hemorrhage was statistically analyzed using logistic regression with random effects to account for interactions between lesions of the same patient. A Cox model was used for local control (LC) with a frailty term to account for dependence between lesions. <h3>Results</h3> The cohort included 48 patients with 226 intact MBM treated with SRS/fSRT. Evidence of hemorrhage prior to treatment was demonstrated in 69 of 226 metastases (30.5%). For lesions without signs of prior hemorrhage, 65 of 157 (41.4%) demonstrated evidence of hemorrhage after radiosurgical treatment. 63 of 133 lesions (47.4%) receiving single-fraction SRS demonstrated evidence of post-treatment hemorrhage versus 2 of 24 lesions (8.3%) treated with fSRT (<i>p=0.01</i>). Treatment factors including lesion size, prescription isodose line, as well as receipt of corticosteroids, targeted, or immune therapy were not predictive of hemorrhage occurrence. A larger maximum BED_2.5 was observed in lesions developing hemorrhage compared to no hemorrhage (mean 238.3 Gy vs. 211.4 Gy; <i>p=0.022</i>). LC at twelve-months was 65.7% (95% CI 37.2-87.3%) and 77.5% (95% CI 58.5-91.2%) for lesions demonstrating pre-treatment and post-treatment hemorrhage, respectively, with no local failure events observed in non-hemorrhagic lesions (<i>p=<0.001</i>). <h3>Conclusion</h3> Intact MBM without prior evidence of hemorrhage receiving single-fraction SRS were associated with an increased incidence of post-treatment hemorrhage when compared to those treated with fractionated stereotactic radiotherapy. The presence of lesion hemorrhage, either pre- or post-treatment, was associated with inferior local control. Post-treatment hemorrhage was correlated with a larger maximum BED_2.5. Further investigations of the clinical impact of lesional hemorrhage, factors influencing lesion control, as well as optimal dose and fractionation schedules for treatment of MBM in the era of immunotherapy are warranted.

Risk for Hemorrhage the First 2 Years After Gamma Knife Surgery for Arteriovenous Malformations: An Update.

Knowledge about the natural course of brain arteriovenous malformations (AVMs) have increased during the past 20 years, as has the number of AVMs treated, especially larger ones. It is thus timely to again analyze the risk for hemorrhage after Gamma Knife Surgery (GKS). To confirm or contradict conclusions drawn 20 years ago regarding factors that affect the risk for post-GKS hemorrhage. The outcome after GKS was studied in 5037 AVM patients followed for up to 2 years. The relation between post-treatment hemorrhage rate and a number of patient, AVM, and treatment parameters was analyzed. The results were also compared with the results from our earlier study. The annual post-treatment hemorrhage rate was 2.4% the first 2 years after GKS. Large size, low treatment dose, and old age were independent risk factors for AVM hemorrhage. After having compensated for the factors above, peripheral AVM location and female sex, at least during their child bearing ages, were factors associated with a lower post-GKS hemorrhage rate. Large AVMs (>5 cm 3 ) treated with low doses (≤16 Gy) had higher and small AVMs treated with high doses a lower risk for hemorrhage as compared with untreated AVMs. This was detectable within the first 6 months after GKS. No difference in hemorrhage rate could be detected for the other AVMs. Based on our findings, it is advisable to prescribe >16 Gy to larger AVMs, assuming that the risk for radiation-induced complications can be kept at an acceptable level.

Cerebral Venous Sinus Thrombosis in Preterm Infants.

Neonatal cerebral venous sinus thrombosis (CVST) can lead to brain injury and neurodevelopmental impairments. Previous studies of neonatal CVST have focused on term infants, and studies of preterm infants are lacking. In this study, we examined the clinical and radiological features, treatment and outcome of CVST in preterm infants. This was a retrospective, consecutive cohort study of preterm infants (gestational age <37 weeks) with radiologically confirmed CVST. All magnetic resonance imaging/MRV and CT/CTV scans were re-reviewed to study thrombus characteristics and pattern of brain injury. Outcome was assessed by the validated pediatric stroke outcome measure at the most recent clinic visit. Twenty-six preterm infants with CVST were studied. Of these, 65% were moderate-late preterm (32-37 weeks), 27% very preterm (28-32 weeks), and 8% extreme preterm (<28 weeks). Most (73%) were symptomatic at presentation with seizures or abnormal exam. Transverse (85%) and superior sagittal (42%) sinuses were common sites of thrombosis. Parenchymal brain injury was predominantly periventricular (35%) and deep white matter (31%) in location. Intraventricular hemorrhage occurred in 46%. Most infants (69%) were treated with anticoagulation. No treated infant (including eleven with pretreatment hemorrhage) had new or worsening post-treatment hemorrhage. Outcomes ranged from no deficits (50%), mild-moderate (25%), and severe (25%) impairment. In our sample of preterm infants with CVST, more than one-quarter were asymptomatic. White matter brain lesions predominated and one-half had neurological deficits at follow-up. Anticoagulation of preterm CVST in this small cohort appeared to be safe. Larger studies of preterm CVST are needed.

Is malignant edema and hemorrhage after occlusion of high-flow arteriovenous malformation related to the size of feeding arteries and draining veins?

ObjectiveOur study aimed to identify predictive factors for malignant post-treatment edema and hemorrhage in patients who underwent microsurgical treatment of arteriovenous malformation (AVM) in our institution. MethodsThe study included 72 patients treated by microsurgery for cerebral symptomatic and/or ruptured AVM between 2010 and 2020. Six patients developed postprocedural malignant edema and hemorrhage (group M); the other 66 patients had no malignant edema and hemorrhage (group NM). In each patient, flow was assessed indirectly by summing the diameters of all feeding arteries to obtain an overall diameter (ODA), and similarly for draining veins (ODV). High-flow was defined as a delay between feeding artery injection and draining vein injection (DAV)<1 second on dynamic digital subtraction angiography. Univariate analysis was performed. ResultsMean ODA and ODV were respectively 11mm (±8.2) and 11mm (±5.3) in group M and 2.9mm (±1.4) and 3.7mm (±1.3) in group NM (P=0.001). High-flow AVM was demonstrated in 4 out of 5 patients (85%) in group M and in 14 out of 55 (25%) in group NM (P=0.02). Associated aneurysm was seen in 5 patients in group M (83%) and in 11 in group NM (17%) (P=0.001). ConclusionHigh-flow AVM may be associated with higher risk of postoperative edema and hemorrhage. Multidisciplinary discussion is mandatory in these cases, to define a pre-therapeutic plan for progressive staged vascular malformation occlusion.

Seizure Rates After Stereotactic Radiosurgery for Cerebral AVMs: A Single Center Study

Seizure control after stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) is an area of growing interest, with previous studies reporting up to 70% seizure freedom after treatment. The goals of this study were to identify specific patient and AVM characteristics associated with seizure presentation and seizure outcomes after SRS treatment. A retrospective review of consecutive patients undergoing SRS for brain AVMs between 2009 and 2019 at our institution was conducted. Chi-squared and logistic regression analyses were utilized to identify patient and AVM factors associated with preoperative seizure presentation and development of new onset seizures after SRS. Two hundred ten consecutive patients presenting with AVMs treated with SRS were reviewed. Factors associated with seizure presentation included larger AVM size (P= 0.02), superficial venous drainage (P< 0.05), and parietal location (P= 0.04). Of 188 patients with follow-up (90%), 30 patients presented with seizures and 14 (47%) were seizure-free post-SRS. Of 158 patients presenting without seizure, 29 (18%) developed de novo seizures during follow-up. De novo post-SRS seizures were associated with prior craniotomy for resection of AVM (P= 0.04), post-treatment hemorrhage (P= 0.02), parietal location (P= 0.05), adverse effect requiring steroids (P < 0.01), and adverse effect requiring surgery (P < 0.01). Seizures are a common presentation of brain AVMs and can be treated effectively with SRS. However, seizures can also be a complication of SRS and are associated with post-treatment hemorrhage, edema, and need for future open surgery.

Two-Fraction Proton Beam Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations

Stereotactic radiosurgery (SRS) is a well-established treatment option that can obliterate cerebral arteriovenous malformations (AVMs). However, larger AVMs are more challenging to manage, with lower rates of obliteration and higher risk of complications. In this study, we report the obliteration rate and associated adverse effects of planned two-fraction proton SRS (PSRS) used to treat patients with larger AVMs that were deemed inoperable.A retrospective analysis including 75 patients with cerebral AVMs who received two-fraction PSRS at our institution between 1991 and 2019 was conducted. The median AVM nidus volume was 21.5 cc (range 1.4-58.1 cc). AVMs were located in critical/deep locations (basal ganglia, thalamus, or brainstem) in 21.3%. The median total dose for PSRS was 16 Gy(RBE) delivered in two fractions at a median of 7 days apart (range 1-82 days). Factors associated with obliteration and hemorrhage were assessed via univariable and multivariable analyses.Median follow up was 90 months (range 0.9-223.4 months). Total (8 patients, 11%) or partial (28 patients, 37%) obliteration was achieved among 48% of AVMs at a median time of 85.4 months (range 12.2-222.7 months). Five-year cumulative incidence of total obliteration was 29%. Five-year cumulative incidence of hemorrhage post-PSRS was 33%. Lesions with higher AVM scores were more likely to hemorrhage (P = 0.042). The most common adverse effect was Grade 1 headache acutely (11%) and long-term (9%). One patient developed a Grade 2 generalized seizure disorder.Planned two-fraction PSRS may be an effective and safe treatment option for achieving obliteration in patients with larger cerebral AVMs that are inoperable. Post-treatment hemorrhage remains a potential adverse event.D.W. Kim: None. G. Lee: None. P.H. Chapman: None. M.R. Bussiere: Consultant; American College of Radiology. J. Daartz: None. J.S. Loeffler: None. H.A. Shih: Employee; Dartmouth Hitchcock. Research Grant; AbbVie, NIH. Honoraria; UpToDate. Consultant; Cleveland Clinic. Speaker's Bureau; prIME Oncology. advisory; The Radiosurgery Society. director of clinical operations; Massachusetts General Hospital. clinical operational leader; Massachusetts General Hospital.

Effect of Prior Embolization on Outcomes After Stereotactic Radiosurgery for Pediatric Brain Arteriovenous Malformations: An International Multicenter Study.

Pediatric brain arteriovenous malformations (AVMs) are a significant cause of morbidity but the role of multimodal therapy in the treatment of these lesions is not well understood. To compare the outcomes of stereotactic radiosurgery (SRS) with and without prior embolization for pediatric AVMs. We retrospectively evaluated the International Radiosurgery Research Foundation pediatric AVM database. AVMs were categorized, based on use of pre-embolization (E+SRS)or lack thereof (SRS-only). Outcomes were compared in unadjusted and inverse probability weight (IPW)-adjusted models. Favorable outcome was defined as obliteration without post-SRS hemorrhage or permanent radiation-induced changes (RIC). The E+SRS and SRS-only cohorts comprised 91 and 448 patients, respectively. In unadjusted models, the SRS-only cohort had higher rates of obliteration (68.5%vs 43.3%, <.001) and favorable outcome (61.2%vs 36.3%, P<.001) but a lower rate of symptomatic RIC (9.0%vs 16.7%, P=.031). The IPW-adjusted rates of every outcome were similar between the 2 cohorts. However, cumulative obliteration rates at 3, 5, 8, and 10 yr remained higher in the absence of prior embolization (46.3%, 64.6%, 72.6%, and 77.4% for SRS-only vs 24.4%, 37.2%, 44.1%, and 48.7% for E+SRS cohorts, respectively; SHR=0.449 [0.238-0.846], P=.013). Embolization appears to decrease cumulative obliteration rates after SRS for pediatric AVMs without affecting the risk of post-treatment hemorrhage or adverse radiation effects arguingagainst the routine use of pre-SRS embolization. While endovascular therapy can be considered for occlusion of high-risk angioarchitectural features prior toSRS, future studies are necessary to clarify its role.

Early recurrent ischemic events after mechanical thrombectomy: effect of post-treatment intracranial hemorrhage.

Patients with intracranial hemorrhages (ICH) after mechanical thrombectomy (MT) may have a higher risk of early recurrent embolism (ERE) because of delayed initiation of anticoagulants. We assessed the rate of ischemic events in the early period after MT and the association with post-MT ICH. Patients who underwent MT in our institute were retrospectively reviewed. ERE was defined as recurrent ischemic stroke and systemic embolism within 14days after MT. The association between ERE and parenchymal hematoma (PH) was assessed. Multivariable regression analysis and inverse probability of treatment weighting was used to adjust for differences in baseline characteristics between patients with and without PH. A total of 307 patients (median age, 78years; female, 47%; median baseline National Institutes of Health Stroke Scale score, 19) were included. ERE was observed in 12 of 307 patients (8 strokes, 4 systemic embolisms; 3.9%). Median time from MT to ERE was 6.5days (IQR, 3-8days). PH occurred in 21 patients (6.8%). Median time from MT to initiating oral anticoagulants was longer in patients with PH (8days) than in those without (3days) (p < 0.01). In both unweighted and weighted multivariable analysis, PH was significantly associated with an increased risk of ERE (unweighted odds ratio, 10.60; 95% CI, 2.66-42.23; weighted odds ratio, 12.34; 95% CI, 2.49-61.07). ERE occurred in about 4% of patients after MT. PH after MT was associated with delayed initiation of oral anticoagulants and an increased risk of recurrent ischemic events. URL: https://www.clinicaltrials.gov . Unique identifier: NCT02251665.

Five-year results of randomized bioactive versus bare metal coils in the treatment of intracranial aneurysms: the Matrix and Platinum Science (MAPS) Trial

BackgroundNo randomized trial of intracranial aneurysm coiling has compared long-term efficacy of polymer-modified coils to bare metal coils (BMCs). We report 5-year results comparing Matrix2 coils to BMCs. The primary...