Anticoagulation Use and Endovascular Thrombectomy in Patients with Large Core Stroke: A Secondary Analysis of the SELECT2 Trial.

Endovascular thrombectomy (EVT) safety and efficacy in patients with large core infarcts receiving oral anticoagulants (OAC) are unknown. In the SELECT2 trial (NCT03876457), 29 of 180 (16%; vitamin K antagonists 15, direct OACs 14) EVT, and 18 of 172 (10%; vitamin K antagonists 3, direct OACs 15) medical management (MM) patients reported OAC use at baseline. EVT was not associated with better clinical outcomes in the OAC group (EVT 6 [4-6] vs MM 5 [4-6], adjusted generalized odds ratio 0.89 [0.53-1.50]), but demonstrated significantly better outcomes in patients without OAC (EVT 4 [3-6] vs MM 5 [4-6], adjusted generalized odds ratio 1.87 [1.45-2.40], p = 0.02). The OAC group had higher comorbidities, including atrial fibrillation (70% vs 17%), congestive heart failure (28% vs 10%), and hypertension (87% vs 72%), suggesting increased frailty. However, the results were consistent after adjustment for these comorbidities, and was similar regardless of the type of OACs used. Whereas any hemorrhage rates were higher in the OAC group receiving EVT (86% in OAC vs 70% in no OAC), no parenchymal hemorrhage or symptomatic intracranial hemorrhage were observed with OAC use in both the EVT and MM arms. Although we did not find evidence that the effect was due to excess hemorrhage or confounded by underlying cardiac disease or older age, OAC use alone should not exclude patients from receiving EVT. Baseline comorbidities and ischemic injury extent should be considered while making individualized treatment decisions. ANN NEUROL 2024.

Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial.

BACKGROUND: The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized. METHODS: SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined. RESULTS: Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77). CONCLUSIONS: ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

Endovascular Thrombectomy Treatment Effect in Direct vs Transferred Patients With Large Ischemic Strokes: A Prespecified Analysis of the SELECT2 Trial.

Importance: Patients with large ischemic core stroke have poor clinical outcomes and are frequently not considered for interfacility transfer for endovascular thrombectomy (EVT). Objective: To assess EVT treatment effects in transferred vs directly presenting patients and to evaluate the association between transfer times and neuroimaging changes with EVT clinical outcomes. Design, Setting, and Participants: This prespecified secondary analysis of the SELECT2 trial, which evaluated EVT vs medical management (MM) in patients with large ischemic stroke, evaluated adults aged 18 to 85 years with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) as well as an Alberta Stroke Program Early CT Score (ASPECTS) of 3 to 5, core of 50 mL or greater on imaging, or both. Patients were enrolled between October 2019 and September 2022 from 31 EVT-capable centers in the US, Canada, Europe, Australia, and New Zealand. Data were analyzed from August 2023 to January 2024. Interventions: EVT vs MM. Main Outcomes and Measures: Functional outcome, defined as modified Rankin Scale (mRS) score at 90 days with blinded adjudication. Results: A total of 958 patients were screened and 606 patients were excluded. Of 352 enrolled patients, 145 (41.2%) were female, and the median (IQR) age was 66.5 (58-75) years. A total of 211 patients (59.9%) were transfers, while 141 (40.1%) presented directly. The median (IQR) transfer time was 178 (136-230) minutes. The median (IQR) ASPECTS decreased from the referring hospital (5 [4-7]) to an EVT-capable center (4 [3-5]). Thrombectomy treatment effect was observed in both directly presenting patients (adjusted generalized odds ratio [OR], 2.01; 95% CI, 1.42-2.86) and transferred patients (adjusted generalized OR, 1.50; 95% CI, 1.11-2.03) without heterogeneity (P for interaction = .14). Treatment effect point estimates favored EVT among 82 transferred patients with a referral hospital ASPECTS of 5 or less (44 received EVT; adjusted generalized OR, 1.52; 95% CI, 0.89-2.58). ASPECTS loss was associated with numerically worse EVT outcomes (adjusted generalized OR per 1-ASPECTS point loss, 0.89; 95% CI, 0.77-1.02). EVT treatment effect estimates were lower in patients with transfer times of 3 hours or more (adjusted generalized OR, 1.15; 95% CI, 0.73-1.80). Conclusions and Relevance: Both directly presenting and transferred patients with large ischemic stroke in the SELECT2 trial benefited from EVT, including those with low ASPECTS at referring hospitals. However, the association of EVT with better functional outcomes was numerically better in patients presenting directly to EVT-capable centers. Prolonged transfer times and evolution of ischemic change were associated with worse EVT outcomes. These findings emphasize the need for rapid identification of patients suitable for transfer and expedited transport. Trial Registration: ClinicalTrials.gov Identifier: NCT03876457.

Endovascular Thrombectomy for Large Ischemic Stroke Across Ischemic Injury and Penumbra Profiles.

Importance: Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain. Objective: To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect. Design, Setting, and Participants: An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022. Intervention: EVT vs MM. Main Outcomes and Measures: Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI. Results: Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled. Conclusion and Relevance: In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased. Trial Registration: ClinicalTrials.gov Identifier: NCT03876457.

Factors Affecting Selection of TraineE for Neurointervention (FASTEN).

BACKGROUND AND IMPORTANCE: Neurointervention is a very competitive specialty in the United States due to the limited number of training spots and the larger pool of applicants. The training standards are continuously updated to ensure solid training experiences. Factors affecting candidate(s) selection have not been fully established yet. Our study aims to investigate the factors influencing the selection process. METHODS: A 52-question survey was distributed to 93 program directors (PDs). The survey consisted of six categories: (a) Program characteristics, (b) Candidate demographics, (c) Educational credentials, (d) Personal traits, (e) Research and extracurricular activities, and (f) Overall final set of characteristics. The response rate was 59.1%. As per the programs' characteristics, neurosurgery was the most involved specialty in running the training programs (69%). Regarding demographics, the need for visa sponsorship held the greatest prominence with a mean score of 5.9 [standard deviation (SD) 2.9]. For the educational credentials, being a graduate from a neurosurgical residency and the institution where the candidate's residency training is/was scored the highest [5.4 (SD = 2.9), 5.4 (SD = 2.5), respectively]. Regarding the personal traits, assessment by faculty members achieved the highest score [8.9 (SD = 1)]. In terms of research/extracurricular activities, fluency in English had the highest score [7.2 (SD = 1.9)] followed by peer-reviewed/PubMed-indexed publications [6.4 (SD = 2.2)]. CONCLUSION: Our survey investigated the factors influencing the final decision when choosing the future neurointerventional trainee, including demographic, educational, research, and extracurricular activities, which might serve as valuable guidance for both applicants and programs to refine the selection process.

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial.

BACKGROUND: Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients. METHODS: SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed. FINDINGS: The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]). INTERPRETATION: In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up. FUNDING: Stryker Neurovascular.

Trial of Endovascular Thrombectomy for Large Ischemic Strokes.

BACKGROUND: Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations. METHODS: We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome. RESULTS: The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group. CONCLUSIONS: Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Understanding the genetics of intracranial aneurysms: A primer.

The genetics of intracranial aneurysms is complex. Much work has been done looking at the extracellular matrix surrounding cerebral vasculature as well as the role of matrix metalloproteinases. This comprehensive review summarizes what is known to date about the important genetic components that predispose to aneurysm formation and critically discusses the published findings. We discuss promising pre-clinical models of aneurysm formation and subarachnoid hemorrhage, and highlight avenues for future discovery, while considering limitations in the research to date. This review will further serve as a comprehensive reference guide to understand the genetic underpinnings for aneurysm pathophysiology and act as a primer for further investigation.

Force and aspiration on catheters utilized in the ADAPT technique in acute ischemic stroke: A bench top analysis.

INTRODUCTION: Given the high morbidity and mortality of stroke, there remains a demand for techniques that provide rapid and safe intervention while improving time to recanalization. The direct aspiration first pass technique (ADAPT) uses force and aspiration for clot removal without the aid of separators or retrievers. In this study, we compare the force and aspiration qualities of commercially available catheters. METHODS: Four different catheters with varying inner diameters were set up in a bench top model to test catheter tip pressure and flow rate. Catheter tip pressure was measured by attaching the catheter to a vacuum pressure gauge and an aspiration pump. The flow rate was calculated by measuring the volume of room temperature water aspirated through each catheter over a given time. RESULTS: The Microvention Sofia catheter generated the greatest tip force (21.32 g), and the Stryker AXS Catalyst 6 catheter generated the smallest tip force (15.88 g). The Penumbra ACE 068 catheter and Medtronic ARC catheter measured 20.87 g and 16.78 g respectively. The ACE 068 had highest rate of aspiration at 289 mL/min, and the Catalyst 6 catheter had the lowest rate at 214. The Microvention Sofia catheter had the second highest rate while the ARC had the third highest rate, measuring 285 mL/min and 256 mL/min, respectively. CONCLUSIONS: When using the ADAPT technique, knowledge of the tip force and catheter flow rate of newer catheters with larger distal inner diameters may guide selection of aspiration catheters. While this study demonstrates differences in tip force and flow rate of different commercially available catheters, clinical translation will require further testing and evaluation.

Treatment of a rare and complex carotid-cavernous fistula.

Carotid-cavernous fistulas (CCFs) are abnormal connections between arteries and the cavernous sinuses. Traditionally, the Barrow Classification system has been used to characterise these fistulas based on their arterial supply from the internal carotid artery (ICA), external carotid artery (ECA) or both. We present a unique case of a patient with a complex CCF with arterial feeders from dural branches of the ECA, ICA and vertebral artery (VA), which, to our knowledge, has not been reported in the literature. Given unique arterial supply pattern involving contribution from the extracranial VA, this CCF falls outside of the traditional Barrow Classification system. The patient ultimately underwent a transfemoral transvenous coil embolisation using multiple dynamic venous routes with obliteration of bilateral CCFs and near complete resolution of her preoperative symptoms.

Analysis: Intravascular Devices with a Higher Risk of Polymer Emboli: The Need for Particulate Generation Testing.

Hydrophilic polymer coatings on intravascular devices lower friction between the device and vasculature, thereby reducing trauma during interventional procedures. Polymer coating embolism-the detachment and downstream embolism of polymer particles-has been reported as an iatrogenic complication of coated interventional devices affecting the vasculature and various organs. The Food and Drug Administration (FDA) acknowledges this complication and continues to work with stakeholders to close gaps in performance testing and standards related to polymer coating integrity. Recent innovations within interventional technologies have led to development of new hydrophilic-coated devices with expanded indications for use. The 2018 FDA draft guidance for intravascular guidewires expands the application of particulate generation testing to most devices and recommends labeling changes to increase industry awareness. This article highlights current procedural trends where the phenomenon of polymer coating embolism may be more prevalent. It describes the mechanisms of polymer separation, reported clinical sequelae, and risk factors for relevant indications. These procedural trends and associated risk factors articulate the need for particulate testing and support the FDA's draft guidance recommendations for performance testing of applied coatings. If standardized, particulate assessments may allow characterization and comparisons of coating integrity among devices from various manufacturers, and are an important foundation for setting particulate limits. As hydrophilic coatings enable endovascular treatment for a range of patient populations, setting particulate limits or finding alternative solutions without compromise to device function may be essential. Particulate testing is relevant to physicians, regulators, and manufacturers for the purposes of product development and quality improvement of interventional devices.

Intraventricular thrombolysis after endovascular treatment of a ruptured arteriovenous malformation.

Intraventricular haemorrhage (IVH) secondary to arteriovenous malformation (AVM) rupture carries significant morbidity and mortality. External ventricular drainage of IVH is frequently complicated by thrombus formation within the ventricular catheter and therefore often unsuccessful at treating hydrocephalus in this setting. Intraventricular administration of recombinant tissue-type plasminogen activator (rtPA) has proved successful in the treatment of spontaneous panventricular haemorrhage. However, usage of rtPA is contraindicated in the setting of a ruptured AVM or aneurysm in which the bleeding source has not been secured. There are only a few reports of intraventricular thrombolysis in the treatment of IVH from AVM rupture. We present the case of successful application of rtPA to treat IVH after endovascularly securing the haemorrhage site of the AVM. Intraventricular thrombolysis remains an option for the treatment of IVH in the setting of AVM rupture and should be considered on a case-by-case basis.

Intraventricular thrombolysis after endovascular treatment of a ruptured arteriovenous malformation.

Intraventricular haemorrhage (IVH) secondary to arteriovenous malformation (AVM) rupture carries significant morbidity and mortality. External ventricular drainage of IVH is frequently complicated by thrombus formation within the ventricular catheter and therefore often unsuccessful at treating hydrocephalus in this setting. Intraventricular administration of recombinant tissue-type plasminogen activator (rtPA) has proved successful in the treatment of spontaneous panventricular haemorrhage. However, usage of rtPA is contraindicated in the setting of a ruptured AVM or aneurysm in which the bleeding source has not been secured. There are only a few reports of intraventricular thrombolysis in the treatment of IVH from AVM rupture. We present the case of successful application of rtPA to treat IVH after endovascularly securing the haemorrhage site of the AVM. Intraventricular thrombolysis remains an option for the treatment of IVH in the setting of AVM rupture and should be considered on a case-by-case basis.

Force and aspiration analysis of the ADAPT technique in acute ischemic stroke treatment.

INTRODUCTION: The development of new revascularization devices has significantly improved recanalization rates and time to reperfusion. A direct aspiration first-pass (ADAPT) technique for stroke thrombectomy was recently shown to be an effective and rapid way to achieve revascularization. The technique focuses on engaging and removing a clot without the use of a separator or retriever by relying on the force and aspiration generated by the catheter. We sought to compare the physical and fluid dynamic properties (force and aspiration) of commercially available catheters to determine the most effective catheter for the ADAPT technique. METHODS: Benchtop models were employed to compare aspiration for each catheter by submersing the catheter into a graduated cylinder and aspirating water. The volume of fluid aspirated and flow rates were calculated. Force of aspiration at the tip of each catheter was measured using a vacuum pressure gauge while the catheter was attached to a standard aspiration pump. Force was then calculated. RESULTS: The Penumbra 5MAX ACE catheter had the greatest aspiration rate of all the catheters at 245 mL/min. The Penumbra 5 MAX catheter aspirated 212 mL/min, followed by the Navien 058 and DAC 057 with 198 mL/min and 197 mL/min, respectively. The Penumbra 5MAX ACE generated the greatest tip force (18.25 g) and the 5MAX had the least amount of force (14.77 g). CONCLUSIONS: The physical and fluid dynamic properties of currently available catheters suggest that the 5MAX ACE is the optimal catheter to use in direct aspiration for stroke therapy.

The impact of early flow and brain oxygen crisis on the outcome of patients with severe traumatic brain injury.

BACKGROUND: Multimodality monitoring and goal-directed therapy may not prevent blood flow and brain oxygen (Flow/BrOx) crisis. We sought to determine the impact of these events on outcome in patients with severe traumatic brain injury (sTBI). METHODS: Twenty-four patients with sTBI were treated to maintain intracranial pressure (ICP) less than or equal to 20 mm Hg, cerebral perfusion pressure (CPP) greater than or equal to 60 mm Hg, brain oxygen greater than or equal to 20 mm Hg, and near infrared spectroscopy greater than or equal to 60%. Flow/BrOx crisis events were recorded. The 14-day predicted mortality was compared with actual mortality. RESULTS: Nonsurvivors had a significantly higher number of crisis events nonresponsive to treatment (P < .05). Mortality was 87.5% in patients with greater than or equal to 20 events versus 6.3% in patients with less than 20 events. The predicted mortality was 58%, whereas actual mortality was 33.3% (8/24), yielding a 42% reduction in mortality. CONCLUSIONS: A multimodality monitoring and goal-directed therapy may decrease mortality in sTBI. However, Flow/BrOx crisis events still occur and predict a poor outcome.

Symptomatic de novo arteriovenous malformation in an adult: Case report and review of the literature.

BACKGROUND: Cerebral arteriovenous malformations (AVMs) have been long thought to be a congenital anomaly of vasculogenesis in which arteries and veins form direct connections forming a vascular nidus without an intervening capillary bed or neural tissue. Scattered case reports have described that AVMs may form de novo suggesting they can become an acquired lesion. CASE DESCRIPTION: The current case report describes a patient who presented with new-onset seizures with an initial negative magnetic resonance imaging (MRI) of the brain and subsequently developed an AVM on a MRI 9 years later. CONCLUSION: This case joins a small, but growing body of literature that challenges the notion that all AVMs are congenital.

Histopathological assessment of fatal ipsilateral intraparenchymal hemorrhages after the treatment of supraclinoid aneurysms with the Pipeline Embolization Device.

OBJECT: Delayed ipsilateral intraparenchymal hemorrhage has been observed following aneurysm treatment with the Pipeline Embolization Device (PED). The relationship of this phenomenon to the device and/or procedure remains unclear. The authors present the results of histopathological analyses of the brain sections from 3 patients in whom fatal ipsilateral intracerebral hemorrhages developed several days after uneventful PED treatment of supraclinoid aneurysms. METHODS: Microscopic analyses revealed foreign material occluding small vessels within the hemorrhagic area in all patients. Further analyses of the embolic materials using Fourier transform infrared (FTIR) spectroscopy was conducted on specimens from 2 of the 3 patients. Although microscopically identical, the quantity of material recovered from the third patient was insufficient for FTIR spectroscopy. RESULTS: FTIR spectroscopy showed that the foreign material was polyvinylpyrrolidone (PVP), a substance that is commonly used in the coatings of interventional devices. CONCLUSIONS: These findings are suggestive of a potential association between intraprocedural foreign body emboli and post-PED treatment-delayed ipsilateral intraparenchymal hemorrhage.

Modern endovascular treatments of occlusive pediatric acute ischemic strokes: case series and review of the literature.

PURPOSE: Literature on the endovascular treatment of occlusive acute ischemic stroke (AIS) in the pediatric population remains nebulous. Clinical trials evaluating the role of systemic and intra-arterial thrombolysis, and mechanical thrombectomy have been strictly isolated to the adult population and largely unknown in their safety and efficacy in the pediatric group. METHODS: The authors present a review of the literature and their own two cases of occlusive acute ischemic stroke in children younger than the age of 10 years who were treated with modern endovascular devices, specifically with stent retrievers, and discuss their clinical and technical considerations as well as their limitations. RESULTS: In both pediatric patients, a combination of stent retriever and Penumbra aspiration were used to achieve Thrombolysis In Cerebral Infarction (TICI) 2a or greater with reduction of overall stroke burden. A reduction of National Institutes of Health Stroke Scale (NIHSS) of 8 or greater was achieved at discharge. At 3-month follow-up, the patients had a NIHSS of 6 and 2, respectively. One patient continued to improve from NIHSS of 6 to 3 at 6 months. CONCLUSION: In carefully, selected pediatric patients, modern endovascular techniques may be used to treat occlusive pediatric AIS. However, larger clinical trials are needed to evaluate the overall safety and effectiveness.