Prediction of delayed cerebral ischemia after cerebral aneurysm rupture using explainable machine learning approach.

BACKGROUND: Aneurysmal subarachnoid hemorrhage results in significant mortality and disability, which is worsened by the development of delayed cerebral ischemia. Tests to identify patients with delayed cerebral ischemia prospectively are of high interest. OBJECTIVE: We created a machine learning system based on clinical variables to predict delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage patients. We also determined which variables have the most impact on delayed cerebral ischemia prediction using SHapley Additive exPlanations method. METHODS: 500 aneurysmal subarachnoid hemorrhage patients were identified and 369 met inclusion criteria: 70 patients developed delayed cerebral ischemia (delayed cerebral ischemia+) and 299 did not (delayed cerebral ischemia-). The algorithm was trained based upon age, sex, hypertension (HTN), diabetes, hyperlipidemia, congestive heart failure, coronary artery disease, smoking history, family history of aneurysm, Fisher Grade, Hunt and Hess score, and external ventricular drain placement. Random Forest was selected for this project, and prediction outcome of the algorithm was delayed cerebral ischemia+. SHapley Additive exPlanations was used to visualize each feature's contribution to the model prediction. RESULTS: The Random Forest machine learning algorithm predicted delayed cerebral ischemia: accuracy 80.65% (95% CI: 72.62-88.68), area under the curve 0.780 (95% CI: 0.696-0.864), sensitivity 12.5% (95% CI: -3.7 to 28.7), specificity 94.81% (95% CI: 89.85-99.77), PPV 33.3% (95% CI: -4.39 to 71.05), and NPV 84.1% (95% CI: 76.38-91.82). SHapley Additive exPlanations value demonstrated Age, external ventricular drain placement, Fisher Grade, and Hunt and Hess score, and HTN had the highest predictive values for delayed cerebral ischemia. Lower age, absence of hypertension, higher Hunt and Hess score, higher Fisher Grade, and external ventricular drain placement increased risk of delayed cerebral ischemia. CONCLUSION: Machine learning models based upon clinical variables predict delayed cerebral ischemia with high specificity and good accuracy.

Short- and long-term outcomes of moyamoya patients post-revascularization.

OBJECTIVE: The post-bypass stroke risk factors and long-term outcomes of moyamoya patients are not well documented. Therefore, the authors studied 30-day stroke risks and patients' long-term physical, functional, and social well-being. METHODS: This was a single-institution combined moyamoya disease (MMD) database interrogation and questionnaire study. From 1991 to 2014, 1250 revascularization procedures (1118 direct bypasses, 132 indirect bypasses) were performed in 769 patients. Completed questionnaires were received from and available for analysis on 391 patients, and 6-month follow-up data were available for 96.4% (741/769) of the patients. RESULTS: The patients consisted of 548 females and 221 males, with a mean age of 32 years (range 1-69 years). Three hundred fifty-eight bypasses were performed in 205 pediatric patients (73% direct bypasses), and 892 revascularizations were performed in 564 adults (96% direct bypasses). Fifty-two patients (6.8%) developed major strokes with a worsening modified Rankin Scale (mRS) score within 30 days postoperatively. The 30-day major stroke risk was 5.3% (41/769) and 2.6% (12/467) after the first and second bypasses, respectively. Logistic regression analysis revealed that older age, modified MRI (mMRI) score, and hemodynamic reserve (HDR) score are clearly associated with higher postoperative stroke risks. Over a mean follow-up of 7.3 years (range 0.5-26 years), the long-term stroke risk among 741 patients was 0.6% per patient-year; 75% of these patients had excellent outcomes (mRS score 0-1). The long-term outcome questionnaire study showed that 84% (234/277) of patients reported resolution or improvement in their preoperative headache, 83% (325/391) remained employed or in school, and 87% (303/348) were self-caring. CONCLUSIONS: In this large, single-center surgical series, most of the adult and pediatric patients had direct revascularization, with a 4.2% per-bypass-procedure (6.8% per patient) 30-day major stroke risk and a 0.6% per-patient-year long-term stroke risk. The authors identified various risk factors that are highly correlated with postoperative morbidity (age, mMRI score, and HDR score) and are involved in ongoing work to develop the predictive modeling for future patient selection and treatment.

Corrigendum: Revisiting Stem Cell-Based Clinical Trials for Ischemic Stroke.

[This corrects the article DOI: 10.3389/fnagi.2020.575990.].

Hemorrhage risk of direct oral anticoagulants in real-world venous thromboembolism patients.

INTRODUCTION: Venous thromboembolism (VTE) management increasingly involves anticoagulation with direct oral anticoagulants (DOACs). Few studies have used competing-risks analyses to ascertain the mortality-adjusted hemorrhage and recurrent VTE (rVTE) risk of individual DOACs. Furthermore, hemorrhage risk factors in patients treated with apixaban remain underexplored. MATERIALS AND METHODS: Patients diagnosed with VTE receiving anticoagulation were identified from the Optum Clinformatics Data Mart (2003-2019). Study endpoints included readmissions for intracranial hemorrhage (ICH), non-intracranial hemorrhage (non-ICH hemorrhage), and rVTE. Coarsened exact matching was used to balance baseline clinical characteristics. Complication incidence was evaluated using a competing-risks framework. We additionally modeled hemorrhage risk in apixaban-treated patients. RESULTS: Overall, 225,559 patients were included, of whom 34,201 received apixaban and 46,007 received rivaroxaban. Compared to rivaroxaban, apixaban was associated with decreased non-ICH hemorrhage (sHR = 0.560, 95%CI = 0.423-0.741), but not ICH, and rVTE (sHR = 0.802, 95%CI = 0.651-0.988) risk. This was primarily in emergent readmissions (sHR[emergent hemorrhage] = 0.515, 95%CI = 0.372-0.711; sHR[emergent rVTE] = 0.636, 95%CI = 0.488-0.830). Contributors to emergent hemorrhage in apixaban-treated patients include older age (sHR = 1.025, 95%CI = 1.011-1.039), female sex (sHR = 1.662, 95%CI = 1.252-2.207), prior prescription antiplatelet therapy (sHR = 1.591, 95%CI = 1.130-2.241), and complicated hypertension (sHR = 1.936, 95%CI = 1.134-3.307). Patients anticipated to be "high-risk" experienced elevated ICH (sHR = 3.396, 95%CI = 1.375-8.388) and non-ICH hemorrhage (sHR = 3.683, 95%CI = 2.957-4.588) incidence. CONCLUSIONS: In patients with VTE receiving anticoagulation, apixaban was associated with reduced non-ICH hemorrhage and rVTE risk, compared to rivaroxaban. Risk reduction was restricted to emergent readmissions. We present a risk-stratification approach to predict hemorrhage in patients receiving apixaban, potentially guiding future clinical decision-making.

Intraoperative Neuromonitoring for Cerebral Arteriovenous Malformation Embolization: A Propensity-Score Matched Retrospective Database Study.

Introduction The treatment of cerebral arteriovenous malformations (AVMs) may result in neurologic morbidity, particularly when an AVM is located in or adjacent to eloquent brain regions. Intraoperative neurophysiologic monitoring (IONM) may be utilized to reduce the risk of iatrogenic injury during endovascular AVM embolization; however, IONM for endovascular AVM embolization is not ubiquitously the standard of care. Methods Admissions for AVM embolization were assessed from the IBM MarketScan® Commercial and Medicare Supplemental databases (IBM Watson Health, Somers, NY). Inclusion criterion for patients was continuous enrollment six months before and after the index encounter. The use of IONM and presence of intracranial hemorrhage (ICH) were noted. Propensity-score matched cohorts with and without IONM were generated to minimize bias between treatment groups (adjusting for age, sex, and comorbidities). Results From 2007 to 2016, there were 16,279 patients diagnosed with cerebral AVM in the MarketScan database. Embolized patients were stratified into IONM and non-IONM cohorts; there were 357 patients in the IONM cohort and 1775 patients in the non-IONM cohort. Provider types were significantly different between cohorts (p<0.005). Unruptured AVMs were significantly more likely to be embolized with adjunctive IONM (17.7%) compared to ruptured AVMs (7.9%) (p<0.005). After balancing for baseline comorbidities, there were 266 patients in the IONM cohort, and 1347 patients in the non-IONM cohort. Among unruptured AVM patients, IONM was linked to a significantly shorter length of stay (2.72 versus 4.92 days; p<0.005), significantly lower rates of complications within 30 days of discharge (0.00% versus 1.88%; p=0.038), and significantly lower total payment ($40,179 versus $50,844; p<0.0001). Conclusion Endovascular embolization for unruptured AVMs performed with adjunctive IONM was associated with shorter length of stay, lower complication rates, and hospitalization costs.

Impact of Clot Shape on Successful M1 Endovascular Reperfusion.

Objectives: The susceptibility-vessel-sign (SVS) allows thrombus visualization, length estimation and composition, and it may impact reperfusion during mechanical thrombectomy (MT). SVS can also describe thrombus shape in the occluded artery: in the straight M1-segment (S-shaped), or in an angulated/traversing a bifurcation segment (A-shaped). We determined whether SVS clot shape influenced reperfusion and outcomes after MT for proximal middle-cerebral-artery (M1) occlusions. Methods: Between May 2015 and March 2018, consecutive patients who underwent MT at one comprehensive stroke center and who had a baseline MRI with a T2* sequence were included. Clinical, procedural and radiographic data, including clot shape on SVS [angulated/bifurcation (A-SVS) vs. straight (S-SVS)] and length were assessed. Primary outcome was successful reperfusion (TICI 2b-3). Secondary outcome were MT complication rates, MT reperfusion time, and clinical outcome at 90-days. Predictors of outcome were assessed with univariate and multivariate analyses. Results: A total of 62 patients were included. 56% (35/62) had an A-SVS. Clots were significantly longer in the A-SVS group (19 mm vs. 8 mm p = 0.0002). Groups were otherwise well-matched with regard to baseline characteristics. There was a significantly lower rate of successful reperfusion in the A-SVS cohort (83%) compared to the S-SVS cohort (96%) in multivariable analysis [OR 0.04 (95% CI, 0.002-0.58), p = 0.02]. There was no significant difference in long term clinical outcome between groups. Conclusion: Clot shape as determined on T2* imaging, in patients presenting with M1 occlusion appears to be a predictor of successful reperfusion after MT. Angulated and bifurcating clots are associated with poorer rates of successful reperfusion.

Conventional versus stereotactic image guided pedicle screw placement during spinal deformity correction: a retrospective propensity score-matched study of a national longitudinal database.

PURPOSE/AIM: To compare complications, readmissions, revisions, and payments between navigated and conventional pedicle screw fixation for treatment of spine deformity. METHODS: The Thomson Reuters MarketScan national longitudinal database was used to identify patients undergoing osteotomy, posterior instrumentation, and fusion for treatment of spinal deformity with or without image-guided navigation between 2007-2016. Conventional and navigated groups were propensity-matched (1:1) to normalize differences between demographics, comorbidities, and surgical characteristics. Clinical outcomes and charges were compared between matched groups using bivariate analyses. RESULTS: A total of 4,604 patients were identified as having undergone deformity correction, of which 286 (6.2%) were navigated. Propensity-matching resulted in a total of 572 well-matched patients for subsequent analyses, of which half were navigated. Rate of mechanical instrumentation-related complications was found to be significantly lower for navigated procedures (p = 0.0371). Navigation was also associated with lower rates of 90-day unplanned readmissions (p = 0.0295), as well as 30- and 90-day postoperative revisions (30-day: p = 0.0304, 90-day: p = 0.0059). Hospital, physician, and total payments favored the conventional group for initial admission (p = 0.0481, 0.0001, 0.0019, respectively); however, when taking into account costs of readmissions, hospital payments became insignificantly different between the two groups. CONCLUSIONS: Procedures involving image-guided navigation resulted in decreased instrumentation-related complications, unplanned readmissions, and postoperative revisions, highlighting its potential utility for the treatment of spine deformity. Future advances in navigation technologies and methodologies can continue to improve clinical outcomes, decrease costs, and facilitate widespread adoption of navigation for deformity correction.

Efficacy and safety of embolization of dural arteriovenous fistulas via the ophthalmic artery.

INTRODUCTION: Dural arteriovenous fistulae (DAVF) are vascular lesions with arteriovenous shunting that may be treated with surgical obliteration or endovascular embolization. Some DAVF, such as anterior cranial fossa DAVF (AC-DAVF) derive their arterial supply from ophthalmic artery branches in nearly all cases, and trans-arterial embolization carries a risk of vision loss. We determined the efficacy and safety of trans-ophthalmic artery embolization of DAVF. MATERIALS AND METHODS: We performed a retrospective cohort study of all patients with DAVF treated by trans-ophthalmic artery embolization from 2012 to 2020. Primary outcome was angiographic cure of the DAVF. Secondary outcomes included vision loss, visual impairment, orbital cranial nerve injury, stroke, modified Rankin Scale at 90-days, and mortality. RESULTS: 12 patients met inclusion criteria (9 males; 3 females). 10 patients had AC-DAVF. Patient age was 59.7 ± 9.5 (mean ± SD) years. Patients presented with intracranial hemorrhage (4 patients), headache (4 patients), amaurosis fugax (1 patients), or were incidentally discovered (2 patients). DAVF Cognard grades were: II (1 patient), III (6 patients), and IV (5 patients). DAVF were embolized with Onyx (10 patients), nBCA glue (1 patient), and a combination of coils and Onyx (1 patient). DAVF cure was achieved in 11 patients (92%). No patients experienced vision loss, death, or permanent disability. One patient experienced a minor complication of blurry vision attributed to posterior ischemic optic neuropathy. 90-day mRS was 0 (10 patients) and 1 (2 patients). CONCLUSIONS: Trans-ophthalmic artery embolization is an effective and safe treatment for DAVF.

Dual antiplatelet therapy after carotid artery stenting: trends and outcomes in a large national database.

BACKGROUND: While dual antiplatelet therapy (dAPT) is standard of care following carotid artery stenting (CAS), the optimal dAPT regimen and duration has not been established. METHODS: We canvassed a large national database (IBM MarketScan) to identify patients receiving carotid endarterectomy (CEA) or CAS for treatment of ischemic stroke or carotid artery stenosis from 2007 to 2016. We performed univariable and multivariable regression methods to evaluate the impact of covariates on post-CAS stroke-free survival, including post-discharge antiplatelet therapy. RESULTS: A total of 79 084 patients diagnosed with ischemic stroke or carotid stenosis received CEA (71 178; 90.0%) or CAS (7906; 10.0%). After adjusting for covariates, <180 days prescribed post-CAS P2Y12-inhibition was associated with increased risk for stroke (<90 prescribed days HR=1.421, 95% CI 1.038 to 1.946; 90-179 prescribed days HR=1.484, 95% CI 1.045 to 2.106). The incidence of hemorrhagic complications was higher during the period of prescribed P2Y12-inhibition (1.16% per person-month vs 0.49% per person-month after discontinuation, P<0.001). The rate of extracranial hemorrhage was nearly six-fold higher while on dAPT (6.50% per patient-month vs 1.16% per patient-month, P<0.001), and there was a trend towards higher rate of intracranial hemorrhage that did not reach statistical significance (5.09% per patient-month vs 3.69% per patient-month, P=0.0556). Later hemorrhagic events beyond 30 days post-CAS were significantly more likely to be extracranial (P=0.028). CONCLUSIONS: Increased duration of post-CAS dAPT is associated with lower rates of readmissions for stroke, and with increased risk of hemorrhagic complications, particularly extracranial hemorrhage. The potential benefit of prolonging dAPT with regard to ischemic complications must be balanced with the corresponding increased risk of predominantly extracranial hemorrhagic complications.

Staged Surgical Resection of Brain Arteriovenous Malformations.

BACKGROUND: Staged treatment of brain arteriovenous malformations (AVMs) is sometimes necessary to minimize risks associated with sudden changes in cerebral hemodynamics. With the increasing availability and optimization of endovascular techniques, multiple surgical resections are rarely necessary, although, due to specific anatomic circumstances, some AVMs still require staged surgery. Here, we describe the largest reported series of staged surgical resections of brain AVMs. METHODS: This is a retrospective review of surgically resected AVMs at a single institution from 1998-2018. Patients who underwent ≥2 resections within 1 year were reviewed. Only those in whom initial resection was terminated with intention for further resection were included in analysis. RESULTS: Twenty patients underwent deliberately staged resection from 1998-2018. Average age at treatment was 36.2 years (SD 16.5 years). Eleven patients (55%) were female, and 12 (60%) had left-sided AVMs. Median Spetzler-Martin grade was 4 (interquartile range [IQR]: 3-4). Average AVM nidus diameter was 5.0 cm (SD 1.7 cm). Seven patients (35%) presented with AVM rupture, and 12 (60%) presented with focal neurologic deficits without hemorrhage. Seventeen patients (85%) underwent preoperative embolization, median number of embolizations was 3 (IQR: 2-4). Three patients (15%) underwent preoperative radiosurgery. Median number of days between surgeries was 28 (IQR: 8-41 days). Perioperative course was complicated by hemorrhage in 3 patients (15%); 1 required decompressive hemicraniectomy prior to the second stage of surgery. Good functional outcome (defined as modified Rankin Scale score ≤2) was achieved in 14 patients (70%). CONCLUSIONS: Staged surgical resection of large and complex AVMs can be performed with good outcomes in carefully selected patients.

Revisiting Stem Cell-Based Clinical Trials for Ischemic Stroke.

Stroke is the leading cause of serious long-term disability, significantly reducing mobility in almost half of the affected patients aged 65 years and older. There are currently no proven neurorestorative treatments for chronic stroke. To address the complex problem of restoring function in ischemic brain tissue, stem cell transplantation-based therapies have emerged as potential restorative therapies. Aligning with the major cell types found within the ischemic brain, stem-cell-based clinical trials for ischemic stroke have fallen under three broad cell lineages: hematopoietic, mesenchymal, and neural. In this review article, we will discuss the scientific rationale for transplanting cells from each of these lineages and provide an overview of published and ongoing trials using this framework.

Outcomes After Cervical Disc Arthroplasty Versus Stand-Alone Anterior Cervical Discectomy and Fusion: A Meta-Analysis.

STUDY DESIGN: Systemic review and meta-analysis. OBJECTIVES: To review and compare surgical outcomes for patients undergoing stand-alone anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA) for the treatment of cervical spine disease. METHODS: A systematic search was performed on PubMed, Medline, and the Cochrane Library. Comparative trials measuring outcomes of patients undergoing CDA and stand-alone ACDF for degenerative spine disease in the last 10 years were selected for inclusion. After data extraction and quality assessment, statistical analysis was performed with R software metafor package. The random-effects model was used if there was heterogeneity between studies; otherwise, the fixed-effects model was used. RESULTS: In total, 12 studies including 859 patients were selected for inclusion in the meta-analysis. Patients undergoing stand-alone ACDF had a statistically significant increase in postoperative segmental angles (mean difference 0.85° [95% confidence interval = 0.35° to 1.35°], P = .0008). Patients undergoing CDA had a decreased rate of developing adjacent segmental degeneration (risk ratio = 0.56 [95% confidence interval = -0.06 to 1.18], P = .0745). Neck Disability Index, Japanese Orthopedic Association score, Visual Analogue Scale of the arm and neck, as well as postoperative cervical angles were similar between the 2 treatments. CONCLUSIONS: When compared with CDA, stand-alone ACDF offers similar clinical outcomes for patients and leads to increased postoperative segmental angles. We encourage further blinded randomized trials to compare rates of adjacent segmental degeneration and other postoperative outcomes between these 2 treatments options.

Treatment of posterior circulation fusiform aneurysms.

OBJECTIVE: Perforator arteries, the absence of an aneurysm discrete neck, and the often-extensive nature of posterior circulation fusiform aneurysms present treatment challenges. There have been advances in microsurgical and endovascular approaches, including flow diversion, and the authors sought to review these treatments in a long-term series at their neurovascular referral center. METHODS: The authors performed a retrospective chart review from 1990 to 2018. Primary outcomes were modified Rankin Scale (mRS) scores and Glasgow Outcome Scale (GOS) scores at follow-up. The authors also examined neurological complication rates. Using regression techniques, they reviewed independent and dependent variables, including presenting features, aneurysm location and size, surgical approach, and pretreatment and posttreatment thrombosis. RESULTS: Eighty-four patients met the inclusion criteria. Their mean age was 53 years, and 49 (58%) were female. Forty-one (49%) patients presented with subarachnoid hemorrhage. Aneurysms were located on the vertebral artery (VA) or posterior inferior cerebellar artery (PICA) in 50 (60%) patients, basilar artery (BA) or vertebrobasilar junction (VBJ) in 22 (26%), and posterior cerebral artery (PCA) in 12 (14%). Thirty-one (37%) patients were treated with microsurgical and 53 (63%) with endovascular approaches. Six aneurysms were treated with endovascular flow diversion. The authors found moderate disability or better (mRS score ≤ 3) in 85% of the patients at a mean 14-month follow-up. The GOS score was ≥ 4 in 82% of the patients. The overall neurological complication rate was 12%. In the regression analysis, patients with VA or PICA aneurysms had better functional outcomes than the other groups (p < 0.001). Endovascular strategies were associated with better outcomes for BA-VBJ aneurysms (p < 0.01), but microsurgery was associated with better outcomes for VA-PICA and PCA aneurysms (p < 0.05). There were no other significant associations between patient, aneurysm characteristics, or treatment features and neurological complications (p > 0.05). Patients treated with flow diversion had more complications than those who underwent other endovascular and microsurgical strategies, but the difference was not significant in regression models. CONCLUSIONS: Posterior circulation fusiform aneurysms remain a challenging aneurysm subtype, but an interdisciplinary treatment approach can result in good outcomes. While flow diversion is a useful addition to the armamentarium, traditional endovascular and microsurgical techniques continue to offer effective options.

Direct versus indirect bypass procedure for the treatment of ischemic moyamoya disease: results of an individualized selection strategy.

OBJECTIVE: The only effective treatment for ischemic moyamoya disease (iMMD) is cerebral revascularization by an extracranial to intracranial bypass. The preferred revascularization method remains controversial: direct versus indirect bypass. The purpose of this study was to test the hypothesis that method choice should be personalized based on angiographic, hemodynamic, and clinical characteristics to balance the risk of perioperative major stroke against treatment efficacy. METHODS: Patients with iMMD were identified retrospectively from a prospectively maintained database. Those with mild to moderate internal carotid artery or M1 segment stenosis, preserved cerebrovascular reserve, intraoperative M4 segment anterograde flow ≥ 8 ml/min, or the absence of frequent and severe transient ischemic attacks (TIAs) or stroke had been assigned to indirect bypass. The criteria for direct bypass were severe ICA or M1 segment stenosis or occlusion, impaired cerebrovascular reserve or steal phenomenon, intraoperative M4 segment retrograde flow or anterograde flow < 8 ml/min, and the presence of frequent and severe TIAs or clinical strokes. The primary study endpoint was MRI-confirmed symptomatic stroke ≤ 7 days postoperatively resulting in a decline in the modified Rankin Scale (mRS) score from preoperatively to 6 months postoperatively. As a secondary endpoint, the authors assessed 6-month postoperative DSA-demonstrated revascularization, which was classified as < 1/3, 1/3-2/3, or > 2/3 of the middle cerebral artery territory. RESULTS: One hundred thirty-eight patients with iMMD affecting 195 hemispheres revascularized in the period from March 2016 to June 2018 were included in this analysis. One hundred thirty-three hemispheres were revascularized with direct bypass and 62 with indirect bypass. The perioperative stroke rate was 4.7% and 6.8% in the direct and indirect groups, respectively (p = 0.36). Degree of revascularization was higher in the direct bypass group (p = 0.03). The proportion of patients improving to an mRS score 0-1 (from preoperatively to 6 months postoperatively) tended to be higher in the direct bypass group, although the difference between the two bypass groups was not statistically significant (p = 0.27). CONCLUSIONS: The selective use of an indirect bypass procedure for iMMD did not decrease the perioperative stroke rate. Direct bypass provided a significantly higher degree of revascularization. The authors conclude that direct bypass is the treatment of choice for iMMD.

Initial experience with the Scepter Mini dual-lumen balloon for transophthalmic artery embolization of anterior cranial fossa dural arteriovenous fistulae.

BACKGROUND: Precise delivery of liquid embolic agents (LEAs) remains a challenge in the endovascular treatment of dural arteriovenous fistulae (dAVFs) and cerebral arteriovenous malformations (cAVMs). Despite significant advances in the past decade, LEA reflux and catheter navigability remain shortcomings of current endovascular technology, particularly in small and tortuous arteries. The Scepter Mini dual-lumen balloon microcatheter aims to address these issues by decreasing the distal catheter profile (1.6 French) while allowing for a small (2.2 mm diameter) balloon at its tip. METHODS: We report our initial experience with the Scepter Mini in two patients with anterior cranial fossa dAVFs that were treated with transophthalmic artery embolization. RESULTS: In both patients, the Scepter Mini catheter was able to be safely advanced into the distal ophthalmic artery close to the fistula site, and several centimeters past the origins of the central retinal and posterior ciliary arteries. A single Onyx injection without any reflux resulted in angiographic cure of the dAVF in both cases, and neither patient suffered any vision loss. CONCLUSIONS: These initial experiences suggest that the Scepter Mini represents a significant advance in the endovascular treatment of dAVFs and cAVMs and will allow for safer and more efficacious delivery of LEAs into smaller and more distal arteries while diminishing the risk of LEA reflux.

Functional Mapping for Glioma Surgery: A Propensity-Matched Analysis of Outcomes and Cost.

OBJECTIVE: To compare clinical outcomes and payments between glioma resections with and without functional mapping. METHODS: The Thomas Reuters MarketScan national longitudinal database was used to identify patients undergoing resection of supratentorial primary malignant glioma with or without functional mapping between 2007 and 2016. Patients were stratified into mapped and unmapped (conventional) groups and subsequently propensity-matched based on demographics, clinical comorbidities, and surgical characteristics (i.e., use of stereotactic navigation, microscope, and intratumoral chemotherapy). Outcomes and charges were compared between matched groups using bivariate analyses. RESULTS: A total of 14,037 patients were identified, of whom 796 (6.0%) received functional mapping. Propensity matching (1:1) resulted in 796 mapped patients and 796 propensity-matched controls. Thirty-day postoperative rates of new-onset seizures, cerebral edema, hemorrhage, and neurologic deficits were significantly lower for the functional mapping group (all P < 0.05). Functional mapping was also associated with shorter hospital length of stay (P = 0.0144), lower 30-day rates of emergency department visits (P = 0.0001), and fewer reoperations (P = 0.0068). Total costs of initial admission were not significantly different between groups. CONCLUSIONS: Intraoperative functional mapping during glioma resection was associated with decreased complications, reoperations, emergency department visits, and shorter lengths of stay. Furthermore, total charges of mapped resections were not significantly different from those of conventional resections. These findings support the usefulness of functional mapping for resection of supratentorial primary malignant gliomas.

Utilization of Novel High-Resolution, MRI-Based Vascular Imaging Modality for Preoperative Stereoelectroencephalography Planning in Children: A Technical Note.

INTRODUCTION: Stereoelectroencephalography (SEEG) is a powerful intracranial diagnostic tool that requires accurate imaging for proper electrode trajectory planning to ensure efficacy and maximize patient safety. Computed tomography (CT) angiography and digital subtraction angiography are commonly used, but recent developments in magnetic resonance angiography allow for high-resolution vascular visualization without added risks of radiation. We report on the accuracy of electrode placement under robotic assistance planning utilizing a novel high-resolution magnetic resonance imaging (MRI)-based imaging modality. METHODS: Sixteen pediatric patients between February 2014 and October 2017 underwent SEEG exploration for epileptogenic zone localization. A gadolinium-enhanced 3D T1-weighted spoiled gradient recalled echo sequence with minimum echo time and repetition time was applied for background parenchymal suppression and vascular enhancement. Electrode placement accuracy was determined by analyzing postoperative CT scans laid over preoperative virtual electrode trajectory paths. Entry point, target point, and closest vessel intersection were measured. RESULTS: For any intersection along the trajectory path, 57 intersected vessels were measured. The mean diameter of an intersected vessel was 1.0343 ± 0.1721 mm, and 21.05% of intersections involved superficial vessels. There were 157 overall intersection + near-miss events. The mean diameter for an involved vessel was 1.0236 ± 0.0928 mm, and superficial vessels were involved in 20.13%. Looking only at final electrode target, 3 intersection events were observed. The mean diameter of an intersected vessel was 1.0125 ± 0.2227 mm. For intersection + near-miss events, 24 were measured. An involved vessel's mean diameter was 1.1028 ± 0.2634 mm. For non-entry point intersections, 45 intersected vessels were measured. The mean diameter for intersected vessels was 0.9526 ± 0.0689 mm. For non-entry point intersections + near misses, 126 events were observed. The mean diameter for involved vessels was 0.9826 ± 0.1008 mm. CONCLUSION: We believe this novel sequence allows better identification of superficial and deeper subcortical vessels compared to conventional T1-weighted gadolinium-enhanced MRI.

Postoperative outcomes following pediatric intracranial electrode monitoring: A case for stereoelectroencephalography (SEEG).

BACKGROUND: For patients with medically refractory epilepsy, intracranial electrode monitoring can help identify epileptogenic foci. Despite the increasing utilization of stereoelectroencephalography (SEEG), the relative risks or benefits associated with the technique when compared with the traditional subdural electrode monitoring (SDE) remain unclear, especially in the pediatric population. Our aim was to compare the outcomes of pediatric patients who received intracranial monitoring with SEEG or SDE (grids and strips). METHODS: We retrospectively studied 38 consecutive pediatric intracranial electrode monitoring cases performed at our institution from 2014 to 2017. Medical/surgical history and operative/postoperative records were reviewed. We also compared direct inpatient hospital costs associated with the two procedures. RESULTS: Stereoelectroencephalography and SDE cohorts both showed high likelihood of identifying epileptogenic zones (SEEG: 90.9%, SDE: 87.5%). Compared with SDE, SEEG patients had a significantly shorter operative time (118.7 versus 233.4 min, P < .001) and length of stay (6.2 versus 12.3 days, P < .001), including days spent in the intensive care unit (ICU; 1.4 versus 5.4 days, P < .001). Stereoelectroencephalography patients tended to report lower pain scores and used significantly less narcotic pain medications (54.2 versus 197.3 mg morphine equivalents, P = .005). No complications were observed. Stereoelectroencephalography and SDE cohorts had comparable inpatient hospital costs (P = .47). CONCLUSION: In comparison with subdural electrode placement, SEEG results in a similarly favorable clinical outcome, but with reduced operative time, decreased narcotic usage, and superior pain control without requiring significantly higher costs. The potential for an improved postoperative intracranial electrode monitoring experience makes SEEG especially suitable for pediatric patients.

Effect of Oxygen Extraction (Brush-Sign) on Baseline Core Infarct Depends on Collaterals (HIR).

Objectives: Baseline-core-infarct volume is a critical factor in patient selection and outcome in acute ischemic stroke (AIS) before mechanical thrombectomy (MT). We determined whether oxygen extraction efficiency and arterial collaterals, two different physiologic components of the cerebral ischemic cascade, interacted to modulate baseline-core-infarct volume in patients with AIS-LVO undergoing MT triage. Methods: Between January 2015 and March 2018, consecutive patients with an AIS and M1 occlusion considered for MT with a baseline MRI and perfusion-imaging were included. Variables such as baseline-core-infarct volume [mL], arterial collaterals (HIR: TMax > 10 s volume/TMax > 6 s), high oxygen extraction (HOE, presence of the brush-sign on T2*) were assessed. A linear-regression was used to test the interaction of HOE and HIR with baseline-core-infarct volume, after including potential confounding variables. Results: We included 103 patients. Median age was 70 (58-78), and 63% were female. Median baseline-core-infarct volume was 32 ml (IQR 8-74.5). Seventy six patients (74%) had HOE. In a multivariate analysis both favorable HIR collaterals (p = 0.02) and HOE (p = 0.038) were associated with lower baseline-core-infarct volume. However, HOE significantly interacted with HIR (p = 0.01) to predict baseline-core-infarct volume, favorable collaterals (low HIR) with HOE was associated with small baseline-core-infarct whereas patients with poor collaterals (high HIR) and HOE had large baseline-core-infarct. Conclusion: While HOE under effective collateral blood-flow has the lowest baseline-core-infarct volume of all patients, the protective effect of HOE reverses under poor collateral blood-flow and may be a maladaptive response to ischemic stroke as measured by core infarctions in AIS-LVO patients undergoing MT triage.

Thrombectomy for acute ischemic stroke in nonagenarians compared with octogenarians.

INTRODUCTION: Multiple randomized trials have shown that endovascular thrombectomy (EVT) leads to improved outcomes in acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Elderly patients were poorly represented in these trials, and the efficacy of EVT in nonagenarian patients remains uncertain. METHODS: We performed a retrospective cohort study at a single center. Inclusion criteria were: age 80-99, LVO, core infarct <70 mL, and salvageable penumbra. Patients were stratified into octogenarian (80-89) and nonagenarian (90-99) cohorts. The primary outcome was the ordinal score on the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included dichotomized functional outcome (mRS ≤2 vs mRS ≥3), successful revascularization, symptomatic intracranial hemorrhage (ICH), and mortality. RESULTS: 108 patients met the inclusion criteria, including 79 octogenarians (73%) and 29 nonagenarians (27%). Nonagenarians were more likely to be female (86% vs 58%; p<0.01); there were no other differences between groups in terms of demographics, medical comorbidities, or treatment characteristics. Successful revascularization (TICI 2b-3) was achieved in 79% in both cohorts. Median mRS at 90 days was 5 in octogenarians and 6 in nonagenarians (p=0.09). Functional independence (mRS ≤2) at 90 days was achieved in 12.5% and 19.7% of nonagenarians and octogenarians, respectively (p=0.54). Symptomatic ICH occurred in 21.4% and 6.4% (p=0.03), and 90-day mortality rate was 63% and 40.9% (p=0.07) in nonagenarians and octogenarians, respectively. CONCLUSIONS: Nonagenarians may be at higher risk of symptomatic ICH than octogenarians, despite similar stroke- and treatment-related factors. While there was a trend towards higher mortality and worse functional outcomes in nonagenarians, the difference was not statistically significant in this relatively small retrospective study.