National multicentered retrospective review of clinical and intraoperative factors associated with the development of cerebellar mutism after pediatric posterior fossa tumor resection.

BACKGROUND: Cerebellar mutism (CM) is characterized by a significant loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains unclear and is the subject of ongoing debate. Significant recovery from CM is less likely than previously described despite rigorous multidisciplinary neuro-rehabilitational efforts. METHODS: A national multi-centered retrospective review of all children undergoing PF resection in four midsized Canadian academic pediatric institutions was undertaken. Patient, tumor and surgical factors associated with the post-operative development of CM were reviewed. Retrospective identification of PF surgery patients including those developing and those that did not (internal control). RESULTS: The study identified 258 patients across the 4 centers between 2010 and 2020 (mean age 6.73 years; 42.2% female). Overall, CM was experienced in 19.5% of patients (N = 50). Amongst children who developed CM histopathology included medulloblastoma (35.7%), pilocytic astrocytoma (32.6%) and ependymoma (17.1%). Intraoperative impression of adherence to the floor of the 4th ventricle was positive in 36.8%. Intraoperative abrupt changes in blood pressure and/or heart rate were identified in 19.4% and 17.8% of cases. The clinical resolution of CM was rated to be complete, significant resolution, slight improvement, no improvement and deterioration in 56.0%, 8.0%, 20.0%, 14.0% and 2.0%, respectively. In the cohort of children who experienced post-operative CM as compared to their no-CM counterpart, proportionally more tumors were felt to be adherent to the floor of the 4th ventricle (56.0% vs 49.5%), intraoperative extent of resection was a GTR (74% vs 68.8%) and changes in heart rate were noted (≥ 20% from baseline) (26.0% vs 15.9%). However, a multiple regression analysis identified only abrupt changes in HR (OR 5.97, CI (1.53, 23.1), p = 0.01) to be significantly associated with the development of post-operative CM. CONCLUSION: As a devastating surgical complication after posterior fossa tumor surgery with variable clinical course, identifying and understanding the operative cues and revising intraoperative plans that optimizes the child's neurooncological and clinical outcome are essential.

Optimal Glucose Target After Aneurysmal Subarachnoid Hemorrhage: A Matched Cohort Study.

BACKGROUND: Hyperglycemia has been associated with poor outcomes in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, there remains debate as to what optimal glucose targets should be in this patient population. OBJECTIVE: To assess whether we could identify an optimal glucose target for patients with aSAH. METHODS: We performed a post hoc analysis of the "clazosentan to overcome neurological ischemia and infarction occurring after subarachnoid hemorrhage" trial data set. Patients had laboratory results drawn daily for the entirety of their intensive care unit stay. Maximum blood glucose levels were assessed for a relationship with unfavorable outcomes using multiple logistic regression analysis. Maximum blood glucose levels were dichotomized based on the Youden index, which identified a maximum level of <9.2 mmol/L as the optimal cut point for prediction of unfavorable outcomes. Nearest neighbor matching was used to assess the relationship between maintaining glucose levels below the cut point and unfavorable functional outcomes (defined as a modified Rankin score of >2 at 3 mo post-aSAH). The matching was performed after calculation of a propensity score based on identified predictors of outcome and glucose levels. RESULTS: Three hundred eighty-nine patients were included in the matched analysis. Propensity scores were balanced on both the covariates and outcomes of interest. There was a significant average treatment effect (-0.143: 95% confidence interval -0.267 to -0.019) for patients who maintained glucose levels <9.2 mmol/L. CONCLUSION: Maintaining glucose levels below the identified cut point was associated with a decreased risk for unfavorable outcomes in this retrospective matched study.

Learning curves for transradial access versus transfemoral access in diagnostic cerebral angiography: a case series.

BACKGROUND: The perception of a steep learning curve associated with transradial access has resulted in its limited adoption in neurointervention despite the demonstrated benefits, including decreased access-site complications. OBJECTIVE: To compare learning curves of transradial versus transfemoral diagnostic cerebral angiograms obtained by five neurovascular fellows as primary operator. METHODS: The first 100-150 consecutive transradial and transfemoral angiographic scans performed by each fellow between July 2017 and March 2020 were identified. Mean fluoroscopy time per artery injected (angiographic efficiency) was calculated as a marker of technical proficiency and compared for every 25 consecutive procedures performed (eg, 1-25, 26-50, 51-75). RESULTS: We identified 1242 diagnostic angiograms, 607 transradial and 635 transfemoral. The radial cohort was older (64.3 years vs 62.3 years, p=0.01) and demonstrated better angiographic efficiency (3.4 min/vessel vs 3.7 min/vessel, p=0.03). For three fellows without previous endovascular experience, proficiency was obtained between 25 and 50 transfemoral angiograms. One fellow achieved proficiency after performing 25-50 transradial angiograms; and the two other fellows, in <25 transradial angiograms. The two fellows with previous experience had flattened learning curves for both access types. Two patients experienced transient neurologic symptoms postprocedure. Transradial angiograms were associated with significantly fewer access-site complications (3/607, 0.5% vs 22/635, 3.5%, p<0.01). Radial-to-femoral conversion occurred in 1.2% (7/607); femoral-to-radial conversion occurred in 0.3% (2/635). Over time, the proportion of transradial angiographic procedures increased. CONCLUSION: Technical proficiency improved significantly over time for both access types, typically requiring between 25 and 50 diagnostic angiograms to achieve asymptomatic improvement in efficiency. Reduced access-site complications and decreased fluoroscopy time were benefits associated with transradial angiography.

A nationwide prospective multicenter study of external ventricular drainage: accuracy, safety, and related complications.

OBJECTIVE: External ventricular drainage (EVD) catheters are associated with complications such as EVD catheter infection (ECI), intracranial hemorrhage (ICH), and suboptimal placement. The aim of this study was to investigate the rates of EVD catheter complications and their associated risk factor profiles in order to optimize the safety and accuracy of catheter insertion. METHODS: A total of 348 patients with urgently placed EVD catheters were included as a part of a prospective multicenter observational cohort. Strict definitions were applied for each complication category. RESULTS: The rates of misplacement, ECI/ventriculitis, and ICH were 38.6%, 12.2%, and 9.2%, respectively. Catheter misplacement was associated with midline shift (p = 0.002), operator experience (p = 0.031), and intracranial length (p < 0.001). Although mostly asymptomatic, ICH occurred more often in patients receiving prophylactic low-molecular-weight heparin (LMWH) (p = 0.002) and those who required catheter replacement (p = 0.026). Infectious complications (ECI/ventriculitis and suspected ECI) occurred more commonly in patients whose catheters were inserted at the bedside (p = 0.004) and those with smaller incisions (≤ 1 cm) (p < 0.001). ECI/ventriculitis was not associated with preinsertion antibiotic prophylaxis (p = 0.421), catheter replacement (p = 0.118), and catheter tunneling length (p = 0.782). CONCLUSIONS: EVD-associated complications are common. These results suggest that the operating room setting can help reduce the risk of infection, but not the use of preoperative antibiotic prophylaxis. Although EVD-related ICH was associated with LMWH prophylaxis for deep vein thrombosis, there were no significant clinical manifestations in the majority of patients. Catheter misplacement was associated with operator level of training and midline shift. Information from this multicenter prospective cohort can be utilized to increase the safety profile of this common neurosurgical procedure.

Preoperative Embolization of Fisch Grades II-IVa Juvenile Nasopharyngeal Angiofibromas: Transarterial Embolization in the Age of Onyx.

Objective The current mainstay treatment for juvenile nasopharyngeal angiofibromas (JNAs) is surgical resection, but embolization of primary feeding arteries through endovascular transarterial and direct tumoral puncture embolizations with various agents has been described. We describe a single institutional experience with JNA embolization utilizing Onyx (Medtronic, Dublin, Ireland). Methods A retrospective records review was performed to identify patients who underwent embolization for devascularization of Fisch grades II-IVa JNA (tumor extension beyond the sphenopalatine region) before surgical resection between 2010 and 2019. Fluoroscopy time, grade, intraoperative blood loss, and clinical follow-up data were compiled. Tumor devascularization percentage was calculated using ImageJ software (public domain, BSD-2) by measuring the ratio of preoperative and postoperative embolization tracing. Results Five consecutive patients (ages 12-16 years [average 14 years]; all male) with JNAs underwent preoperative transarterial embolizations performed under general anesthesia. All patients presented with epistaxis; two also presented with headaches. Fisch grades were II in two patients, IIIa in two, and IVa in one. The patient with the grade IVa lesion underwent direct transtumoral puncture and Onyx embolization. The mean percentage of all tumor devascularizations postembolization was 86.0±9.7%.Complete resection 24-48 hours postembolization was obtained for grades II and IIIa lesions with <700 mL blood loss. No embolization-related complications and no clinical sequelae were present in the five cases after embolization. Conclusion In our experience, Onyx embolization of JNAs was safely conducted with adequate tumor penetration beyond the sphenopalatine region through transarterial routes.

Gene expression profiling of brain endothelial cells after experimental subarachnoid haemorrhage.

Subarachnoid haemorrhage (SAH) is a type of hemorrhagic stroke that is associated with high morbidity and mortality. New effective treatments are needed to improve outcomes. The pathophysiology of SAH is complex and includes early brain injury and delayed cerebral ischemia, both of which are characterized by blood-brain barrier (BBB) impairment. We isolated brain endothelial cells (BECs) from mice subjected to SAH by injection of blood into the prechiasmatic cistern. We used gene expression profiling to identify 707 unique genes (2.8% of transcripts, 403 upregulated, 304 downregulated, 24,865 interrogated probe sets) that were significantly differentially expressed in mouse BECs after SAH. The pathway involving prostaglandin synthesis and regulation was significantly upregulated after SAH, including increased expression of the Ptgs2 gene and its corresponding COX-2 protein. Celecoxib, a selective COX-2 inhibitor, limited upregulation of Ptgs2 in BECs. In this study, we have defined the gene expression profiling of BECs after experimental SAH and provide further insight into BBB pathophysiology, which may be relevant to other neurological diseases such as traumatic brain injury, brain tumours, ischaemic stroke, multiple sclerosis, and neurodegenerative disorders.

Complete flow control using transient concurrent rapid ventricular pacing or intravenous adenosine and afferent arterial balloon occlusion during transvenous embolization of cerebral arteriovenous malformations: case series.

BACKGROUND: There are no reports that describe complete flow control using concurrent transient rapid ventricular pacing or intravenous (IV) adenosine and afferent arterial balloon flow arrest to aid transvenous embolization of cerebral arteriovenous malformations (AVM). We describe our experience with the use of this technique in patients undergoing transvenous AVM embolization. METHODS: Consecutive patients in whom transvenous embolization was attempted at our institute between January 2017 and July 2019 were included. Anatomical AVM features, number of embolization stages, technique of concurrent transient rapid ventricular pacing and afferent arterial balloon flow arrest, complications, and clinical and radiological outcomes were recorded and tabulated. RESULTS: Transvenous AVM embolization was attempted in 12 patients but abandoned in two patients for technical reasons. Complete embolization was achieved in 10 patients, five of whom had infratentorial AVMs. All 10 had a single primary draining vein. Rapid ventricular pacing was used in nine cases; IV adenosine injection was used in one case to achieve cardiac standstill. Complete AVM nidus obliteration was achieved with excellent neurologic outcome in nine cases, with transvenous embolization alone in two cases, and with staged transarterial followed by transvenous embolization in the others. Two patients developed hemorrhagic complications intraprocedurally. One patient was managed conservatively and the other operatively with AVM excision and hematoma evacuation; both made an excellent recovery without any neurologic deficits at 3 months. CONCLUSION: Complete flow control using concurrent transient rapid ventricular pacing with afferent arterial balloon flow arrest technique is safe and feasible for transvenous embolization of select AVMs.

Endovascular management of radial artery loop for neuroangiography: Case series.

BACKGROUND: Radial loops are rare congenital radial artery anomalies that may pose a significant challenge to successful transradial neuroangiography. In this case series, we describe the anatomy and frequency of radial artery loops and provide a technique for successful navigation of this anatomic anomaly. METHODS: We reviewed our database of radial diagnostic or interventional neuroangiographic procedures to identify cases in which a radial loop was encountered during the procedure. The loop pattern, the presence of an associated recurrent radial artery branch, navigation technique, and procedure-related complications were recorded. A descriptive analysis was performed. RESULTS: A total of 997 transradial approach procedures were performed over a 9-month period. A radial loop was identified in 10 (1.0%) patients. The average age was 68.6 ± 14.3 years. A microcatheter advanced over a microwire was used to navigate the loop and avoid entry into the recurrent branch. A diagnostic neuroangiographic procedure was performed successfully in 8 cases and an intervention was performed successfully in 1 case. A 360° loop was present in 2 of these cases. In each case, transradial access was performed successfully. In 1 other diagnostic case, transradial access was aborted, and the femoral artery was accessed to perform the procedure. CONCLUSIONS: A radial loop was present in 1% of the cases in this series. Our technical results suggest that this anomaly should not be considered a contraindication to transradial neuroangiography because the procedure was successfully performed in most (9 of 10) cases using a microcatheter system to navigate the loop.

Coil Occlusion of Right M2 Fusiform Aneurysm After Balloon-Test Occlusion: 2-Dimensional Video.

We present a 73-year-old man with an incidental right M2 fusiform aneurysm demonstrating growth on serial noninvasive imaging over 5 years (Video 1). After multidisciplinary conference review, the decision was to proceed with intracranial balloon-test occlusion (BTO) followed by coil occlusion if the patient passed this test or by trap and bypass if the patient failed this test. With the patient under moderate conscious sedation, a transfemoral 8F approach was used with positioning of a TracStar 95-cm 088 guide catheter (Imperative Care, Campbell, California, USA) into the distal right cervical ICA. We positioned a Scepter 4-mm × 10-mm compliant dual-lumen balloon microcatheter (MicroVention, Alisa Viejo, California, USA) into the proximal M2. The patient passed the 30-minute BTO including a 15-minute hypotensive challenge with nitroprusside infusion. Our goal was to occlude the aneurysm from distal to proximal for precise thrombosis. A Phenom 17 150-cm microcatheter (Medtronic, Dublin, Ireland) separate from the Scepter balloon microcatheter was positioned in the distal portion of the aneurysm. Coil occlusion was successfully performed with an assortment of complex and helical coils. Sluggish anterograde flow was seen distal to the aneurysm with prominent retrograde filling of the distal right MCA territory via pial collaterals from the right PCA. The patient tolerated the procedure well and was discharged the following day neurologically intact. Six-month follow-up diagnostic angiogram confirmed complete occlusion of the aneurysm. This is the first published video using the elegant approach of intracranial BTO followed by coil occlusion for an intracranial fusiform aneurysm using a dual-lumen balloon microcatheter.

Safety and feasibility of ulnar artery access for neuroangiography and neurointervention: a case series.

BACKGROUND: Radial access has become popular among neurointerventionalists because it has favorable risk profiles compared with femoral access. Difficulties in accessing or navigating the radial artery have been viewed as a reason to convert to femoral access, but ulnar artery access may prevent complications associated with transfemoral procedures. OBJECTIVE: To evaluate the safety and feasibility of ulnar access for neurointerventions and diagnostic neuroangiographic procedures. METHODS: Consecutive patients who underwent diagnostic angiography or neurointerventional procedures via ulnar access between July 1, 2019 and April 15, 2020 were included. Data recorded were demographics, procedure indication, devices, technique, and complications. Descriptive analysis was performed. RESULTS: Ulnar artery access was obtained for 21 procedures in 18 patients (mean age 70.3±7.8 years; nine men). Procedures included 13 diagnostic angiograms and eight neurointerventions (3 left middle meningeal artery embolization, 1 of which was aborted; 2 carotid artery stenting; 2 angioplasty; 1 mechanical thrombectomy for in-stent thrombosis). A right-sided approach with ultrasound guidance was used for all cases except one. Indications included small caliber radial artery (n=9), radial artery occlusion (n=10), and radial artery preservation for potential bypass (n=2). A 5-French slender sheath was used for diagnostic angiography; a 6-French slender sheath was used for neurointerventions. No case required conversion to femoral access. Two patients had minor hematomas after the procedure; one other had ulnar artery occlusion on 30-day ultrasonography. CONCLUSION: Ulnar access is safe and feasible for diagnostic and interventional neuroangiographic procedures. It provides a useful alternative to radial access, potentially avoiding complications associated with femoral access.

Transradial access for flow diversion of intracranial aneurysms: Case series.

BACKGROUND: Transradial access for neurointerventions offers advantages of fewer access-site complications, reduced procedure time, and greater patient comfort over transfemoral access. Data about transradial access for flow diversion are limited. We share our early experience with transradial access for flow diversion in a relatively large case series. METHODS: Consecutive patients who underwent Pipeline embolization device (Medtronic) deployment via transradial access were included in the study, irrespective of location and laterality of the intracranial aneurysm. The cases were performed between July 2016 and October 2019. Demographics, aneurysm characteristics, and procedure-related details (including catheter systems used) were recorded and statistically evaluated. RESULTS: Thirty-five transradial flow diversion procedures were attempted in 32 patients, of which 33 procedures were successful. In two cases involving left common carotid artery and internal carotid artery access, guide catheter herniation into the aortic arch led to abandonment of transradial access in favor of transfemoral access. The most common aneurysm locations in the transradial access procedures were the posterior communicating artery (n = 7), ophthalmic artery (n = 7), and superior hypophyseal artery (n = 7). Most transradial access procedures (66.7%) were performed using a biaxial catheter system. 6-French Benchmark (Penumbra) and Phenom 27 (Medtronic) were the most commonly utilized guide- and microcatheters, respectively. One patient had intraprocedural subarachnoid hemorrhage. No access-site complications occurred. CONCLUSION: This study demonstrates safety and feasibility of transradial access for Pipeline embolization device deployment and shows the versatility of this approach for different catheter systems. Tortuosity and acute angulation of the left common carotid artery and internal carotid artery were associated with approach failure.

Unfavorable Outcome After Good Grade Aneurysmal Subarachnoid Hemorrhage: Exploratory Analysis.

OBJECTIVE: Patients with good-grade aneurysmal subarachnoid hemorrhage (aSAH) are thought to recover well, yet some do not. This work sought to identify predictors of unfavorable functional outcome after good-grade aSAH. METHODS: We performed a post-hoc analysis of the CONSCIOUS-1 trial. Patients with World Federation of Neurosurgical Societies grades I or II aSAH were included. The primary outcome was unfavorable functional outcome (defined as a modified Rankin Scale score >2) at 12 weeks. Parametric and nonparametric testing were used as appropriate. Variables were classified as modifiable or nonmodifiable, depending on whether they were present at patient admission. Stepwise logistic regression models were created for modifiable and nonmodifiable predictors of outcome. Independent predictors in the respective multivariate analyses were combined into a final multivariate regression model. RESULTS: We included 301 patients, 67 of whom (22%) had an unfavorable outcome. Of the nonmodifiable predictors, higher admission systolic blood pressure (P = 0.002) and female sex (P = 0.011) were independently associated with unfavorable outcome. Potentially modifiable independent predictors of outcome were delayed cerebral ischemia (P = 0.039), higher maximum temperature (0.036), suffering a respiratory system complication (P = 0.004), and suffering an intracranial hemorrhagic complication (P = 0.022). All variables found to be independently predictive of poor outcome in their respective models retained statistical significance in the combined multivariate analysis. CONCLUSIONS: About 1 in 5 good-grade aSAH patients enrolled in CONSCIOUS-1 suffered an unfavorable functional outcome. Admission systolic blood pressure, female sex, hyperthermia, delayed cerebral ischemia, respiratory complications, and intracranial hemorrhagic complications may be predictive of outcome.

A data-driven model to identify high-risk aneurysms and guide management decisions: the Rupture Resemblance Score.

OBJECTIVE: Previous studies have found that ruptured intracranial aneurysms (RIAs) have distinct morphological and hemodynamic characteristics, including higher size ratio and oscillatory shear index and lower wall shear stress. Unruptured intracranial aneurysms (UIAs) that possess similar characteristics to RIAs may be at a higher risk of rupture than those UIAs that do not. The authors previously developed the Rupture Resemblance Score (RRS), a data-driven computer model that can objectively gauge the similarity of UIAs to RIAs in terms of morphology and hemodynamics. The authors aimed to explore the clinical utility of RRS in guiding the management of UIAs, especially for challenging cases such as small UIAs. METHODS: Between September 2018 and June 2019, the authors retrospectively collected consecutive challenging cases of incidentally identified UIAs that were discussed during their weekly multidisciplinary neurovascular conference. From patient 3D digital subtraction angiography, they reconstructed the aneurysm geometry and performed computer-assisted 3D morphology analysis and computational fluid dynamics simulation. They calculated RRS for every UIA case and compared it against the treatment decision made at the neurovascular conference as well as the recommendation based on the unruptured intracranial aneurysm treatment score (UIATS). RESULTS: Forty-seven patients with 79 UIAs, 90% of which were < 7 mm in size, were included in this study. The mean RRS (range 0.0-1.0) was 0.24 ± 0.31. At the conferences, treatment was endorsed for 45 of the UIAs (57%). These cases had significantly higher RRSs than the 34 cases suggested for observation (0.33 ± 0.34 vs 0.11 ± 0.19, p < 0.001). The UIATS-based recommendations were "observation" for 24 UIAs (30%), "treatment" for 21 UIAs (27%), and "not definitive" for 34 UIAs (43%). These "not definitive" cases were stratified by RRS based on similarity to RIAs. CONCLUSIONS: Although not a rupture predictor, RRS is a data-driven model that gauges the similarity of UIAs to RIAs in terms of morphology and hemodynamics. In cases in which the UIATS-based recommendation is not definitive, RRS provides additional stratification to assist the identification of high-risk UIAs. The current study highlights the clinical utility of RRS in a real-world setting as an adjunctive tool for the management of UIAs.

Transition to Transradial Access for Mechanical Thrombectomy-Lessons Learned and Comparison to Transfemoral Access in a Single-Center Case Series.

BACKGROUND: Trends in mechanical thrombectomy have emphasized larger bore aspiration catheters that may be difficult to deploy from a radial access point due to size constraints or need to obtain sheathless access. As such, many neurointerventionists are reticent to attempt thrombectomy through transradial access (TRA) for fear of worse outcomes. OBJECTIVE: To explore whether mechanical thrombectomy could be achieved safely and effectively through the transradial route. METHODS: We retrospectively analyzed the records of patients undergoing mechanical thrombectomy at our academic institute between January 2018 and January 2019, which corresponded to a time when we began to transition to TRA for neurointerventions, including mechanical thrombectomy. We compared the procedural details and clinical outcomes of patients undergoing mechanical thrombectomy using TRA with those using transfemoral access (TFA). RESULTS: During the study period, 44 patients underwent mechanical thrombectomy with TRA and 129 with TFA. There was no statistically significant difference in door-to-access time, door-to-reperfusion time, or first-pass recanalization rate. There was no significant difference in modified Rankin Scale (mRS) score at discharge, mRS score at last follow-up, or length of stay. There were 7 access-site complications in the TFA group and none in the TRA group. One patient in the TRA group required crossover to TFA. CONCLUSION: Mechanical thrombectomy can be performed safely and effectively from a TRA site without compromising recanalization times or rates. TRA has superior access-site complication profiles compared to TFA.

Transradial middle meningeal artery embolization for chronic subdural hematoma using Onyx: case series.

BACKGROUND: Middle meningeal artery (MMA) embolization is an emerging therapy for the resolution of subacute or chronic subdural hematoma (CSDH). CSDH patients are often elderly and have several comorbidities. We evaluated our experience with transradial access (TRA) for MMA embolization using predominantly Onyx under conscious sedation. METHODS: Data for consecutive patients who underwent transradial MMA embolization for CSDH during a 2-year period (2018-2019) were analyzed from a single-center, prospectively-maintained database. Patient demographics, comorbidities, ambulatory times, subdural hematoma resorption status, and guide catheter type were recorded. Conversion to femoral access and complication rates were also recorded. Univariate and multivariate analyses were performed. RESULTS: Forty-six patients (mean age, 71.7±14.4 years) were included in this study. Mean CSDH size was 14±5.5 mm. Most (91.3%) TRA embolizations were performed with 6-French 0.071-inch Benchmark guide catheters (Penumbra). MMA embolization was successful in 44 patients (95.7%) (including two cases of TRA conversion). Twenty-one (48%) patients had a severe Charlson Comorbidity Index (>5). Symptomatic improvement was noted in 39 of 44 patients (88.6%). Mean length of stay was 4±3 days. Patients were ambulated immediately postprocedure. At mean follow-up (8±4 weeks), 86.4% of patients had complete or partial CSDH resolution. Persistent use of antiplatelet agents after the procedure was associated with failed or minimal CSDH resorption (5 of 6, 83.3% vs 9 of 38 23.7% with complete or near-complete resolution; P=0.009). CONCLUSION: Transradial Onyx MMA embolization under conscious sedation is safe and effective for CSDH treatment. TRA may be especially useful in elderly patients with numerous comorbidities.

Measurement of instant flow reserve to quantify functional flow limitation across stenosis in intracranial atherosclerotic disease.

Angiographic stenosis may not be an accurate reflection of physiological flow limitation. Measurement of instant flow reserve (IFR) to quantify functional flow limitation across stenosis may be valuable in identifying lesions causing significant flow limitation. A case of left middle cerebral artery atherosclerotic disease is presented. Because medical therapy had failed, endovascular revascularization was chosen. In this video 1, IFR measurement to guide submaximal balloon angioplasty with a 1.5×9 mm non-compliant Mini-Trek balloon (Abbott) is demonstrated. Pressure gradient across the middle cerebral artery-M1 stenosis was measured with a Volcano pressure wire (Philips) before and after submaximal balloon angioplasty. An excellent radiographic result and flow improvement into the severely stenosed segment were achieved, with an IFR increase from 0.23 to 0.89. The degree of corresponding stenosis changed from 85% to 30%. No periprocedural complication was observed. IFR can help to identify lesions requiring treatment in select patients and prevent the tendency to overtreat a lesion that is not physiologically significant.

Mechanical thrombectomy of right internal carotid artery terminus occlusion using the ADAPT technique: impact of aspiration on parent vessel.

The impact of ADAPT-"a direct aspiration first pass technique"-on intracranial vasculature is not well understood, since the change of arterial diameter is often not visible during aspiration. We present a unique case in which the impact of aspiration on the parent vessel was visualized due to a previously deployed Neuroform Atlas stent and a Pipeline embolization device. The patient presented with right internal carotid artery occlusion. An aspiration catheter was advanced over the microcatheter system and corked into the clot, located within the stents in proximal M1. The stents were seen to collapse both during electronic pump and hand aspiration with no evidence of stent migration. This demonstrates that it is crucial to engage the clot interface with the tip of the aspiration catheter while performing ADAPT. Placing the aspiration catheter remote from the clot may result in collapse of the artery proximal to the clot with subsequent ADAPT failure.(video 1) neurintsurg;12/11/1148/V1F1V1video 1.

Navigating a proximal loop in the radial artery and avoiding the recurrent radial artery.

Several anatomical variations of the radial artery have been described in the literature. Common variations include radial artery loop, recurrent branch, and anastomotic channels connecting the radial and brachial arteries. These variations can pose significant technical challenges to safe radial artery catheterization. Because radial access for neurointervention is becoming popular, appreciation of these variations and mastery of techniques for safe radial artery catheterization are of paramount importance. In this operative video,(video 1) we present a case of a 75-year-old man who underwent middle meningeal artery embolization for treatment of chronic subdural hematoma using a transradial approach. The patient was found to have a radial artery loop and a recurrent branch off the radial artery. The loop could not be negotiated with the conventional technique. We therefore used a microcatheter system with a stiff microwire to navigate and straighten the radial loop under road map guidance. The remaining procedure was performed successfully.

Treatment of Carotid Ophthalmic Aneurysm With Woven EndoBridge (WEB SL): 2-Dimensional Operative Video.

Wide-necked cerebral aneurysms often require complex treatment strategies for optimal treatment. As the surgeon's arsenal continues to expand, consideration of all potential applications of available devices is important. The Woven EndoBridge (WEB) device (MicroVention-Terumo, Aliso Viejo, California) capitalizes on flow disruption to promote thrombosis and is Food and Drug Administration (FDA) approved for saccular wide-necked bifurcation aneurysms located at the middle cerebral artery bifurcation, internal carotid artery (ICA) terminus, anterior communicating artery complex, and basilar apex. In this video, we demonstrate an off-label use of the WEB to treat a wide-necked type II1 ophthalmic artery aneurysm, highlighting the importance of correct device sizing. The patient is a 74-yr-old woman with a family history of aneurysms. Her aneurysm was found incidentally after a minor trauma. Observation and various treatment options were considered. The patient preferred to avoid open surgical intervention and dual antiplatelet therapy. Endoluminal flow diversion for types II and III ophthalmic artery aneurysms has relatively low occlusion rates and a higher incidence of visual field deficits.1 A WEB device can be an excellent alternative to treat these aneurysms. A biaxial system was used to selectively catheterize the supraclinoid internal carotid artery and then the aneurysm, and optimal flow diversion was achieved. The patient did well and was discharged home the next day on aspirin alone. Six-month angiography showed near-occlusion of the aneurysm and ophthalmic artery patency. The neck remnant will be followed up with repeat angiography in 6 mo. The patient gave informed consent for the procedure and video recording. Institutional review board approval was deemed unnecessary. Video ©University at Buffalo Neurosurgery, 2019. With permission.