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OBJECTIVE There is a reported elevated risk of cerebral aneurysms in patients with intracranial dural arteriovenous fistulas (dAVFs). However, the natural history, rate of spontaneous regression, and ideal treatment regimen are not well characterized. In this study, the authors aimed to describe the characteristics of patients with dAVFs and intracranial aneurysms and propose a classification system. METHODS The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database from 12 centers was retrospectively reviewed. Analysis was performed to compare dAVF patients with (dAVF+ cohort) and without (dAVF-only cohort) concomitant aneurysm. Aneurysms were categorized based on location as a dAVF flow-related aneurysm (FRA) or a dAVF non–flow-related aneurysm (NFRA), with further classification as extra- or intradural. Patients with traumatic pseudoaneurysms or aneurysms with associated arteriovenous malformations were excluded from the analysis. Patient demographics, dAVF anatomical information, aneurysm information, and follow-up data were collected. RESULTS Of the 1077 patients, 1043 were eligible for inclusion, comprising 978 (93.8%) and 65 (6.2%) in the dAVF-only and dAVF+ cohorts, respectively. There were 96 aneurysms in the dAVF+ cohort; 10 patients (1%) harbored 12 FRAs, and 55 patients (5.3%) harbored 84 NFRAs. Dural AVF+ patients had higher rates of smoking (59.3% vs 35.2%, p < 0.001) and illicit drug use (5.8% vs 1.5%, p = 0.02). Sixteen dAVF+ patients (24.6%) presented with aneurysm rupture, which represented 16.7% of the total aneurysms. One patient (1.5%) had aneurysm rupture during follow-up. Patients with dAVF+ were more likely to have a dAVF located in nonconventional locations, less likely to have arterial supply to the dAVF from external carotid artery branches, and more likely to have supply from pial branches. Rates of cortical venous drainage and Borden type distributions were comparable between cohorts. A minority (12.5%) of aneurysms were FRAs. The majority of the aneurysms underwent treatment via either endovascular (36.5%) or microsurgical (15.6%) technique. A small proportion of aneurysms managed conservatively either with or without dAVF treatment spontaneously regressed (6.2%). CONCLUSIONS Patients with dAVF have a similar risk of harboring a concomitant intracranial aneurysm unrelated to the dAVF (5.3%) compared with the general population (approximately 2%–5%) and a rare risk (0.9%) of harboring an FRA. Only 50% of FRAs are intradural. Dural AVF+ patients have differences in dAVF angioarchitecture. A subset of dAVF+ patients harbor FRAs that may regress after dAVF treatment.

BackgroundRadial artery access for transarterial procedures has gained recent traction in neurointerventional due to decreased patient morbidity, technical feasibility, and improved patient satisfaction. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for the neurointerventionalist, but data are limited. Our objective was to quantify the use of UETV access in neurointerventions and to measure failure and complication rates.MethodsAn international multicenter retrospective review of medical records for patients undergoing UETV neurointerventions or diagnostic procedures was performed. We also present our institutional protocol for obtaining UETV and review the existing literature.ResultsOne hundred and thirteen patients underwent a total of 147 attempted UETV procedures at 13 centers. The most common site of entry was the right basilic vein. There were 21 repeat puncture events into the same vein following the primary diagnostic procedure for secondary interventional procedures without difficulty. There were two minor complications (1.4%) and five failures (ie, conversion to femoral vein access) (3.4%).ConclusionsUETV is safe and technically feasible for diagnostic and neurointerventional procedures. Further studies are needed to determine the benefit over alternative venous access sites and the effect on patient satisfaction.

Background Lung carcinoma metastasizing to a skull base meningioma remains an extremely rare phenomenon, with only 3 studies reported. Furthermore, no documented cases have been reported in the petroclival region. Thus, we have presented the first 2 cases of tumor-to-tumor metastasis (TTM) in which a petroclival lesion, initially thought to be purely meningioma, was also found to contain metastatic lung adenocarcinoma. Case Description We present the cases of 2 patients with a known history of lung adenocarcinoma and stable petroclival meningioma who had presented with new-onset neurologic deficits. Repeat imaging studies for both patients found an increased lesion size and peritumoral enhancement; thus, both patients underwent emergent craniotomy for complete lesion resection. Intraoperatively, both lesions had zones of markedly different tumoral texture. On histologic analysis, both lesions showed metastatic lung adenocarcinoma contained within the primary petroclival meningioma. Conclusion Skull base TTM is a rare entity for which no specific management guidelines have been created. Therefore, even if the imaging characteristics suggest a more benign process, skull base TTM should remain high on the differential diagnosis for patients with a known primary cancer and new-onset, rapidly progressive, neurologic deficits. Close clinical follow-up with short-interval repeat imaging in this subset of patients might prevent misdiagnosis and facilitate prompt treatment.

OBJECTIVE Cranial dural arteriovenous fistulas (dAVFs) are often treated with endovascular therapy, but occasionally a multimodality approach including surgery and/or radiosurgery is utilized. Recurrence after an initial angiographic cure has been reported, with estimated rates ranging from 2% to 14.3%, but few risk factors have been identified. The objective of this study was to identify risk factors associated with recurrence of dAVF after putative cure. METHODS The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) data were retrospectively reviewed. All patients with angiographic cure after treatment and subsequent angiographic follow-up were included. The primary outcome was recurrence, with risk factor analysis. Secondary outcomes included clinical outcomes, morbidity, and mortality associated with recurrence. Risk factor analysis was performed comparing the group of patients who experienced recurrence with those with durable cure (regardless of multiple recurrences). Time-to-event analysis was performed using all collective recurrence events (multiple per patients in some cases). RESULTS Of the 1077 patients included in the primary CONDOR data set, 457 met inclusion criteria. A total of 32 patients (7%) experienced 34 events of recurrence at a mean of 368.7 days (median 192 days). The recurrence rate was 4.5% overall. Kaplan-Meier analysis predicted long-term recurrence rates approaching 11% at 3 years. Grade III dAVFs treated with endovascular therapy were statistically significantly more likely to experience recurrence than those treated surgically (13.3% vs 0%, p = 0.0001). Tentorial location, cortical venous drainage, and deep cerebral venous drainage were all risk factors for recurrence. Endovascular intervention and radiosurgery were associated with recurrence. Six recurrences were symptomatic, including 2 with hemorrhage, 3 with nonhemorrhagic neurological deficit, and 1 with progressive flow-related symptoms (decreased vision). CONCLUSIONS Recurrence of dAVFs after putative cure can occur after endovascular treatment. Risk factors include tentorial location, cortical venous drainage, and deep cerebral drainage. Multimodality therapy can be used to achieve cure after recurrence. A delayed long-term angiographic evaluation (at least 1 year from cure) may be warranted, especially in cases with risk factors for recurrence.

OBJECTIVE Cranial dural arteriovenous fistulas (dAVFs) are rare lesions, hampering efforts to understand them and improve their care. To address this challenge, investigators with an established record of dAVF investigation formed an international, multicenter consortium aimed at better elucidating dAVF pathophysiology, imaging characteristics, natural history, and patient outcomes. This report describes the design of the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) and includes characterization of the 1077-patient cohort. METHODS Potential collaborators with established interest in the field were identified via systematic review of the literature. To ensure uniformity of data collection, a quality control process was instituted. Data were retrospectively obtained. RESULTS CONDOR comprises 14 centers in the United States, the United Kingdom, the Netherlands, and Japan that have pooled their data from 1077 dAVF patients seen between 1990 and 2017. The cohort includes 359 patients (33%) with Borden type I dAVFs, 175 (16%) with Borden type II fistulas, and 529 (49%) with Borden type III fistulas. Overall, 852 patients (79%) presented with fistula-related symptoms: 427 (40%) presented with nonaggressive symptoms such as tinnitus or orbital phenomena, 258 (24%) presented with intracranial hemorrhage, and 167 (16%) presented with nonhemorrhagic neurological deficits. A smaller proportion (224 patients, 21%), whose dAVFs were discovered incidentally, were asymptomatic. Many patients (85%, 911/1077) underwent treatment via endovascular embolization (55%, 587/1077), surgery (10%, 103/1077), radiosurgery (3%, 36/1077), or multimodal therapy (17%, 184/1077). The overall angiographic cure rate was 83% (758/911 treated), and treatment-related permanent neurological morbidity was 2% (27/1467 total procedures). The median time from diagnosis to follow-up was 380 days (IQR 120–1038.5 days). CONCLUSIONS With more than 1000 patients, the CONDOR registry represents the largest registry of cranial dAVF patient data in the world. These unique, well-annotated data will enable multiple future analyses to be performed to better understand dAVFs and their management.

OBJECTIVE Current evidence suggests that intracranial dural arteriovenous fistulas (dAVFs) without cortical venous drainage (CVD) have a benign clinical course. However, no large study has evaluated the safety and efficacy of current treatments and their impact over the natural history of dAVFs without CVD. METHODS The authors conducted an analysis of the retrospectively collected multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database. Patient demographics and presenting symptoms, angiographic features of the dAVFs, and treatment outcomes of patients with Borden type I dAVFs were reviewed. Clinical and radiological follow-up information was assessed to determine rates of new intracranial hemorrhage (ICH) or nonhemorrhagic neurological deficit (NHND), worsening of venous hyperdynamic symptoms (VHSs), angiographic recurrence, and progression or spontaneous regression of dAVFs over time. RESULTS A total of 342 patients/Borden type I dAVFs were identified. The mean patient age was 58.1 ± 15.6 years, and 62% were women. The mean follow-up time was 37.7 ± 54.3 months. Of 230 (67.3%) treated dAVFs, 178 (77%) underwent mainly endovascular embolization, 11 (4.7%) radiosurgery alone, and 4 (1.7%) open surgery as the primary modality. After the first embolization, most dAVFs (47.2%) achieved only partial reduction in early venous filling. Multiple complementary interventions increased complete obliteration rates from 37.9% after first embolization to 46.7% after two or more embolizations, and 55.2% after combined radiosurgery and open surgery. Immediate postprocedural complications occurred in 35 dAVFs (15.2%) and 6 (2.6%) with permanent sequelae. Of 127 completely obliterated dAVFs by any therapeutic modality, 2 (1.6%) showed angiographic recurrence/recanalization at a mean of 34.2 months after treatment. Progression to Borden-Shucart type II or III was documented in 2.2% of patients and subsequent development of a new dAVF in 1.6%. Partial spontaneous regression was found in 22 (21.4%) of 103 nontreated dAVFs. Multivariate Cox regression analysis demonstrated that older age, NHND, or severe venous-hyperdynamic symptoms at presentation and infratentorial location were associated with worse prognosis. Kaplan-Meier curves showed no significant difference for stable/improved symptoms survival probability in treated versus nontreated dAVFs. However, estimated survival times showed better trends for treated dAVFs compared with nontreated dAVFs (288.1 months vs 151.1 months, log-rank p = 0.28). This difference was statistically significant for treated dAVFs with 100% occlusion (394 months, log-rank p < 0.001). CONCLUSIONS Current therapeutic modalities for management of dAVFs without CVD may provide better symptom control when complete angiographic occlusion is achieved.

Background Pituitary apoplexy is defined as a sudden neurologic deficit owing to infarction or hemorrhage within the pituitary gland. We report a rare case of apoplexy manifesting with cerebral infarction due to direct compression of the internal carotid artery (ICA) and review the literature. Case Description A 31-year-old man presented with sudden-onset headache, right hemiparesis, decreased left monocular visual acuity, and a nasal visual field deficit of the left eye. Computed tomography angiography revealed evidence of a hyperdense sellar/suprasellar mass with stenosis of the cavernous and supraclinoid segments of the ICAs bilaterally. Magnetic resonance angiography performed the following day showed complete occlusion of the left cervical ICA and cystic changes of the sellar and suprasellar mass suggestive of pituitary hemorrhage. The patient underwent urgent endoscopic endonasal decompression of the mass, and postoperative digital subtraction angiography demonstrated restored flow within the left cervical ICA. Conclusions Of 29 previously published cases of cerebral infarction due to pituitary apoplexy, the majority of cases were related to direct ICA compression. Vascular compression is associated with a high rate of mortality (24%) and should be treated urgently by surgical decompression in cases of severe or progressive neurologic symptoms.

BackgroundMany neurointerventionalists have transitioned to transradial access (TRA) as the preferred approach for neurointerventions as studies continue to demonstrate fewer access site complications than transfemoral access. However, radial artery spasm (RAS) remains one of the most commonly cited reasons for access site conversions. We discuss the benefits, techniques, and indications for using the long radial sheath in RAS and present our experience after implementing a protocol for routine use.MethodsA retrospective review of all patients undergoing neurointerventions via TRA at our institution from July 2018 to April 2020 was performed. In November 2019, we implemented a long radial sheath protocol to address RAS. Patient demographics, RAS rates, radial artery diameter, and access site conversions were compared before and after the introduction of the protocol.Results747 diagnostic cerebral angiograms and neurointerventional procedures in which TRA was attempted as the primary access site were identified; 247 were performed after the introduction of the long radial sheath protocol. No significant differences in age, gender, procedure type, sheath sizes, and radial artery diameter were seen between the two cohorts. Radial anomalies and small radial diameters were more frequently seen in patients with RAS. Patients with clinically significant RAS more often required access site conversion (pConclusionIn our experience, we have found that the use of long radial sheaths significantly reduces the need for access site conversions in patients with RAS during cerebral angiography and neurointerventions.

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare benign lesions that can arise anywhere within the central nervous system. The etiology of these lesions remains unknown and diagnosis is made on pathohistological analysis. We present the case of a 35-year-old male patient with a history of epilepsy since childhood who was evaluated for refractory seizures. MRI revealed a small lesion in the left-posterior temporal lobe suspected to be a cavernoma. A gross total resection of the lesion was achieved via a left temporal craniotomy and pathological analysis revealed CAPNON. At 6 months follow-up, the patient remained neurologically intact and his seizures had ceased.

Background Transradial access (TRA) has recently gained traction as the preferred approach in a variety of neurointerventions after studies have demonstrated equivalent outcomes with fewer complications than transfemoral access (TFA). However, multiple access sites are occasionally necessary when simultaneous selective catheterization of 2 vessels is required. We present the first cases detailing bilateral TRA for complex posterior circulation interventions. Case Descriptions All neuroendovascular cases in which bilateral TRA was obtained at the University of Miami/Jackson Health System were reviewed. Two patients, each with complex left vertebral artery aneurysms, were identified. In each case, bilateral TRA was chosen because 1) left vertebral artery catheterization via right TRA can be technically challenging; 2) simultaneous catheterization of both vertebral arteries was felt to be necessary; 3) prior angiograms had demonstrated that the subclavian arteries would provide the most direct, anatomically feasible access route; and 4) the primary surgeon preferred to avoid TFA. Right TRA and left distal transradial access via the anatomic snuffbox were obtained in both cases to allow both arms to sit on the operator side of the table. Neither patient experienced any perioperative complications. Conclusions Bilateral TRA can be an effective method for catheterizing both vertebral arteries during complex posterior circulation interventions and obviates the need for TFA when multiple arterial access sites are required. Furthermore, distal transradial access allows the left hand to remain more anatomically neutral while being positioned on the right side of the table so that both access sites remain ergonomically favorable for the interventionalist.

OBJECTIVEUntreated hydrocephalus poses a significant health risk to children in the developing world. In response to this risk, global neurosurgical efforts have increasingly focused on endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) in the management of infantile hydrocephalus in low- and middle-income countries (LMICs). Here, the authors report their experience with ETV/CPC at the Hospital Bernard-Mevs/Project Medishare (HBMPM) in Port-au-Prince, Haiti.METHODSThe authors conducted a retrospective review of a series of consecutive children who had undergone ETV/CPC for hydrocephalus over a 1-year period at HBMPM. The primary outcome of interest was time to ETV/CPC failure. Univariate and multivariate analyses using a Cox proportional hazards regression were performed to identify preoperative factors that were associated with outcomes.RESULTSOf the 82 children who underwent ETV/CPC, 52.2% remained shunt free at the last follow-up (mean 6.4 months). On univariate analysis, the ETV success score (ETVSS; p = 0.002), success of the attempted ETV (p = 0.018), and bilateral CPC (p = 0.045) were associated with shunt freedom. In the multivariate models, a lower ETVSS was independently associated with a poor outcome (HR 0.072, 95% CI 0.016–0.32, p < 0.001). Two children (2.4%) died of postoperative seizures.CONCLUSIONSAs in other LMICs, ETV/CPC is an effective treatment for hydrocephalus in children in Haiti, with a low but significant risk profile. Larger multinational prospective databases may further elucidate the ideal candidate for ETV/CPC in resource-poor settings.

BackgroundThe transradial approach (TRA) has gained increasing popularity for neuroendovascular procedures. However, the experience with TRA in neuroangiography is still in early stages in most centers, and the safety and feasibility of this approach have not been well established. The purpose of this study is to report the safety and feasibility of TRA for neuroendovascular procedures.MethodsWe reviewed charts from six institutions in the USA to include consecutive patients who underwent diagnostic or interventional neuroendovascular procedures through TRA from July 2018 to July 2019. Collected data included baseline characteristics, procedural variables, complications, and whether there was a crossover to transfemoral access.ResultsA total of 2203 patients were included in the study (age 56.1±15.2, 60.8% women). Of these, 1697 (77%) patients underwent diagnostic procedures and 506 (23%) underwent interventional procedures. Successfully completed procedures included aneurysm coiling (n=97), flow diversion (n=89), stent-assisted coiling (n=57), balloon-assisted coiling (n=19), and stroke thrombectomy (n=76). Crossover to femoral access was required in 114 (5.2%). There were no major complications related to the radial access site. Minor complications related to access site were seen in 14 (0.6%) patients.ConclusionIn this early stage of transforming to the ‘radial-first’ approach for neuroendovascular procedures, TRA was safe with low complication rates for both diagnostic and interventional procedures. A wide range of procedures were completed successfully using TRA.

Background and Purpose: Since the publication of ARUBA trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformations), outcomes in treated and untreated patients with unruptured arteriovenous malformation have been thoroughly compared. However, no prior analysis of ARUBA patients has sought to identify risk factors for perioperative stroke. Improved understanding of risks within the ARUBA cohort will help clinicians apply the study’s findings in a broader context. Methods: The National Institute of Neurological Disorders and Stroke database was queried for all data relating to ARUBA patients, including demographics, interventions undertaken, and timing of stroke. Retrospective cohort analysis was performed with the primary outcome of perioperative stroke in patients who underwent endovascular intervention, and stroke risk was modeled with multivariate analysis. Results: A total of 64 ARUBA patients were included in the analysis. One hundred and fifty-ninth interventions were performed, and 26 (16%) procedures resulted in stroke within 48 hours of treatment. Posterior cerebral artery supply (adjusted odds ratio, 4.42 [95% CI, 1.23–15.9], P =0.02) and Spetzler-Martin grades 2 and 3 arteriovenous malformation (adjusted odds ratio, 7.76 [95% CI, 1.20–50.3], P =0.03; 9.64 [95% CI, 1.36–68.4], P =0.04, respectively) were associated with increased perioperative stroke risk in patients who underwent endovascular intervention. Patients treated in the United States or Germany had a significantly lower stroke risk than patients treated in other countries (adjusted odds ratio, 0.18 [95% CI, 0.04–0.82], P =0.02). Conclusions: Knowing patient and lesion characteristics that increase risk during endovascular treatment can better guide clinicians managing unruptured brain arteriovenous malformation. Our analysis suggests risk of perioperative stroke is dependent on Spetzler-Martin grade and posterior-circulation arterial supply. Differences in regional treatment paradigms may also affect stroke risk.

Background and Purpose: Epidemiological studies have shown racial and ethnic minorities to have higher stroke risk and worse outcomes than non-Hispanic Whites. In this cohort study, we analyzed the STAR (Stroke Thrombectomy and Aneurysm Registry) database, a multi-institutional database of patients who underwent mechanical thrombectomy for acute large vessel occlusion stroke to determine the relationship between mechanical thrombectomy outcomes and race. Methods: Patients who underwent mechanical thrombectomy between January 2017 and May 2020 were analyzed. Data included baseline characteristics, vascular risk factors, complications, and long-term outcomes. Functional outcomes were assessed with respect to Hispanic status delineated as non-Hispanic White (NHW), non-Hispanic Black (NHB), or Hispanic patients. Multivariate analysis was performed to identify variables associated with unfavorable outcome or modified Rankin Scale ≥3 at 90 days. Results: Records of 2115 patients from the registry were analyzed. Median age of Hispanic patients undergoing mechanical thrombectomy was 60 years (72–84), compared with 63 years (54–74) for NHB, and 71 years (60–80) for NHW patients ( P P P P Conclusions: Hispanic patients are less likely to have favorable outcome at 90 days following mechanical thrombectomy compared to NHW or NHB patients. Further prospective studies are required to validate our findings.

Fusiform middle cerebral artery (MCA) aneurysms that require treatment can often necessitate complex endovascular or microsurgical treatment. We present a case of a 25-yr-old female with an incidentally discovered left 14-mm fusiform MCA aneurysm incorporating the frontal MCA trunk origin in its dome. The location and anatomy were not favorable for endovascular treatment with flow diversion. The patient was offered continued observation or microsurgical treatment. Direct clipping of this aneurysm was not possible. After a thorough discussion of the risks, benefits, indications, and natural history of the lesion, the patient desired to have the aneurysm treated given her young age, location, size of the aneurysm, and the significant clinical experience of the treating team in bypass surgery. The patient underwent superficial temporal artery to frontal M2 (STA-FM2) direct bypass for flow replacement followed by microsurgical trapping and clip ligation. The patient was maintained on antiplatelet therapy preoperatively and postoperatively. The patient had a transient aphasia and mild right upper extremity weakness (4/5) in the immediate postoperative period, which fully recovered by the time of patient discharge. The case presentation, surgical anatomy, technique, and postoperative course and outcome are reviewed. The different strategies for bypass and clip ligation are reviewed with particular focus on the anatomic constraints for each bypass configuration. The outcomes of bypass surgery for MCA aneurysms are reviewed.1-7 The patient gave verbal consent for participating in the procedure, surgical video, and publication of their image.

The radial access route has significantly lower complications compared to the femoral access route. Often users have become used to the femoral approach and its attendant complications but it is worth reviewing that despite its minimally invasive nature as opposed to open craniotomy, endovascular transfemoral access is certainly not without risk. These risks include life threatening retroperiotenal hematoma formation and local hematoma formation as well as limb threatening occlusion of the femoral artery, which is an end artery thus must be urgently revascularlized in the event of compromise. The complications of femoral access are reviewed as well as strategies for management.

Over 20 years of investigation and experience have gone into pioneering the radial approach for cardiac interventions. This has shown the technique to be superior to the traditional transfemoral technique for a variety of reasons. Neurointerventionalists have until recently been unaware of this innovation and are only starting to use it in their practice. Most of the data from the interventional cardiology journey into radial access is unknown to the neurointerventionalist audience, and concepts that underpin radial access are unfamailiar. Even basic concepts such as radial arterial anatomy, collateral circulation of the hand, and low rates of ischemic complications have been siloed in the cardiology literature. The core rationale for the transradial approach is reviewed.

IntroductionTransradial access is increasingly used among neurointerventionalists as an alternative to the transfemoral route. Currently available data, building on the interventional cardiology experience, primarily focus on right radial access. However, there are clinical scenarios when left-sided access may be indicated. The purpose of this study was to evaluate the technical feasibility of left transradial access to cerebral angiography across three institutions.MethodsA retrospective chart review was performed for patients who underwent cerebral angiography accessed via the left radial artery at three institutions between January 2018 and July 2019. The outcome variables studied were successful catheterization, vascular complications, and fluoroscopic time.ResultsNineteen patients underwent a total of 25 cerebral angiograms via left transradial access for cerebral aneurysms (n=15), basilar occlusion (n=1), carotid stenosis (n=1), arteriovenous malformation (n=1), and cervical neurofibroma (n=1). There were 12 diagnostic angiograms and 13 interventional angiograms. The left transradial approach was chosen due to left vertebrobasilar pathology (n=22), right subclavian stenosis (n=2), and previous right arm amputation (n=1). There was one instance of radial artery spasm, which resolved after catheter removal, and one conversion to transfemoral access in an interventional case due to lack of distal catheter support. There were no procedural complications.ConclusionsLeft transradial access in diagnostic and interventional cerebral angiography is a technically feasible, safe, and an effective alternative when indicated, and may be preferable for situations in which pathology locations or anatomic limitations preclude right-sided radial access.

BackgroundNumerous large randomized trials have shown a significant morbidity and mortality benefit with the transradial approach (TRA) over the transfemoral approach (TFA) for endovascular procedures. However, this technique is routinely avoided or aborted due to unfamiliarity with the technique and the associated anatomical difficulties that may be faced in this approach. The objective of this review is to identify both the common and uncommon challenges that may be encountered during a transradial approach for cerebrovascular catheterization and to provide tips and tricks to overcome the transradial learning curve.MethodA careful review of the literature and of all our transradial cases was carried out to identify the common challenges and complications that are encountered when using TRA for diagnostic cerebral angiography and neurointerventions.ResultsA stepwise approach is provided to prevent and manage common challenges including radial artery access failure, radial artery spasm, radial artery anomalies and tortuosity, radial artery occlusion, radial artery perforation and hematoma, subclavian tortuosity and anomalies, and catheter knots and kinks.ConclusionThe ability to recognize and navigate anatomical variations and complications unique to TRA will accelerate learning, decrease unnecessary morbidity and mortality, and further advance the neurovascular field.

Background Intracranial pseudoaneurysms (PSAs) are associated with high rupture and mortality rates and have traditionally been treated by parent vessel sacrifice. There has been recent interest in using flow-diverting devices for treatment of these complex lesions while preserving flow through the parent artery. The objective of this study is to examine the safety and efficacy of these devices in the treatment of intracranial PSA. Methods We performed a multi-institutional retrospective study of intracranial PSAs treated with the Pipeline Embolization Device (PED) between 2014 and 2017 at 7 institutions. Complications and clinical and radiographic outcomes were reviewed. Results A total of 19 patients underwent PED placement for intracranial PSA. Iatrogenic injury and trauma comprised most etiologies in our series. The mean pseudoaneurysm diameter was 8.8 mm, and 18 of 19 PSAs (95%) involved the internal carotid artery (ICA). Multiple PEDs were deployed in a telescoping fashion in 7 patients (37%). Of the 18 patients with follow up imaging, 14 (78%) achieved complete pseudoaneurysm obliteration and 2 achieved near-complete obliteration (11%). Two patients (11%) were found to have significant pseudoaneurysm progression on short-term follow-up and required ICA sacrifice. No patients experienced new neurologic deficits or deterioration secondary to PED placement. No patients experienced bleeding or rebleeding from PSA. Conclusions In well-selected patients, the use of flow-diverting stents may be a feasible alternative to parent vessel sacrifice. Given the high morbidity and mortality associated with PSA, we recommend short- and long-term radiographic follow-up for patients treated with flow-diverting stents.

Objective: Mechanical thrombectomy is the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke (AIS) up to 6 h after onset. Recent trials have demonstrated a benefit for wake-up strokes and patients beyond 6 h. Methods: A systematic literature review was conducted for multicenter randomized clinical trials (RCTs) investigating endovascular stroke treatment using perfusion imaging to identify patients that may benefit from mechanical thrombectomy for AIS beyond 6 h of onset. Random effects meta-analysis was used to analyze the following outcomes: 90-day functional independence rates with modified Rankin Scale (mRS ≤2), 90-day mortality, and symptomatic intracranial hemorrhage (sICH) rates. Further stratification was carried out by age and presentation. Results: Two multicenter RCT’s were included as follows: DAWN and DEFUSE-3. Pooled 90-day functional independence rates favored endovascular management (odds ratio [OR] 5.01; P < 0.00001). Subgroup analysis demonstrated continued 90-day functional independence benefit for endovascular management regardless of age (≥80 years, OR 5.65, P = 0.01; ≤80 years, OR 4.92, P < 0.00001). When stratified for the manner of stroke discovery, 90-day functional independence rates favored endovascular management for wake-up strokes (OR 8.74, P < 0.00001) and known-time onset strokes (OR 5.08, 95% confidence interval [CI] 2.04–12.65, P = 0.0005), although no benefit was observed for unwitnessed strokes (OR 1.64, 95% CI 0.17–16.04, P = 0.67). No difference observed in 90-day mortality rates (OR 0.71; P = 0.14) or in SICH rates (OR 1.67; P = 0.29). Conclusions: This meta-analysis reinforces that endovascular management is superior to standard medical management alone for the treatment of AIS due to LVO beyond 6 h of onset in patients with perfusion-imaging selection.

Background The distal transradial approach (dTRA) is being widely adopted by interventional cardiologists, primarily owing to reduced morbidity and mortality from access site complications. The distal radial artery has advantages over standard radial access in relation to procedural positioning and radial artery preservation, particularly in patients who may require multiple angiograms. One disadvantage is the smaller diameter of the artery with more challenging puncture of a smaller, weaker artery. We demonstrate the feasibility of dTRA in 2 patients who underwent successful diagnostic angiography and mechanical thrombectomy. Case Description Two patients underwent dTRA for neurointerventions. In patient 1, a 5-F Glidesheath Slender and a Sim2 catheter were used for a 6-vessel cerebral angiogram. In patient 2, an 0.88-inch sheathless guide catheter was used to perform a mechanical thrombectomy. Successful hemostasis in both cases was achieved with a Safeguard Radial Compression Device; no complications were observed. Conclusions Neurovascular access via dTRA is feasible, and further exploration is warranted.

BackgroundThe transradial approach (TRA) to endovascular procedures decreases access site morbidity and mortality in comparison with the traditional transfemoral technique (TFA). Despite its improved safety profile, there is a concern that TRA is less favorable for neurointerventional procedures that require large coaxial systems to manage the small tortuous cerebral vessels.ObjectiveTo report our experience with TRA for flow diverter placement for treatment of unruptured cerebral aneurysms.MethodsWe performed a retrospective review of prospective institutional databases at two high-volume centers to identify 49 patients who underwent flow diversion for aneurysm treatment via primary TRA between November 2016 and November 2018. Patient demographics, procedural techniques, and clinical data were recorded.ResultsOf the 49 patients, 39 underwent successful flow diversion placement by TRA. Ten patients were converted to TFA after attempted TRA. There were no procedural complications. Reasons for failure included tortuosity in eight patients and severe radial artery spasm in two.ConclusionsIn the largest reported series to date of flow diverter deployment via TRA for aneurysm treatment, we demonstrate the technical feasibility and safety of the method. The most common reason for failure of TRA was an acute angle of left common carotid artery origin or left internal carotid artery tortuosity. Overall, our data suggest that increasing adoption of TRA is merited given its apparent equivalence to the current TFA technique and its documented reduction in access site complications.

Background Reperfusion time influences patient outcome in mechanical thrombectomy for large vessel occlusion. We analyzed anatomic features that could be used to make preoperative and intraoperative decisions to minimize revascularization time. Methods We reviewed a prospectively maintained database for patients with stroke evaluated from February 2015 to July 2016. Patients received a score based on bovine arch, aortic arch, and internal carotid artery dolichoarteriopathy (B.A.D. score), which we correlated with procedural times and outcomes. Univariate analysis was performed to identify predictors of procedural times, revascularization, complications, and outcome. Relevant variables were assessed via multivariate regression. Results We identified 61 patients (31 men) who underwent transfemoral thrombectomy. Mean puncture to reperfusion time was 46 minutes. Age >75 years (odds ratio [OR] = 3.98; 95% confidence interval [CI], 1.17–13.54; P = 0.027) and high B.A.D. score (OR = 2.55; 95% CI, 1.17–5.57; P = 0.019) were significant predictors of puncture to reperfusion time >40 minutes. Mean puncture to first-pass time was 24 ± 14.2 minutes. Age >65 years (OR = 4.68; 95% CI, 1.07–20.55; P = 0.041) and high B.A.D. score (OR = 2.84; 95% CI, 1.18–6.85; P = 0.020) were independently predictive of time to first pass >20 minutes. Lower scores predicted higher Thrombolysis In Cerebral Infarction score (OR = 0.07; 95% CI, 0.01–0.81; P = 0.033). Higher scores predicted hemorrhagic transformation (OR = 4.8; 95% CI, 1.19–12.29; P = 0.024) and modified Rankin Scale score >4 (OR = 3.0; 95% CI, 1.15–7.92; P = 0.025) after thrombectomy. Conclusions Bovine variation, aortic arch type, and internal carotid artery dolichoarteriopathy are associated with increased revascularization time and poor outcomes in thrombectomy. We developed the B.A.D. score to predict reperfusion time and outcomes, demonstrating need for preoperative anatomic evaluation to guide treatment.

Background Dural arteriovenous fistulas (DAVFs) are pathologic vascular connections that shunt dural arterial flow directly to dural venous drainage. Only a few isolated case reports describe syncope on presentation. We report the first case of DAVF causing recurrent, progressive syncope in an otherwise asymptomatic patient. Case report A female in her late 20s presented with a 9-year history of syncopal episodes and was found to have a DAVF. Syncopal episodes were exacerbated by positional changes, strenuous activity and emotional stressors. Symptoms occurred upon wakening and lasted for 2 to 3 hours before she was able to regain functionality. Physical examination revealed no abnormalities. Magnetic resonance imaging of the brain showed no irregularities. Magnetic resonance angiography revealed abnormal serpiginous structures in the left jugular foramen which communicated with the ascending pharyngeal branch of the left external carotid artery. Cerebral angiogram disclosed a left jugular bulb DAVF supplied by the left ascending pharyngeal and left occipital arteries. The DAVF was successfully managed by progressive endovascular embolization with coils and Onyx 34. On clinical follow-up evaluation, the patient had no further episodes of dizziness or syncope. Conclusion We present an atypical case of DAVF in a patient presenting with recurrent syncope. Only 4 cases of DAVF causing syncope have been reported, all in combination with other neurological symptoms. In comparison, we report a unique case of DAVF presenting solely with recurrent syncope, a previously undocumented finding in the literature. Our case adds to other reports of nonspecific DAVF presentations and highlights the importance of considering this etiology.

Introduction: Previous studies have reported that Hispanic stroke patients have limited access to mechanical thrombectomy (MT) compared to other ethnic groups. This has resulted in worse stroke outcomes in this group. However, limited data is available about the outcomes of MT in Hispanic patients. Methods: We used data from the Stroke Thrombectomy and Aneurysm Registry (STAR) that combined the prospectively maintained databases of 28 thrombectomy-capable stroke centers in the US, Europe, and Asia. Consecutive patients who underwent MT were included in these analyses and patients were divided into 2 groups (Hispanics vs. non-Hispanics). Baseline features, time from symptom onset, thrombolysis receipt, final thrombolysis in cerebral infarction (TICI) score, symptomatic hemorrhage, and 90-day functional outcomes (measured by modified Rankin scale-mRS) were compared between Hispanic and non-Hispanics patients. A generalized linear model with logit link was used to assess the relationship between ethnicity and favorable outcomes at 90-day (mRS 0-2) controlling for confounders. Results: We included 2015 patients in these analyses. Of those, 285 (14.1%) were Hispanic. As shown in table 1, Hispanic patients were older (72 vs. 70, p=0.007), more likely to have diabetes (41.1% vs. 26.5%, p Conclusion: Hispanic patients receiving MT have higher rate of stroke risk factors including diabetes and hypertension. Moreover, Hispanic ethnicity was independently associated with lower probability of favorable 90-day outcome.

BackgroundAlthough the liquid embolic agent, Onyx, is often the preferred embolic treatment for cerebral dural arteriovenous fistulas (DAVFs), there have only been a limited number of single-center studies to evaluate its performance.ObjectiveTo carry out a multicenter study to determine the predictors of complications, obliteration, and functional outcomes associated with primary Onyx embolization of DAVFs.MethodsFrom the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database, we identified patients who were treated for DAVF with Onyx-only embolization as the primary treatment between 2000 and 2013. Obliteration rate after initial embolization was determined based on the final angiographic run. Factors predictive of complete obliteration, complications, and functional independence were evaluated with multivariate logistic regression models.ResultsA total 146 patients with DAVFs were primarily embolized with Onyx. Mean follow-up was 29 months (range 0–129 months). Complete obliteration was achieved in 80 (55%) patients after initial embolization. Major cerebral complications occurred in six patients (4.1%). At last follow-up, 84% patients were functionally independent. Presence of flow symptoms, age over 65, presence of an occipital artery feeder, and preprocedural home anticoagulation use were predictive of non-obliteration. The transverse-sigmoid sinus junction location was associated with fewer complications, whereas the tentorial location was predictive of poor functional outcomes.ConclusionsIn this multicenter study, we report satisfactory performance of Onyx as a primary DAVF embolic agent. The tentorium remains a more challenging location for DAVF embolization, whereas DAVFs located at the transverse-sigmoid sinus junction are associated with fewer complications.

The inflammatory response appears to play a critical role in clotting in which neutrophil extracellular traps (NETs) are the major drivers of thrombosis in acute ischemic stroke (AIS). The inflammasome is an innate immune complex involved in the activation of interleukin (IL)-18 and IL-1β through caspase-1, but whether the inflammasome plays a role in NETosis in AIS remains poorly understood. Here we assessed the levels of inflammasome signaling proteins in NETs and their association with clinical and procedural outcomes of mechanical thrombectomy for AIS. Electron microscopy and immunofluorescence indicate the presence of NETs in thrombi of patients with AIS. Moreover, the inflammasome signaling proteins caspase-1 and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) were also present in clots associated with the marker of NETosis citrullinated histone 3H (CitH3). Analysis of protein levels by a simple plex assay show that caspase-1, ASC and interleukin (IL)-1β were significantly elevated in clots when compared to plasma of AIS patients and healthy controls, while IL-18 levels were lower. Moreover, multivariate analyses show that IL-1β levels in clots contribute to the number of passes to achieve complete recanalization, and that ASC, caspase-1 and IL-18 are significant contributors to time to recanalization. Thus, inflammasome proteins are elevated in NETs present in thrombi of patients with AIS that contribute to poor outcomes following stroke.

Dorsal internal carotid artery (ICA) blister aneurysms are an uncommon aneurysm variant constituting 0.3% to 1% of intracranial aneurysms and can be due to ulceration, atherosclerosis, or dissection.1-3 Despite its rarity, it carries a high risk of rupture with an estimation of 0.9% to 6.5% among intracranial aneurysms.1,2 Blister aneurysms are small in size, have no distinguishable neck, and have a friable wall that can easily rupture if manipulated, hence the difficulty in its treatment utilizing both microsurgical and endovascular techniques.1,2,4-6 Endovascular coiling of these lesions may not be adequate due to the broad-based size; stenting requires the use of antiplatelet medications, which could lead to rebleeding; flow diversion takes longer to exert its treatment effect.1,4 Conversely, microsurgical management carries a higher intraoperative rupture rate.2 Microsurgical options include clipping, clip reconstruction, trapping with bypass, and wrapping.4,7 We present a case of a 38-yr-old man who presented with a ruptured right dorsal ICA blister aneurysm treated with microsurgical trapping with intraoperative flow measurements. We demonstrate how the use of quantitative intraoperative flow measurements allows confident sacrifice of the supraclinoid ICA. We also demonstrate in contrast another case example of utilizing a clip-graft repair. The patient remained unchanged with an intact neurological exam, and postoperative imaging showed no aneurysm remnant and patent anterior choroidal artery. We review the literature and management of dorsal ICA aneurysms.8-15 We also review the technical nuances and different endovascular and microsurgical treatments that can be used for this condition. The patient gave informed consent for the procedure and verbal consent to the publication.

Mechanical thrombectomy has become the standard of care for acute large vessel occlusion ischemic strokes, with time to reperfusion being the critical factor in determining outcomes. Complex aortic arch and carotid arterial anatomy is associated with increased technical difficulty and thus prolonged procedural times and complication rates. In particular for mechanical thrombectomy, patients with complex aortic arch anatomy and ICA tortuosity are associated with significant increases in puncture-to-reperfusion times. Transradial approach (TRA) from the right subclavian artery offers a technically favorable trajectory in folded over arches and tortuosity and is associated with a greater than 60% reduction in vascular complications, overwhelming patient preference, and reduced post-procedure nursing care, hospital stay, and cost when compared to transfemoral approach. In this chapter, we review the TRA technique for mechanical thrombectomy.

BackgroundThe prevalence of women physicians is steadily rising, but the field of neurointervention remains one of the most male-dominated subspecialties in medicine. A fear of radiation exposure, particularly during pregnancy and childbearing years, may be responsible for deterring some of the best and brightest. This is the first study to examine the amount of maternal and fetal radiation exposure during a pregnant neurointerventional fellow’s training.MethodsWe retrospectively analyzed the radiation exposure of a neurointerventional fellow prior to and during pregnancy from February 2018 to May 2019 in 758 neurointerventional cases. The collar dosimeter was used to measure overall maternal exposure and an additional fetal dosimeter was worn under two lead apron skirts to estimate fetal radiation exposure.ResultsThere was not a significant difference between pre- and post-pregnancy overall maternal radiation exposure as measured by the collar dosimeter (151 mrem pre-pregnancy and 105 mrem during pregnancy, p=0.129). Mean fluoroscopy time and fluoroscopy emission per procedure also did not differ prior to and during pregnancy. Fetal radiation exposure measurements from both the Mirion Genesis Ultra TLD dosimeter as well as the Mirion Instadose dosimeters worn under double lead apron skirts were 0 mrem for all 6 months.ConclusionThese findings suggest that, when optimal radiation safety practices are implemented, the fetal dose of a pregnant neurointerventionalist is negligible. Further studies and education are necessary to encourage women to choose neurointervention and allow practicing women neurointerventionalists to maintain their productivity during their reproductive years.

Rotational vertebral artery (VA) occlusion syndrome, also known as bow hunter's syndrome, is an uncommon variant of vertebrobasilar insufficiency typically occurring with head rotation.1-3 The most common presenting symptom is dizziness (76.8%), followed by visual abnormalities and syncope (50.4% and 40.4%, respectively).2 Osteophytic compression due to spinal spondylosis has been shown to be the most common etiology (46.2%), with other factors, such as a fibrous band, muscular compression, or spinal instability, being documented.1,2 Treatment is dependent on the level and site of VA compression with anterior, anterolateral, or posterior approaches being described.1,4 We present the case of a 72-yr-old male with osteophytic compression of the V3 segment of the vertebral artery at the occipital-cervical junction. The patient underwent a C1 hemilaminectomy and removal of osteophytic compression from the occipital-cervical joint. The patient had complete resolution of compression of his vertebral artery on postoperative imaging and remained neurologically intact following the procedure. We review the literature on this topic, the technical nuances of the procedure performed, and review the different treatment modalities available for this rare condition.1-11 The patient consented to the procedure and to publication of their image.

Objective To determine the impact of the 2019 novel coronavirus disease (COVID-19) pandemic on operative case volume in 8 U.S. neurosurgical residency training programs in early 2020 and to survey these programs regarding training activities during this period. Methods A retrospective review was conducted of monthly operative case volumes and types for 8 residency programs for 2019 and January through April 2020. Cases were grouped as elective cranial, elective spine, and nonelective emergent cases. Programs were surveyed regarding residents' perceptions of the impact of COVID-19 on surgical training, didactics, and research participation. Data were analyzed for individual programs and pooled across programs. Results Across programs, the 2019 monthly mean ± SD case volume was 211 ± 82; 2020 mean ± SD case volumes for January, February, March, and April were 228 ± 93, 214 ± 84, 180 ± 73, and 107 ± 45. Compared with 2019, March and April 2020 mean cases declined 15% (P = 0.003) and 49% (P = 0.002), respectively. COVID-19 affected surgical case volume for all programs; 75% reported didactics negatively affected, and 90% reported COVID-19 resulted in increased research time. Several neurosurgery residents required COVID-19 testing; however, to our knowledge, only 1 resident from the participating programs tested positive. Conclusions This study documents a significant reduction in operative volume in 8 neurosurgery residency training programs in early 2020. During this time, neurosurgery residents engaged in online didactics and research-related activities, reporting increased research productivity. Residency programs should collect data to determine the educational impact of the COVID-19 pandemic on residents' operative case volumes, identify deficiencies, and develop plans to mitigate any effects.

The prediction of outcome after mechanical thrombectomy (MT) of basilar artery occlusion (BAO) remains an area of investigation. The objective of this study was to evaluate the prognostic role of presenting National Institute Health of Stroke Scale (NIHSS) scores in predicting favorable 90-day functional outcome. A survey of 7 electronic databases from inception to May 2020 was conducted following PRISMA guidelines. Articles were screened against pre-specified criteria. Multivariate odds ratios (ORs) for favorable 90-day function outcome (modified Rankin Score 0-2) were extracted and pooled by meta-analysis of proportions with random effects modeling. A total of 10 individual studies satisfied criteria for selection and described a total of 941 BAO patients managed by MT. Analysis revealed 590 (63%) males with a mean age of 66.6 years. The median presenting NIHSS was 19, and 316 (34%) patients were reported to have a favorable functional status 90-days after treatment. Lower presenting NIHSS scores independently and significantly predicted favorable 90-day functional outcome in BAO patients with a pooled OR of 0.89 (95% CI, 0.87-0.92; I2 = 18%; P-heterogeneity = 0.28). Meta-regression did not detect any clinical parameter that influenced this trend direction or its significance, and bias assessments were unremarkable. We confirm in this study via a consensus within the literature that the presenting NIHSS score predicts 90-day functional outcome in BAO patients treated by MT. Further, its standardized use allows more meaningful comparisons between interventions and anatomical locations.

Background Traditionally, cervical carotid artery stenting is done through transfemoral or transcarotid approach. However, access site bleeding remains a significant challenge in both techniques, with a rate of about 4% in recent studies. In this study, we explore the feasibility of using transradial approach for cervical carotid stenting as a potential alternative. Methods We collected data from the prospectively maintained registries of 6 centers in the United States to include consecutive patients who underwent carotid stenting for treatment of symptomatic carotid-artery stenosis using transradial approach from October 2018 until June 2019. Collected data included baseline characteristics, procedural variables, whether there was a crossover to transfemoral access, and complications. Our primary outcome was the complication rate related to the access site. Results A total of 19 patients were included in this study. Mean age was 68.6 (±8), and 5 (26.3%) were females. The right radial artery access was used in all cases. Stenting of the right cervical internal carotid artery was done in 15 (78.9%) of the cases. Regarding the antispasmodic regimen used, Verapamil was used in 2 cases, Nitroglycerin was used in 6 cases, and a combination of both was used in 11 cases. Between 2000–5000 units of heparin were administered intraarterially or intravenously immediately after obtaining the access. A 6-French sheath was used in 13 cases, a 7-French sheath in 3 cases, and in 3 cases, the guide catheter (AXS Infinity, Stryker, USA) was exchanged over a 7-French sheath. Regarding guide catheters used, Benchmark (Penumbra, USA) was used in 14 cases, AXS Infinity in 3 cases, and Envoy (Codman Neuro, USA) in 2 cases. Mean contrast dose required was 93.3 (±48.4), radiation exposure was 14603 (±26118) mGy, and procedure duration was 24.6 (±14.2) min. None of the included patients had a complication related to access site, and only one patient required a crossover to transfemoral approach because of a device-related complication. Conclusion Transradial approach is a feasible and safe option for cervical carotid stenting. The complication rate in our study is lower than previously reported numbers for transfemoral and transcarotid carotid stenting, but larger-scale studies are needed to confirm our findings. Disclosures E. Almallouhi: None. S. Al kasab: None. P. Jabbour: 2; C; Medtronic and MicroVention. M. Gooch: None. A. Sweid: None. N. Chalouhi: None. S. Chen: None. Y. Li: None. E. Peterson: None. D. Yavagal: 2; C; Medtronic Neurovascular, Cerenovus, Rapid Medical and Neuralanalytics. R. Starke: 2; C; Penumbra, Abbott, Medtronic, InNeuroCo and Cerenovus. A. Spiotta: 1; C; Penumbra. 2; C; Penumbra, Stryker, Cerenovus, Terumo.

OBJECTIVE The risk-to-benefit profile of treating an unruptured high-grade dural arteriovenous fistula (dAVF) is not clearly defined. The aim of this multicenter retrospective cohort study was to compare the outcomes of different interventions with observation for unruptured high-grade dAVFs. METHODS The authors retrospectively reviewed dAVF patients from 12 institutions participating in the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR). Patients with unruptured high-grade (Borden type II or III) dAVFs were included and categorized into four groups (observation, embolization, surgery, and stereotactic radiosurgery [SRS]) based on the initial management. The primary outcome was defined as the modified Rankin Scale (mRS) score at final follow-up. Secondary outcomes were good outcome (mRS scores 0–2) at final follow-up, symptomatic improvement, all-cause mortality, and dAVF obliteration. The outcomes of each intervention group were compared against those of the observation group as a reference, with adjustment for differences in baseline characteristics. RESULTS The study included 415 dAVF patients, accounting for 29, 324, 43, and 19 in the observation, embolization, surgery, and SRS groups, respectively. The mean radiological and clinical follow-up durations were 21 and 25 months, respectively. Functional outcomes were similar for embolization, surgery, and SRS compared with observation. With observation as a reference, obliteration rates were higher after embolization (adjusted OR [aOR] 7.147, p = 0.010) and surgery (aOR 33.803, p < 0.001) and all-cause mortality was lower after embolization (imputed, aOR 0.171, p = 0.040). Hemorrhage rates per 1000 patient-years were 101 for observation versus 9, 22, and 0 for embolization (p = 0.022), surgery (p = 0.245), and SRS (p = 0.077), respectively. Nonhemorrhagic neurological deficit rates were similar between each intervention group versus observation. CONCLUSIONS Embolization and surgery for unruptured high-grade dAVFs afforded a greater likelihood of obliteration than did observation. Embolization also reduced the risk of death and dAVF-associated hemorrhage compared with conservative management over a modest follow-up period. These findings support embolization as the first-line treatment of choice for appropriately selected unruptured Borden type II and III dAVFs.

Obesity is an established risk factor for the development of acute ischemic stroke. However, its effect on clinical outcomes after acute ischemic stroke has remained controversial. In the present study, we evaluated the association of body mass index (BMI) on outcomes after mechanical thrombectomy (MT) for large vessel occlusion acute ischemic stroke (LVOS).We reviewed our prospective endovascular database for patients who had undergone MT for LVOS from 2015 to 2018. The BMI was analyzed as a continuous and categorical variable, with the latter defined as BMI,18.5 kg/mA total of 335 patients had undergone MT, with 7 (2.1%) classified as underweight, 107 (31.9%) normal, 141 (42.1%) overweight, and 80 (23.9%) obese. The procedural times, techniques, and reperfusion success (treatment in cerebral infarction score2b) were not significantly different among the BMI categories. A significant inverse linear correlation was found between the BMI and symptomatic hemorrhagic. For patients with successful reperfusion (treatment in cerebral infarction score2b), we also found a significant bell-shaped relationship between the BMI and functional independence (modified Rankin scale score3), with high and low BMIs associated with worse outcomes. For patients without post-MT symptomatic hemorrhage, a significant linear correlation was found between BMI and inpatient mortality.For LVOS patients treated with MT, a high BMI will not affect procedural success. However, it was independently associated with lower rates of functional independence in recanalized patients. Thus, the obesity paradox does not appear to pertain to MT, although larger prospective studies are necessary.

A carotid-cavernous fistula (CCF) is an abnormal connection between the arteries and veins of the cavernous sinus. Iatrogenic CCFs have been described as potential complications following aneurysm coiling, balloon angioplasty, and transsphenoidal surgery. In this case report, we describe a rare case of an iatrogenic direct CCF following mechanical thrombectomy (MT) for acute ischemic stroke. A 78-year-old female presented to an outside hospital with a new onset of right-sided weakness and aphasia and underwent emergency MT for a left middle cerebral artery (MCA) occlusion. The procedure was complicated by iatrogenic injury to the left cavernous internal carotid artery (ICA), which resulted in a direct high-flow CCF. The patient was transferred to our hospital and the fistula was closed with transarterial coils. Ten days later, she returned with diplopia and cranial nerve VI palsy due to residual pseudoaneurysm and was treated with a flow-diverting stent. On follow-up, the patient was neurologically intact and imaging showed no residual fistula. As the frequency of MTs performed for acute ischemic stroke continues to rise, neurointerventionalists should be aware of this potential rare complication and be prepared to manage patients who develop symptomatic CCF.

BackgroundCurrently, there are no large-scale studies in the neurointerventional literature comparing safety between transradial (TRA) and transfemoral (TFA) approaches for flow diversion procedures. This study aims to assess complication rates in a large multicenter registry for TRA versus TFA flow diversion.MethodsWe retrospectively analyzed flow diversion cases for cerebral aneurysms from 14 institutions from 2010 to 2019. Pooled analysis of proportions was calculated using weighted analysis with 95% CI to account for results from multiple centers. Access site complication rate and overall complication rate were compared between the two approaches.ResultsA total of 2,285 patients who underwent flow diversion were analyzed, with 134 (5.86%) treated with TRA and 2151 (94.14%) via TFA. The two groups shared similar patient and aneurysm characteristics. Crossover from TRA to TFA was documented in 12 (8.63%) patients. There were no access site complications in the TRA group. There was a significantly higher access site complication rate in the TFA cohort as compared with TRA (2.48%, 95% CI 2.40% to 2.57%, vs 0%; p=0.039). One death resulted from a femoral access site complication. The overall complications rate was also higher in the TFA group (9.02%, 95% CI 8.15% to 9.89%) compared with the TRA group (3.73%, 95% CI 3.13% to 4.28%; p=0.035).ConclusionTRA may be a safer approach for flow diversion to treat cerebral aneurysms at a wide range of locations. Both access site complication rate and overall complication rate were lower for TRA flow diversion compared with TFA in this large series.

IntroductionManaging paediatric hydrocephalus with shunt placement is especially risky in resource-limited settings due to risks of infection and delayed life-threatening shunt obstruction. This study evaluated a new evidence-based treatment algorithm to reduce shunt-dependence in this context.MethodsA prospective cohort design was used. The CURE Protocol employs preoperative and intraoperative data to choose between endoscopic treatment and shunt placement. Data were prospectively collected for 730 children in Uganda (managed by local neurosurgeons highly experienced in the protocol) and, for external validation, 96 children in Nigeria (managed by a local neurosurgeon trained in the protocol).ResultsThe age distribution was similar between Uganda and Nigeria, but there were more cases of postinfectious hydrocephalus in Uganda (64.2% vs 26.0%, pConclusionUse of the CURE Protocol in two centres with different populations and surgeon experience yielded similar 6-month results, with over half of all children remaining shunt-free. Where feasible, this could represent a better public health strategy in low-resource settings than primary shunt placement.

Introduction: Transradial approach (TRA) has gained significant popularity in the neuroendovascular world over the past few years. The purpose of this study is to report early experience in TRA from high volume centers. Methods: We reviewed charts from 4 institutions in the United States to include consecutive patients who underwent diagnostic or interventional neuroendovascular procedure through TRA from July 2018 to July 2019. Collected data included baseline characteristics, procedural variables, whether there was crossover to transfemoral access and complications. Results: A total of 1272 patients were included in the series (age 57.2 ± 15.3, 46.3% females). Out of those, 1054 (82.9%) patients underwent diagnostic cerebral angiograms and 218 (17.1%) underwent interventional procedures. Successfully completed procedures included aneurysm primary coiling (62 patients), stent assisted coiling (44 patients), flow diversion (40 patients), balloon assisted coiling (21 patients), and stroke thrombectomy (24 patients). The large vessels were selected as following: right vertebral artery (VA) in 74.2% of the cases, right internal carotid artery (ICA) in 75.4% of the cases, left VA in 51.4% of the cases, left ICA in 69.1% of the cases. Crossover to femoral access was required in 82 (6.4%) patients (most common cause was inability to reach the target vessel in 13 patients). None of the included patients had major complication related to the access site. Minor complications related to access site were seen in 30 (2.4%) patients. Of those, 11 patients had forearm hematoma, 8 had mild-moderate vasospasm, 6 had forearm pain, and 5 had oozing from the access site. Conclusion: In this early stage of transforming to radial-first approach for neurointerventions, TRA was reasonably safe with relatively low complication rate for both diagnostic and interventional procedures. Wide range of procedures were completed successfully using TRA.

Introduction: There is no definitive evidence currently to guide the choice between general anesthesia (GA) over conscious sedation (CS) for patients undergoing mechanical thrombectomy (MT). As MT outcomes are highly time-sensitive especially in the early time window, we aim to evaluate work-flow metrics and outcome differences between the two approaches in routine clinical practice at a Comprehensive Stroke Center (CSC). Methods: From 2/2015-9/2018, 329 consecutive MT patients were included from a large retrospective CSC database. In late 2017, we implemented a first-choice GA protocol at our CSC from a first choice CS for MT. Baseline characteristics, work-flow metrics and outcomes measures: mRS at discharge, mRS last follow-up (median, IQR 184 days, 37.25-202.5), radiological hemorrhagic conversion (rHT) and symptomatic intracranial hemorrhage (sICH) defined as rHT with post-MT (4-24 hours) NIHSS worsening ≥4, were examined. Multivariate logistic regression model was used to compare workflow and outcomes in GA vs. CS patients. Results: 82 (25.2%) patients received GA and 246 (74.8%) received CS. Baseline characteristics show significantly higher baseline HTN (p .043) and posterior circulation strokes (p .02) in GA patients. Compared to CS, patients undergoing GA had significantly longer procedure times 54±35 vs. 37±22min (OR .98, 95%CI .97-.996) but no difference in onset- or door-to-puncture times. Both had similar first pass success ~57% vs. 53% (p .59), number of attempts 1(1-2) vs. 1(1-2) (p .94) and rate of TICI 2b-3 ~87% vs. 84% (p .85). On multivariate regression, there was no significant difference in outcome measures between GA and CS: rHT (OR 1.1, 95%CI .64-1.9), sICH (OR 1.15, 95%CI .41-3.2), mRS at discharge (OR .75, 95%CI .176-3.22) and mRS at last follow-up (OR 1.05, 95%CI .53-2.08). Conclusion: In routine clinical practice, compared to CS, patients who underwent GA for MT had no difference in clinical outcomes, despite longer procedure times.

Background: Obesity is an established risk factor for acute ischemic stroke (AIS), but its impact on clinical outcomes and mortality after AIS remains controversial. In this study, we evaluate the association of body mass index (BMI) on outcomes after mechanical thrombectomy (MT) for large vessel occlusion acute ischemic stroke (LVOS). Methods: We reviewed our prospective MT database for LVOS between 2015 and 2018. BMI was analyzed as a continuous and categorical variable with underweight BMI 30. Multivariate analysis was used to determine predictors of outcome. Results: 335 patients underwent MT with 7 (2.1%) patients classified as underweight, 107 (31.9%) normal, 141 (42.1%) overweight, and 80 (23.9%) obese. Compared to normal weight (reference), obese patients had higher rates of hypertension and hyperlipidemia, while underweight patients had higher rates of previous stroke and presentation NIHSS. The time from symptom onset to puncture, procedural techniques, and reperfusion success (>TICI 2b) was not significantly different between BMI categories. There was a significant inverse linear correlation between BMI and symptomatic hemorrhagic. In patients with successful reperfusion (>TICI 2b), there was also a significant bell-shaped relationship between BMI and functional independence (mRS < 3) with both low and high BMIs associated with worse outcomes. In patients without post-procedural symptomatic hemorrhage, there was a significant linear correlation between BMI and inpatient mortality. Conclusion: In LVOS patients treated with MT, BMI is inversely related with post-procedural symptomatic hemorrhage. Yet in those whom reperfusion is achieved, both lower and higher than normal BMI were associated with worse functional outcomes. Thus, the obesity paradox does not appear to pertain to mechanical thrombectomy, although larger prospective studies are necessary.

Background: Standard mechanical thrombectomy (MT) techniques utilized include aspiration thrombectomy (ADAPT), stent retriever (SR), and a combination of both (Solumbra). Many studies compare outcomes between ADAPT and SR; however, there has yet to be a large multicenter investigation comparing ADAPT and SR to Solumbra. Methods: All patients from the participating STAR collaboration who underwent MT from 2015-2019 were included. Patients were analyzed by first MT technique utilized (ADAPT, SR, or Solumbra). Univariable and multivariable linear regression was utilized to analyze the MT technique association to number of thrombectomy attempts and procedure time. Univariable and multivariable logistic regression was utilized to determine the association between MT technique and the following outcomes: recanalization, symptomatic hemorrhage, 90-day functional independence, or 90-day mortality. P value less than 0.5 was considered significant. Results: A total of 2515 MT for stroke were identified: 1155 (46%) ADAPT, 735 (29%) SR, 625 (25%) Solumbra. Patients who received Solumbra MT were older (p Conclusion: Compared to standard ADAPT and SR thrombectomy, the Solumbra technique for MT is a longer procedure that results in an increased likelihood of hemorrhage and 90-day mortality.

Introduction: Radiological hemorrhagic transformation (rHT) and symptomatic intracranial hemorrhage (sICH) remain a major complication of mechanical thrombectomy (MT) in acute stroke. Our aim is to identify independent predictors of rHT and sICH. Methods: A retrospective multicenter international study across the US and Europe included 2499 patients, 18 years or older, who underwent EVT for acute stroke from 2015-2019. rHT is defined as any intracranial hemorrhage post MT and subgrouped per ECASS II as petechial (HI), parenchymal hematoma without (PH1) and with mass effect (PH2) and subarachnoid hemorrhage (SAH). sICH was defined as presence of PH2 or SAH. Functional outcomes were described using the 90-day modified Rankin score (mRS) as “good” 0-2 or “poor” 3-6. Multivariable logistic regression model was used to identify predictors of rHT and sICH. Results: 600 (24%) had rHT and 145 (5.8%) had sICH. On multivariable regression model, independent predictors for both rHT and sICH were higher admission NIHSS (OR 1.03, p Conclusion: Compared to posterior circulation, anterior circulation strokes have higher rates of rHT and sICH. Baseline hyperlipidemia is protective for rHT or sICH post MT and this association needs further study. Clinical severity of stroke, poor ASPECTS on admission and higher thrombectomy attempts are associated with higher rates of rHT or sICH. Both rHT and sICH are independently associated with poor functional outcomes.

Background: While CT angiography is the standard tool to identify the site of large vessel occlusion (LVO) in acute ischemic stroke (AIS), CTP may be confirmatory or facilitate identification of the occluded vessel especially in distal LVOs. This study aims to examine the utility of CTP in localizing the site of intracranial large vessel occlusions (LVOs). Method: We reviewed our prospective database of all patients between January 2017 and July 2019 who underwent CTP for suspected AIS. Vascular territories with perfusion abnormalities were recorded. Reference standard for occlusion was defined as confirmed LVO by CTA or digital substraction angiogram (DSA). CTP results were deemed true positive when the identified area with perfusion abnormality was the same as or overlapped with the territory of the occluded vessel on CTA/DSA. Result: We identified 280 stroke alert patients with median NIHSS 11. LVOs were confirmed in 155 patients, of whom 146 showed corresponding perfusion abnormality (sensitivity 94.2%), and 129 with ischemic penumbra. CT perfusion was highly sensitive for occlusions in the MCA (sensitivity 95.7%, 111/116), ICA (100%, 21/21), and PCA (100%, 10/10). CTP only identified 2 of 5 (40%) basilar artery occlusions. CTP sensitivity was 97.2% (69/71), 97.5% (39/40), and 60% (3/5) for occlusions at M1, M2, and M3, respectively. Of the 125 patients who did not have LVO, 54 had falsely positive CT perfusion studies (41 with penumbra) due to stenotic processes, microvascular ischemia, chronic infarcts, or artifacts. In this cohort, 90 patients underwent mechanical thrombectomy, all with confirmed LVOs. 86/90 thrombectomy recipients (95.6%) had perfusion penumbra on initial imaging. Of the remaining 4 thrombectomy recipients who did not demonstrate perfusion mismatch on CTP, 3 had basilar occlusions. Conclusion: CTP is highly sensitive for identifying the site of LVO in the ICA, MCA, and PCA and may be particularly useful in cases of difficult to detect LVOs particularly in M2 and PCA vessels. However, the low specificity of CTP continues to emphasize the importance of correlation with CTA and clinical findings.

BackgroundDiagnostic cerebral angiograms are increasingly being performed by transradial access (TRA) in adults, following data from the coronary literature supporting fewer access-site complications. Despite this ongoing trend in neuroangiography, there has been no discussion of its use in the pediatric population. Pediatric TRA has scarcely been described even for coronary or other applications. This is the first dedicated large study of transradial access for neuroangiography in pediatric patients.MethodsA multi-institutional series of consecutively performed pediatric transradial angiograms and interventions was collected. This included demographic, procedural, outcomes, and safety data. Data was prospectively recorded and retrospectively analyzed.ResultsThirty-seven diagnostic angiograms and 24 interventions were performed in 47 pediatric patients. Mean age, height, and weight was 14.1 years, 158.6 cm, and 57.1 kg, respectively. The radial artery measured 2.09+/-0.54 mm distally, and 2.09+/-0.44 mm proximally. Proximal and distal angiography were performed for both diagnostic and interventional application (17 distal angiograms, two distal interventions). Clinically significant vasospasm occurred in eight patients (13.1%). Re-access was successfully performed 11 times in seven patients. Conversion to femoral access occurred in five cases (8.2%). The only access-related complication was a small asymptomatic wrist hematoma after TR band removal.ConclusionsTransradial access in pediatric patients is safe and feasible. It can be performed successfully in many cases but carries some unique challenges compared with the adult population. Despite the challenge of higher rates of vasospasm and conversion to femoral access, it is worth exploring further, given the potential benefits.

A number of prospective randomized trials have shown that the radial artery is a safer access site than the femoral artery for endovascular procedures.1–4 In the cardiac literature there was a 60% reduction in access site complications as well as significant decreases in all-cause mortality with the transradial approach compared with the transfemoral approach, which has led to the adoption of a radial first strategy.5–7 The neurointerventional literature has demonstrated similar safety benefits as well as improved patient preference.8–14 However, the technical aspects of how to perform neurointervention via the radial approach are still unknown to the majority of neurointerventionalists. This technical video 1 covers the details of how to perform a diagnostic angiogram via the radial approach. Initially, steps such as pre-procedure preparation, room set-up, and patient positioning are discussed. Following this, puncture techniques and sheath placement are outlined, including the snuffbox technique. The steps of a full six-vessel cerebral angiogram are then shown in detail. Finally, closure techniques are demonstrated.Video 1The image in the opening frame and at 2:24 is reused with permission from Brunet et al, Distal transradial access in the anatomical snuffbox for diagnostic cerebral angiography. J Neurointerv Surg 2019;11:710–3. Copyright 2019 BMJ Publishing Group.The other image in the opening frame is reused with permission from Chen et al, Transradial approach for flow diversion treatment of cerebral aneurysms: a multicenter study. J Neurointerv Surg, 2019;11:796-800. Copyright 2019 BMJ Publishing Group.The images at 0:38 and 8:24 are reused with permission from Snelling et al, Transradial cerebral angiography: techniques and outcomes. J Neurointerv Surg 2018;10:874–81. Copyright 2018 BMJ Publishing Group.