A propensity score-matched comparative study of balloon guide catheters versus conventional guide catheters for concurrent mechanical thrombectomy with carotid stenting in tandem strokes: comparison of first pass effect, symptomatic intracranial hemorrhage, and 90-day functional outcomes.

BACKGROUND: Extensive clot burden in tandem strokes accounts for poor mechanical thrombectomy (MT) outcomes. Several studies have shown the benefit of balloon guide catheters (BGCs) in MT and carotid artery stenting. OBJECTIVE: In view of this potential benefit, to investigate the safety and effectiveness of proximal flow arrest using a BGC during concurrent MT and carotid revascularization for tandem stroke treatment in a comparative, propensity score-matched (PSM) study. METHODS: Patients with a tandem stroke identified from our endovascular database were dichotomized into groups treated with BGCs versus conventional guide catheters. One-to-one PSM adjustment for baseline demographics and treatment selection bias using nearest-neighbor matching was performed. Patient demographics, presentation characteristics, and procedural details were recorded. Outcomes assessed were final modified Thrombolysis in Cerebral Infarction (mTICI) grade, periprocedural symptomatic intracranial hemorrhage (sICH) rate, in-hospital mortality, and 90-day modified Rankin Scale (mRS) score. Mann-Whitney U test and multivariate logistic regression were performed to compare procedural parameters and clinical outcomes. RESULTS: Concurrent carotid revascularization (stenting with/without angioplasty) and MT was performed in 125 cases (BGC: 85; no BGC: 40). After PSM (40 patients/group), the BGC group had a significantly shorter procedure duration (77.9 vs 61.5 min; OR=0.996; P=0.006), lower discharge National Institutes of Health Stroke Scale score (8.0 vs 11.0; OR=0.987; P=0.042), and higher odds of 90-day mRS 0-2 score (52.3% vs 27.5%; OR=0.34; P=0.040). On multivariate regression, the BGC group had a significantly higher first pass effect rate (mTICI 2b or 3)(OR=1.115, 95% CI 1.015 to 1.432; P=0.013) and lower periprocedural sICH rate (OR=0.615, 95% CI 0.406 to 0.932; P=0.025). No difference in in-hospital mortality was observed (OR=1.591, 95% CI 0.976 to 2.593; P=0.067). CONCLUSION: BGCs used for concurrent MT-carotid revascularization with flow arrest were safe and resulted in superior clinical and angiographic outcomes in patients with a tandem stroke.

The VEBAS score: a practical scoring system for intracranial dural arteriovenous fistula obliteration.

BACKGROUND: Tools predicting intracranial dural arteriovenous fistulas (dAVFs) treatment outcomes remain scarce. This study aimed to use a multicenter database comprising more than 1000 dAVFs to develop a practical scoring system that predicts treatment outcomes. METHODS: Patients with angiographically confirmed dAVFs who underwent treatment within the Consortium for Dural Arteriovenous Fistula Outcomes Research-participating institutions were retrospectively reviewed. A subset comprising 80% of patients was randomly selected as training dataset, and the remaining 20% was used for validation. Univariable predictors of complete dAVF obliteration were entered into a stepwise multivariable regression model. The components of the proposed score (VEBAS) were weighted based on their ORs. Model performance was assessed using receiver operating curves (ROC) and areas under the ROC. RESULTS: A total of 880 dAVF patients were included. Venous stenosis (presence vs absence), elderly age (<75 vs ≥75 years), Borden classification (I vs II-III), arterial feeders (single vs multiple), and past cranial surgery (presence vs absence) were independent predictors of obliteration and used to derive the VEBAS score. A significant increase in the likelihood of complete obliteration (OR=1.37 (1.27-1.48)) with each additional point in the overall patient score (range 0-12) was demonstrated. Within the validation dataset, the predicted probability of complete dAVF obliteration increased from 0% with a 0-3 score to 72-89% for patients scoring ≥8. CONCLUSION: The VEBAS score is a practical grading system that can guide patient counseling when considering dAVF intervention by predicting the likelihood of treatment success, with higher scores portending a greater likelihood of complete obliteration.

Residual In-Stent Carotid Stenosis and Cigarette Smoking are Independent Predictors of Carotid Restenosis After Carotid Artery Stenting-Results from 738 Carotid Artery Stenting Procedures at a Single Center.

BACKGROUND AND OBJECTIVES: Carotid artery stenting (CAS) has become a viable alternative to carotid endarterectomy for the management of carotid stenosis. Our aim was to determine the rate of radiographic restenosis after CAS and clinical, radiographic, and procedural predictors of in-stent restenosis. METHODS: Our single-center, prospectively maintained database was retrospectively reviewed for CAS procedures performed in symptomatic and asymptomatic patients over 12 years (2010-2022). Baseline demographic data, procedural characteristics, and preprocedural and postprocedural radiographic and clinical details were noted. Baseline characteristics of patients with and without carotid restenosis were compared using the χ2 test for categorical variables and the Student t-test for continuous variables. Univariate and multivariate analyses were performed to determine risk factors associated with restenosis, defined as >70% on digital subtraction angiography. RESULTS: A total of 1017 consecutive CAS procedures were performed in 905 patients during the 12-year period, with 738 in 632 patients included in our study. Our cohort's overall restenosis rate was 17%, with a 14% restenosis rate at 2 years. On multivariate regression analysis, former or current smoking status (odds ratio [OR] = 2.3, 95% CI 1.2-4.1), plaque irregularity (OR 0.55, 95% CI 0.33-0.91), moderate (50.1%-75%) contralateral stenosis (OR 3.2, 95% CI 1.4-7.2), severe (75.1%-99.9%) contralateral stenosis (OR 2.8, 95% CI 1.3-6.0), and residual (>70%) in-stent stenosis after initial stenting (OR 433, 95% CI 80-2346) were significantly associated with carotid restenosis. Area under the curve for the multivariate regression model analysis was 0.78. Patients with <28.6% initial (residual) in-stent stenosis (45/517 cases) had a 9% restenosis rate, whereas those with >28.6% initial in-stent stenosis (77/221 cases) had a 35% restenosis rate. CONCLUSION: In this large, single-center study of carotid artery stenosis treated with CAS, residual in-stent carotid stenosis of approximately 30% and smoking status were independent predictors for restenosis. Maximizing treatment of initial stenosis and smoking cessation education are important steps in preventing future carotid restenosis.

Mechanical thrombectomy in low Alberta stroke program early CT score (ASPECTS) in hyperacute stroke-a systematic review and meta-analysis.

OBJECTIVE: Major randomized controlled trials of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) failed to include a substantial number of patients presenting with low baseline Alberta Stroke Program Early CT Score (ASPECTS:0-5). Patients experiencing hyperacute strokes (last known well ≤ 6 h) can potentially benefit most from MT. We conducted a systematic review and meta-analysis to report presentation severity and radiographic and clinical outcomes for hyperacute stroke patients presenting with low-ASPECTS. METHODS: Our comprehensive literature search of PubMed, Embase, and Cochrane databases up to August 31, 2022 included articles reporting patients presenting hyperacutely who underwent MT for anterior circulation large vessel occlusion AIS with an ASPECTS ≤ 5 on baseline imaging. Pooled averages were calculated for age and presenting National Institutes of Health Stroke Scale (NIHSS). Fixed- and random-effects meta-analyses for weighted estimation of overall rates were performed. Forest plots were generated for proportions and estimated overall outcome rates. RESULTS: 18 studies (1958 patients) were included (mean age = 64.1 years; presenting NIHSS = 18.4). Final modified thrombolysis in cerebral infarction 2b-3 grade was achieved in 76.4%, with symptomatic intracranial hemorrhage in 12.1%. Good (modified Rankin Scale [mRS] 0-2) and ambulatory (mRS 0-3) 3-month outcomes were achieved by 27.4 and 46.7%, respectively; 90-day mortality was 26.4%. CONCLUSION: MT in low-ASPECTS hyperacute stroke patients may result in ambulatory clinical outcomes with acceptable hemorrhage risk. Recanalization rates achieved were similar to those in patients presenting with ASPECTS ≥ 6; this did not fully translate to better clinical outcomes. ADVANCES IN KNOWLEDGE: MT should be considered for hyperacute strokes with low presenting ASPECTS.

Expansion and Subsequent Rupture of Carotid Pseudoaneurysm After Tandem Carotid and Middle Cerebral Artery Occlusion Treated With Mechanical Thrombectomy and Carotid Stenting.

BACKGROUND AND IMPORTANCE: Extracranial carotid artery pseudoaneurysm is a rare entity with potential etiologies including infection, blunt trauma, postsurgical atherosclerotic disease, and invasive neoplasia. Although the natural history of carotid pseudoaneurysm is difficult to determine because of its rarity, complications such as stroke, rupture, and local mass effect may occur at staggering rates. CLINICAL PRESENTATION: In this case, a middle-aged man presented with a tandem carotid, middle cerebral artery occlusion that was treated with a carotid stent and mechanical thrombectomy. He returned 3 weeks later with a ruptured carotid pseudoaneurysm that was then treated with a covered stent. He made a full recovery and was neurologically intact on follow-up. CONCLUSION: This case illustrates a rare potential complication of carotid occlusion and stenting with possible catastrophic consequences. The goal of this report was to educate other clinicians in remaining vigilant in awareness of this complication and provide a framework for potential treatment if and when it occurs.

The first decade of flow diversion for intracranial aneurysms with the Pipeline embolization device.

OBJECTIVE: Flow diverter devices have revolutionized the treatment of intracranial aneurysms (IAs) since their approval in 2011 and have continued to evolve. The devices have been widely adopted across institutions and centers over the past decade; however, long-term follow-up after treatment with the Pipeline embolization device (PED) is not well described in the literature. The authors' institution was among the first to begin using PEDs, allowing them to report their series of patients treated with flow diverters ≥ 10 years ago. In this study, the authors aimed to evaluate the long-term angiographic and clinical outcomes of these patients and review lessons learned along the way. METHODS: The authors performed a retrospective review of their institution's IA database from January 2007 to July 2012. All patients with IAs treated with a PED prior to July 2012 were included. Clinical and angiographic characteristics were extracted. Available angiographic follow-up at 1, 3, 5, and 10 years was reported. RESULTS: A total of 83 patients with 92 aneurysms treated with a PED ≥ 10 years ago were identified and included in the study. The mean aneurysm dome diameter was 9.2 (SD 5.7) mm, the mean aneurysm height was 10.4 (SD 6.8) mm, and the mean neck width was 4.1 (SD 2.4) mm. Only 1 (1.1%) aneurysm was ruptured at presentation. Eight (8.7%) aneurysms were recurrences of previous treatment modalities. The morphology was saccular in 77 (83.7%) aneurysms, fusiform in 14 (15.2%), and blister-like in 1 (1.1%). Among saccular aneurysms, 60 (77.9%) were wide-necked. Seventy-five (81.5%) aneurysms were in the internal carotid artery, 12 (13.0%) were vertebrobasilar, 3 (3.3%) were in the middle cerebral artery, and 2 (2.2%) were in the posterior cerebral artery. Angiographic follow-up at 1, 3, 5, and 10 years was available for 75, 59, 50, and 15 patients, respectively. The complete occlusion rates at 1, 3, 5, and 10 years were 94.7%, 96.6%, 96.0%, and 100%, respectively. The retreatment rates at 1, 3, 5, and 10 years were 8.0%, 6.8%, 8.0%, and 6.7%, respectively. CONCLUSIONS: The authors provide their single-institution series of IA patients treated with a PED ≥ 10 years ago, with the first report of 10-year follow-up for the available patients.

Hyperacute stenting and angioplasty for acute extracranial non-tandem internal carotid artery strokes within the first 48†h: A 20-year experience and a systematic review and meta-analysis.

BACKGROUND: Acute strokes involving complete, isolated occlusion of the extracranial cervical internal carotid artery (EC-ICA) with no intracranial clot burden account for a minority of stroke cases that are managed variably. Here we present our two-decade experience and a systematic review of endovascular management of acute isolated EC-ICA strokes in the hyperacute phase (<48 h) and attempt to evaluate clinical effectiveness and safety. METHODS: Our prospectively maintained database was retrospectively searched for patients who presented between January 1, 2003 and December 31, 2022 with acute cervical ICA stroke confirmed on angiography. Only patients who had an isolated 100% occlusion of the cervical ICA segment and attempted acute stenting with/without angioplasty within the first 48 h of time since last known well were included. Demographics, procedural details, and outcomes were recorded. For the systematic review, a search of PubMed and Embase databases was conducted. RESULTS: Forty-six patients with acute, isolated EC-ICA occlusive stroke were included. Median presenting National Institutes of Health Stroke Scale (NIHSS) score was 8 (interquartile range 3-10) with a perfusion deficit in 78.3% of the 40 cases assessed with computed tomography perfusion imaging. Median time from symptom onset to intra-arterial puncture was 14.4 h. Immediate recanalization was achieved in 82.6% cases. Two cases (4.3%) of symptomatic intracranial hemorrhage (sICH) occurred postprocedure. Outcome measures were stable or improved discharge NIHSS score in 86.9% of cases, functional independence at 90 days (modified Rankin scale score ≤2) in 78.3%, and mortality in 6.5%. The systematic review included 167 patients from four articles. The estimated rate of immediate recanalization was 92.7% (95% confidence interval (CI), 88.77-96.77%), favorable outcome was 62.01% (95% CI, 55.04-69.87%), and sICH was 6.2% (95% CI, 3.41-11.32%). CONCLUSION: Stenting and angioplasty for acute cervical ICA occlusive strokes during the hyperacute phase can be performed successfully with favorable clinical outcomes and an acceptable recanalization rate.

Mechanical thrombectomy versus medical management for acute basilar artery occlusions: A meta-analysis of randomized trials.

BACKGROUND: Basilar artery occlusion (BAO) stroke is a catastrophic clinical event that results in significant morbidity and mortality. Whether MT is superior in improving outcomes remains largely inconclusive. We performed a meta-analysis of randomized controlled trials (RCTs) to better understand the efficacy and safety of MT in treating BAO compared to medical management (MM). METHODS: PubMed and EMBASE were searched to identify RCTs that directly compared the safety and efficacy of MT versus MM for patients with BAO. The primary outcome was modified Rankin scale (mRS) 0-3 at 3 months, and secondary outcome variables included National Institutes of Health Stroke Scale (NIHSS) at 24 hours, mRS 0-2 at 3 months, symptomatic intracranial hemorrhage (sICH), and 90-day mortality. RESULTS: Four RCTs with 988 patients (432 in the MM arm and 556 in the MT arm), were included. Patients receiving MT had significantly higher rate of mRS 0-2 (OR = 1.994, 95% CI: 1.319-3.012) and mRS 0-3 (OR = 2.259, 95% CI: 1.166-4.374) at 3 months in comparison to patients receiving MM. Mortality was also significantly reduced in the MT group (OR = 0.640, 95% CI: 0.493-0.831). However, increased odds of sICH were found in the MT group compared to the MM group (OR = 8.193, 95% CI: 2.451-27.389). No difference was observed in terms of NIHSS at 24 hours between the two arms. CONCLUSIONS: Despite the higher risk of sICH, MT was associated with superior functional outcomes and reduced mortality compared to MM in BAO patients. A revision of current guidelines for treatment of acute ischemic stroke from basilar artery occlusion should be considered.

Natural history, angiographic presentation and outcomes of anterior cranial fossa dural arteriovenous fistulas.

BACKGROUND: Anterior cranial fossa dural arteriovenous fistulas (ACF-dAVFs) are aggressive vascular lesions. The pattern of venous drainage is the most important determinant of symptoms. Due to the absence of a venous sinus in the anterior cranial fossa, most ACF-dAVFs have some degree of drainage through small cortical veins. We describe the natural history, angiographic presentation and outcomes of the largest cohort of ACF-dAVFs. METHODS: The CONDOR consortium includes data from 12 international centers. Patients included in the study were diagnosed with an arteriovenous fistula between 1990-2017. ACF-dAVFs were selected from a cohort of 1077 arteriovenous fistulas. The presentation, angioarchitecture and treatment outcomes of ACF-dAVF were extracted and analyzed. RESULTS: 60 ACF-dAVFs were included in the analysis. Most ACF-dAVFs were symptomatic (38/60, 63%). The most common symptomatic presentation was intracranial hemorrhage (22/38, 57%). Most ACF-dAVFs drained through cortical veins (85%, 51/60), which in most instances drained into the superior sagittal sinus (63%, 32/51). The presence of cortical venous drainage predicted symptomatic presentation (OR 9.4, CI 1.98 to 69.1, p=0.01). Microsurgery was the most effective modality of treatment. 56% (19/34) of symptomatic patients who were treated had complete resolution of symptoms. Improvement of symptoms was not observed in untreated symptomatic ACF-dAVFs. CONCLUSION: Most ACF-dAVFs have a symptomatic presentation. Drainage through cortical veins is a key angiographic feature of ACF-dAVFs that accounts for their malignant course. Microsurgery is the most effective treatment. Due to the high risk of bleeding, closure of ACF-dAVFs is indicated regardless of presentation.

Somatic Variants in SVIL in Cerebral Aneurysms.

Background and Objectives: While somatic mutations have been well-studied in cancer, their roles in other complex traits are much less understood. Our goal is to identify somatic variants that may contribute to the formation of saccular cerebral aneurysms. Methods: We performed whole-exome sequencing on aneurysm tissues and paired peripheral blood. RNA sequencing and the CRISPR/Cas9 system were then used to perform functional validation of our results. Results: Somatic variants involved in supervillin (SVIL) or its regulation were found in 17% of aneurysm tissues. In the presence of a mutation in the SVIL gene, the expression level of SVIL was downregulated in the aneurysm tissue compared with normal control vessels. Downstream signaling pathways that were induced by knockdown of SVIL via the CRISPR/Cas9 system in vascular smooth muscle cells (vSMCs) were determined by evaluating changes in gene expression and protein kinase phosphorylation. We found that SVIL regulated the phenotypic modulation of vSMCs to the synthetic phenotype via Krüppel-like factor 4 and platelet-derived growth factor and affected cell migration of vSMCs via the RhoA/ROCK pathway. Discussion: We propose that somatic variants form a novel mechanism for the development of cerebral aneurysms. Specifically, somatic variants in SVIL result in the phenotypic modulation of vSMCs, which increases the susceptibility to aneurysm formation. This finding suggests a new avenue for the therapeutic intervention and prevention of cerebral aneurysms.

"Recycling" A Failed Superficial Temporal Artery Indirect Bypass into a Double Barrel Direct Bypass in Moyamoya Disease.

OBJECTIVES: Moyamoya disease is an idiopathic cerebrovascular disorder in which patients experience recurrent transient ischemic attacks, ischemic or hemorrhagic strokes, headaches, and seizures from progressive stenosis of the vessels of the anterior circulation. The mainstay of treatment in symptomatic patients is surgical revascularization. Here, we present the case of a moyamoya patient in which a failed encephaloduroarteriosynangiosis, after new strokes, is recycled and converted into a combined "double barrel" direct superficial temporal artery to middle cerebral artery bypass with included video. CASE REPORT/RESULTS: We describe a 37-year-old woman with a history of hypertension, obstructive sleep apnea, celiac disease, and moyamoya disease complicated by multiple ischemic strokes who presented with progressive dysarthria, dysphagia, and new left-sided ischemic infarcts. The patient had previously undergone right-sided direct bypass and left-sided encephaloduroarteriosynangiosis in the setting of multiple ischemic strokes. After more strokes, the patient underwent a left-sided frontotemporoparietal craniotomy for conversion of the failed indirect bypass into a "double barrel" direct bypass. CONCLUSIONS: The literature is divided over which revascularization procedure should be preferred. Irrespectively, most failed bypass grafts are repaired via direct bypasses, to good effect. We highlight a case in which a failed indirect bypass is directly incorporated into a combined direct bypass with resulting restoration of blood flow. In the case of a failed indirect bypass in an adult patient with moyamoya disease, this method provides the operator with an additional option for restoration of perfusion, especially in patients without other viable vessels available for anastomosis.

Association of Reproductive Life Span and Age at Menopause With the Risk of Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND AND OBJECTIVES: Subarachnoid hemorrhage from cerebral aneurysm remains a devastating disease with high mortality and morbidity. Cerebral aneurysm and its rupture are more prevalent in postmenopausal women and have been postulated to be hormonally influenced. The goal of this study was to investigate the associations of female-specific factors, including reproductive life span, age at menarche, and age at menopause, with the incidence of aneurysmal subarachnoid hemorrhage (aSAH) in women. METHODS: Participants in the Nurses' Health Study were followed up from 1980 or the time of reaching menopause until 2018. Only women with natural menopause or surgical menopause due to bilateral oophorectomy were included. Reproductive life span was defined by subtracting the age at menarche from the age at menopause. Multivariable-stratified proportional hazards models were used to study reproductive life span, age at menarche, and age at menopause with the incidence of aSAH. Multivariable models were adjusted for age, race, smoking, hysterectomy, hypertension, hyperlipidemia, body mass index, hormone therapy use, oral contraceptive use, and parity. RESULTS: A total of 97,398 postmenopausal women with reproductive life span data were included; 138 participants developed aSAH, which was confirmed on medical record review by a physician. A shorter reproductive life span (≤35 years) was associated with a 2-fold higher incidence of aSAH after multivariable adjustment (hazard ratio [HR] 2.0 [95% CI 1.4-2.8]). Early age at menopause (age <45 years) was similarly associated with a higher risk of aSAH (HR 2.1 [95% CI 1.4-3.1]), but age at menarche was not. Use of oral contraceptives and postmenopausal hormone therapy was not associated with the incidence of aSAH. DISCUSSION: An earlier age at menopause and a shorter reproductive life span duration (≤35 years) were associated with a higher risk of incident aSAH in women. No associations were noted for age at menarche, parity, oral contraceptive use, or postmenopausal therapy use.

Asymptomatic Moyamoya Disease in a North American Adult Cohort.

OBJECTIVE: The natural history of asymptomatic adult moyamoya disease (MMD) is unclear, and the benefit of treatment remains controversial. This study aimed to investigate the natural history of asymptomatic MMD in a North American cohort and to evaluate risk factors associated with and the effects of treatment on disease progression. METHODS: Medical records from 3 institutions of consecutive adult patients with MMD diagnosed between 1984 and 2018 were retrospectively reviewed. Patients with unilateral or bilateral asymptomatic MMD were evaluated for subsequent development of infarction or hemorrhage. Multivariate Cox proportional hazards regression assessed risk factors associated with infarction or hemorrhage, adjusting for age, sex, race, initial Suzuki grade, hypertension, hyperlipidemia, diabetes, obesity, presence of aneurysms, smoking status, aspirin, and statin use at diagnosis. RESULTS: We identified 106 hemispheres with asymptomatic MMD in 97 patients with mean 5.1 years (interquartile range, 1.0-7.9 years) of follow-up. Of 106 hemispheres, 59 were treated medically, and 47 were treated with revascularization with direct or indirect bypasses. The medical and surgical cohorts had a 1.9% and 1.3% annual rate of radiographic infarction or hemorrhage per hemisphere, respectively. Cox regression for radiographic events, including early postoperative events, showed no significant difference between the treatment groups (adjusted hazard ratio 0.34 [95% confidence interval 0.05-2.5]). CONCLUSIONS: We found an overall 1.7% annual rate of radiographic infarction or hemorrhage in asymptomatic MMD hemispheres. Although we did not find a benefit to surgical treatment within the study period, asymptomatic patients with expected long-term survival may benefit from surgery given the sustained long-term benefits after surgery despite an initial postoperative risk.

Safety Profile and Factors Associated With Good Outcome for Endovascularly Treated Infectious Intracranial Aneurysms.

BACKGROUND: Infectious intracranial aneurysms (IIAs), or mycotic aneurysms, are infectious inflammatory lesions that can cause devastating neurological damage or death. Recent systemic reviews have suggested endovascular treatment to be efficacious for IIA management. OBJECTIVE: To compare the safety profile of different endovascular methods for treating ruptured and unruptured IIAs and factors associated with good clinical and radiographic outcomes. METHODS: We conducted a retrospective single study of endovascularly treated ruptured and unruptured IIAs between 2003 and 2019. Univariate and multivariate analyses were used to study patient presentation, endovascular treatments used, and clinical and radiographic outcomes. RESULTS: Thirty-eight patients with ruptured (n = 20) and unruptured (n = 18) IIAs treated with endovascular methods were included. One patient required retreatment after aneurysm recanalization, and 2 patients demonstrated new infarcts after embolization. There was no postprocedural radiographic hemorrhage or infarct and no difference in clinical and radiographic outcomes comparing treatment modality. Hypertension was associated with ruptured IIA status and worse clinical outcome at 6 mo (odds ratio: 0.03 [95% confidence interval: 0.002-0.52]). CONCLUSION: In this study, the largest single-center series to date, we showed that endovascular intervention is a safe and effective strategy for both ruptured and unruptured IIAs. Hypertension was associated with ruptured status and worse clinical outcome. Procedures are generally well-tolerated and safe, with good outcomes for patients.

Geometric Features Associated with Middle Cerebral Artery Bifurcation Aneurysm Formation: A Matched Case-Control Study.

OBJECTIVES: The pathogenesis of intracranial aneurysms is multifactorial and includes genetic, environmental, and anatomic influences. We aimed to identify image-based morphological parameters that were associated with middle cerebral artery (MCA) bifurcation aneurysms. MATERIALS AND METHODS: We evaluated three-dimensional morphological parameters obtained from CT angiography (CTA) or digital subtraction angiography (DSA) from 317 patients with unilateral MCA bifurcation aneurysms diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016. We chose the contralateral unaffected MCA bifurcation as the control group, in order to control for genetic and environmental risk factors. Diameters and angles of surrounding parent and daughter vessels of 634 MCAs were examined. RESULTS: Univariable and multivariable statistical analyses were performed to determine statistical significance. Sensitivity analyses with smaller (≤ 3 mm) aneurysms only and with angles excluded, were also performed. In a multivariable conditional logistic regression model we showed that smaller diameter size ratio (OR 0.0004, 95% CI 0.0001-0.15), larger daughter-daughter angles (OR 1.08, 95% CI 1.06-1.11) and larger parent-daughter angle ratios (OR 4.24, 95% CI 1.77-10.16) were significantly associated with MCA aneurysm presence after correcting for other variables. In order to account for possible changes to the vasculature by the aneurysm, a subgroup analysis of small aneurysms (≤ 3 mm) was performed and showed that the results were similar. CONCLUSIONS: Easily measurable morphological parameters of the surrounding vasculature of the MCA may provide objective metrics to assess MCA aneurysm formation risk in high-risk patients.

Dural arteriovenous fistulas without cortical venous drainage: presentation, treatment, and outcomes.

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.

Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR): rationale, design, and initial characterization of patient cohort.

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.

Recurrence after cure in cranial dural arteriovenous fistulas: a collaborative effort by the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR).

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.

Assessing the rate, natural history, and treatment trends of intracranial aneurysms in patients with intracranial dural arteriovenous fistulas: a Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) investigation.

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.