Anatomy of Spinal Venous Drainage for the Neurointerventionalist: From Puncture Site to Intervertebral Foramen.

CSF-venous fistula is a relatively novel entity that is increasingly being recognized as a cause for spontaneous intracranial hypotension. Recently, our group published the first series of transvenous embolization of CSF-venous fistulas in this journal. Having now performed the procedure in 60 patients, we have garnered increasing familiarity with the anatomy and how to navigate our way through the venous system to any intervertebral foramen in the cervical, thoracic, and lumbar spine. The first part of this review summarizes the organization of spinal venous drainage as described in classic anatomy and interventional radiology texts, the same works that we studied when attempting our first cases. In the second part, we draw mostly on our own experience to provide a practical roadmap from the puncture site to the foramen. On the basis of these 2 parts, we hope this article will serve to collate the relevant anatomic knowledge and give confidence to colleagues who wish to embark on transvenous spinal procedures.

Postprocedural Thrombosis following Endovascular Treatment of Intracranial Aneurysm with Flow Diverters or Coiling: A Histologic Study.

Endovascular treatment of aneurysms with flow diverters or coiling is sometimes complicated by intraprocedural or postprocedural thrombosis along or within the devices. Thrombus composition and structure associated with such complications may provide insights into mechanisms of thrombus formation and clinical strategies to remove the thrombus. We present a retrospective histopathologic study of 4 patients who underwent mechanical thrombectomy due to acute occlusion of either implanted flow diverter devices or along coils during the treatment of intracranial aneurysm.

Disparities in the Use of Mechanical Thrombectomy Alone Compared with Adjunctive Intravenous Thrombolysis in Acute Ischemic Stroke in the United States.

BACKGROUND AND PURPOSE: For patients with large-vessel occlusion, mechanical thrombectomy (MT) without IV-tPA is a proved strategy. The relative benefit of direct MT versus MT+IV-tPA for patients with indications for IV-tPA is being actively investigated. We used a national inpatient database to assess trends in use and patient profiles after MT+IV-tPA versus mechanical thrombectomy alone. MATERIALS AND METHODS: The National Inpatient Sample was queried between 2013 and 2018 for patients undergoing mechanical thrombectomy for acute ischemic stroke. Patients who received mechanical thrombectomy alone were compared with those who underwent MT+IV-tPA. The Cochran-Armitage test was conducted to assess the linear trend of use of mechanical thrombectomy alone among the entire cohort and between admissions involving non-White and White patients. All estimates were nationalized using discharge weights. RESULTS: A total of 89,645 weighted admissions were identified pertaining to mechanical thrombectomy for acute ischemic stroke from 2013 to 2018. Of these, 59,935 (66.9%) admissions involved mechanical thrombectomy alone. There was an increase in the trend toward the use of mechanical thrombectomy alone (trend: 3.26%; P < .001) per year. Multivariable regression analysis regarding patient profiles indicated that patients who identified as Black (OR = 0.83, P = .001) or Hispanic (OR = 0.79; P < .001) were more likely to undergo mechanical thrombectomy alone compared with those who identified as White. There was no statistically significant difference in the slope between non-White and White populations receiving mechanical thrombectomy alone (trend: +0.93% in favor of non-White; P = .096). CONCLUSIONS: Our results indicated that mechanical thrombectomy alone was used more frequently than MT+IV-tPA among patients with acute ischemic stroke. The disparity between those who identify as White and non-White persisted across the years, though it is closing.

Iatrogenic Foreign Materials Associated with Retrieved Clot Tissue via Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: Hydrophilic polymers and polytetrafluoroethylene liners, commonly used in the construction of endovascular devices, occasionally separate from devices with subsequent embolization. We determined the frequency of such materials in thrombus specimens retrieved by mechanical thrombectomy in patients with stroke. MATERIALS AND METHODS: We retrospectively reviewed H&E-stained thrombus sections for presence and types of foreign materials. We identified 4 types of foreign materials-Type I: material was light green with refraction and had a homogeneous texture; type II: material was light gray and/or dark gray, thin, and loose or attenuated in texture; type III: material was light green with refraction, solitary in texture, irregular in shape, and was often associated with round or oval bubblelike particles and/or diffuse black particles; and type IV: material had homogeneous texture and was light pink or red. In addition, polymer materials from different layers of used mechanical thrombectomy catheters were compared with the foreign materials found in thrombus specimens. RESULTS: A total of 101 thrombi were evaluated. Foreign materials were found in 53 (52.5%) thrombus samples. The most common type was type I (92%), followed by type II (30%). The histopathologic features of the polymer materials from mechanical thrombectomy catheters were similar to the foreign materials found in thrombus specimens. The inner polytetrafluoroethylene liner and coating layer of catheters resembled type I and type II of the foreign materials, respectively. CONCLUSIONS: Foreign polymer materials are present in approximately half of retrieved thrombi, most commonly polytetrafluoroethylene from catheter liners and less from hydrophilic coatings.

Clinical Presentation and Imaging Findings of Patients with Dural Arteriovenous Fistulas with an Angiographic Pseudophlebitic Pattern.

BACKGROUND AND PURPOSE: The pseudophlebitic pattern is an increasingly recognized angiographic manifestation of chronic venous congestion in the setting of a cranial dural arteriovenous fistula. We sought to study the clinical and radiologic manifestations of patients with the pseudophlebitic pattern. MATERIALS AND METHODS: We retrospectively reviewed a cohort of patients with dural arteriovenous fistulas evaluated at our institution from 2008 to 2020. Angiograms were reviewed to classify dural arteriovenous fistulas and document the presence or absence of a pseudophlebitic pattern, defined as the presence of serpiginous and tortuous collateral, bridging, and cortical veins with an associated delay in circulation time of the normal brain. We then studied the association between the pseudophlebitic pattern and clinical presentation and MR imaging findings. RESULTS: Two hundred one patients were included. Patients with a pseudophlebitic pattern had more hemorrhage (22.8% versus 8.4%, P = .005), gait changes and ataxia (6.0% versus 0.0%, P = 0.002), cognitive changes (6.9% versus 1.4%, P = .04), and seizures (8.6% versus 2.1%, P = .03). On MR imaging, the pseudophlebitic pattern was associated with higher rates of cerebral edema (70.9% versus 2.9%, P < .0001), chronic hemosiderin deposition and microhemorrhage (17.3% versus 2.2%, P = .0002), and dilated transmedullary veins (47.1% versus 0.0%, P < .0001). When we considered only patients with malignant fistulas, there was no difference in hemorrhage at presentation between the 2 groups (22.6% versus 22.8%, P = .99). Patients with a pseudophlebitic pattern did have higher rates of nonhemorrhagic neurologic deficits (24.1% versus 9.4%, P = .03). CONCLUSIONS: The pseudophlebitic pattern was associated with high rates of brain parenchymal changes and neurologic symptoms in this cohort of patients with dural arteriovenous fistulas.

Efficacy of Asahi Fubuki as a Guiding Catheter for Mechanical Thrombectomy: An Institutional Case Series.

Treatment outcomes of mechanical thrombectomy for acute stroke secondary to large-vessel occlusion in which the Asahi Fubuki was used as a guide catheter were reviewed. Among 154 patients treated with mechanical thrombectomy, the Fubuki was successfully delivered to the cervical ICA in 151 cases (98.1%) and the lesion was successfully crossed in 150 cases (97.4%). Median times to lesion crossing and revascularization were 9 and 19 minutes, respectively.

A Multicenter Pilot Study on the Clinical Utility of Computational Modeling for Flow-Diverter Treatment Planning.

BACKGROUND AND PURPOSE: Selection of the correct flow-diverter size is critical for cerebral aneurysm treatment success, but it remains challenging due to the interplay of device size, anatomy, and deployment. Current convention does not address these challenges well. The goals of this pilot study were to determine whether computational modeling improves flow-diverter sizing over current convention and to validate simulated deployments. MATERIALS AND METHODS: Seven experienced neurosurgeons and interventional neuroradiologists used computational modeling to prospectively plan 19 clinical interventions. In each patient case, physicians simulated 2-4 flow-diverter sizes that were under consideration based on preprocedural imaging. In addition, physicians identified a preferred device size using the current convention. A questionnaire on the impact of computational modeling on the procedure was completed immediately after treatment. Rotational angiography image data were acquired after treatment and compared with flow-diverter simulations to validate the output of the software platform. RESULTS: According to questionnaire responses, physicians found the simulations useful for treatment planning, and they increased their confidence in device selection in 94.7% of cases. After viewing the simulations results, physicians selected a device size that was different from the original conventionally planned device size in 63.2% of cases. The average absolute difference between clinical and simulated flow-diverter lengths was 2.1 mm. In 57% of cases, average simulated flow-diverter diameters were within the measurement uncertainty of clinical flow-diverter diameters. CONCLUSIONS: Physicians found computational modeling to be an impactful and useful tool for flow-diverter treatment planning. Validation results showed good agreement between simulated and clinical flow-diverter diameters and lengths.

Dilated Vein of the Filum Terminale on MRI: A Marker for Deep Lumbar and Sacral Dural and Epidural Arteriovenous Fistulas.

BACKGROUND AND PURPOSE: Conventional MR imaging can provide important clues regarding the location of a spinal vascular malformation. We hypothesized that a dilated vein of the filum terminale, identified as a curvilinear flow void on T2WI, could be an imaging marker for a lower lumbar (L3-L5) or sacral fistula. MATERIALS AND METHODS: We retrospectively identified all spinal dural and spinal epidural arteriovenous fistulas from 2 large tertiary referral centers from 2005 to 2018. All patients had a lumbar spinal MR imaging and a conventional spinal angiography. Images were reviewed by 2 neuroradiologists who categorized the level of the arterial feeder to the fistula and the presence or absence of a dilated vein of the filum terminale on T2WI and T1 postcontrast images. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the presence of a dilated filum terminale vein for a deep lumbar or sacral fistula. RESULTS: One hundred sixty-two patients were included. An enlarged filum terminale vein was identified in 39 patients. Sensitivity, specificity, positive predictive value, and negative predictive value of the presence of a dilated filum terminale vein for a deep lumbar or sacral fistula were 86%, 98.3%, 94.9%, and 95.1%, respectively. CONCLUSIONS: The presence of a dilated vein of the filum terminale can accurately localize a spinal dural arteriovenous fistula/spinal epidural arteriovenous fistula to the lower lumbar or sacral spine in patients being evaluated for such lesions. This finding can be used to facilitate both noninvasive and conventional spinal angiography.

Review of the Imaging Features of Benign Osteoporotic and Malignant Vertebral Compression Fractures.

Vertebral compression fractures are very common, especially in the elderly. Benign osteoporotic and malignant vertebral compression fractures have extremely different management and prognostic implications. Although there is an overlap in appearances, characteristic imaging features can aid in the distinction between these 2 types of compression fractures. The aim of this review is to characterize the imaging features of benign and malignant vertebral compression fractures seen with CT, PET, SPECT, and MR imaging.

Clinical and Imaging Characteristics of Diffuse Intracranial Dolichoectasia.

BACKGROUND AND PURPOSE: Among patients with vertebrobasilar dolichoectasia is a subset of patients with disease affecting the anterior circulation as well. We hypothesized that multivessel intracranial dolichoectasia may represent a distinct phenotype from single-territory vertebrobasilar dolichoectasia. The purpose of this study was to characterize clinical characteristics and angiographic features of this proposed distinct phenotype termed "diffuse intracranial dolichoectasia" and compare them with those in patients with isolated vertebrobasilar dolichoectasia. MATERIALS AND METHODS: We retrospectively reviewed a consecutive series of patients with diffuse intracranial dolichoectasia and compared their demographics, vascular risk factors, additional aneurysm prevalence, and clinical outcomes with a group of patients with vertebrobasilar dolichoectasia. "Diffuse intracranial dolichoectasia" was defined as aneurysmal dilation of entire vascular segments involving ≥2 intracranial vascular beds. Categoric and continuous variables were compared by using χ2 and Student t tests, respectively. RESULTS: Twenty-five patients had diffuse intracranial dolichoectasia, and 139 had vertebrobasilar dolichoectasia. Patients with diffuse intracranial dolichoectasia were older than those with vertebrobasilar dolichoectasia (70.9 ± 14.2 years versus 60.4 ± 12.5 years, P = .0002) and had a higher prevalence of abdominal aortic aneurysms (62.5% versus 14.3%, P = .01), other visceral aneurysms (25.0% versus 0%, P < .0001), and smoking (68.0% versus 15.9%, P < .0001). Patients with diffuse intracranial dolichoectasia were more likely to have aneurysm growth (46.2% versus 21.5%, P = .09) and rupture (20% versus 3.5%, P = .007) at follow-up. Patients with diffuse intracranial dolichoectasia were less likely to have good neurologic function at follow-up (24.0% versus 57.6%, P = .004) and were more likely to have aneurysm-related death (24.0% versus 7.2%, P = .02). CONCLUSIONS: The natural history of patients with diffuse intracranial dolichoectasia is significantly worse than that in those with isolated vertebrobasilar dolichoectasia. Many patients with diffuse intracranial dolichoectasia had additional saccular and abdominal aortic aneurysms. These findings suggest that diffuse intracranial dolichoectasia may be a distinct vascular phenotype secondary to a systemic arteriopathy affecting multiple vascular beds.

Lack of Association between Statin Use and Angiographic and Clinical Outcomes after Pipeline Embolization for Intracranial Aneurysms.

BACKGROUND AND PURPOSE: Use of statin medications has been demonstrated to improve clinical and angiographic outcomes in patients receiving endovascular stent placement for coronary, peripheral, carotid, and intracranial stenoses. We studied the impact of statin use on long-term angiographic and clinical outcomes after flow-diverter treatment of intracranial aneurysms. MATERIALS AND METHODS: We performed a post hoc analysis from pooled patient-level datasets from 3 Pipeline Embolization Device studies: the International Retrospective Study of the Pipeline Embolization Device, the Pipeline for Uncoilable or Failed Aneurysms Study, and the Aneurysm Study of Pipeline in an Observational Registry. We analyzed data comparing 2 subgroups: 1) patients on statin medication, and 2) patients not on statin medication at the time of the procedure and follow-up. Angiographic and clinical outcomes were compared by using the χ2 test, Fisher exact test, or Wilcoxon rank sum test. RESULTS: We studied 1092 patients with 1221 aneurysms. At baseline, 226 patients were on statin medications and 866 patients were not on statin medications. The mean length of clinical and angiographic follow-up was 22.1 ± 15.1 months and 28.3 ± 23.7 months, respectively. There were no differences observed in angiographic outcomes at any time point between groups. Rates of complete occlusion were 82.8% (24/29) versus 86.4% (70/81) at 1-year (P = .759) and 93.3% (14/15) versus 95.7% (45/47) at 5-year (P = 1.000) follow-up for statin-versus-nonstatin-use groups, respectively. There were no differences in any complication rates between groups, including major morbidity and neurologic mortality (7.5% versus 7.1%, P = .77). CONCLUSIONS: Our study found no association between statin use and angiographic or clinical outcomes among patients treated with the Pipeline Embolization Device.

Intracranial and Extracranial Neurovascular Manifestations of Takayasu Arteritis.

BACKGROUND AND PURPOSE: Takayasu arteritis is a rare, large-vessel vasculitis that presents with symptoms related to end-organ ischemia. While the extracranial neurovascular manifestations of Takayasu arteritis are well-established, little is known regarding the intracranial manifestations. In this study, we characterize the intracranial and cervical neurovascular radiologic findings in patients with Takayasu arteritis. MATERIALS AND METHODS: Patients with Takayasu arteritis who presented to our institution between 2001 and 2016 with intracranial and/or cervical vascular imaging were included in this study. Images were evaluated for the presence of vascular abnormalities, including intracranial or extracranial stenosis, vessel-wall thickening, dissection, subclavian steal, aneurysms, infarcts, and hemorrhages. Descriptive analyses are reported. RESULTS: Seventy-nine patients with Takayasu arteritis met the criteria for inclusion in this study. The most common presenting neurologic symptoms were headache (32.9%) and dizziness (15.2%). Intracranial and extracranial vascular imaging was performed in 84.8% and 89.9% of patients, respectively. Among patients with intracranial vascular imaging, 3 (3.9%) had intracranial aneurysms, 3 (3.9%) had acute large-vessel occlusion, 6 (7.6%) had intracranial vasculitis, and 1 (1.3%) had reversible cerebrovascular constriction syndrome. Among patients with cervical vascular imaging, 42 (53.1%) had some degree of narrowing of the common carotid artery and 18 (22.8%) had narrowing of the ICAs. Seventeen patients (23.6%) had subclavian steal. CONCLUSIONS: Intracranial vascular abnormalities in patients with Takayasu arteritis presenting with neurologic symptoms are not rare, with cerebral vasculitis seen in 7.8% of patients, and stroke secondary to large-vessel occlusion, in 3.9% of patients. Cervical vascular manifestations of Takayasu arteritis were present in most patients in our study.

Diffusion-Weighted Imaging-Detected Ischemic Lesions following Endovascular Treatment of Cerebral Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Endovascular treatment of intracranial aneurysms is associated with the risk of thromboembolic ischemic complications. Many of these events are asymptomatic and identified only on diffusion-weighted imaging. We performed a systematic review and meta-analysis to study the incidence of DWI positive for thromboembolic events following endovascular treatment of intracranial aneurysms. MATERIALS AND METHODS: A comprehensive literature search identified studies published between 2000 and April 2016 that reported postprocedural DWI findings in patients undergoing endovascular treatment of intracranial aneurysms. The primary outcome was the incidence of DWI positive for thromboembolic events. We examined outcomes by treatment type, sex, and aneurysm characteristics. Meta-analyses were performed by using a random-effects model. RESULTS: Twenty-two studies with 2148 patients and 2268 aneurysms were included. The overall incidence of DWI positive for thromboembolic events following endovascular treatment was 49% (95% CI, 42%-56%). Treatment with flow diversion trended toward a higher rate of DWI positive for lesions than coiling alone (67%; 95% CI, 46%-85%; versus 45%; 95% CI, 33%-56%; P = .07). There was no difference between patients treated with coiling alone and those treated with balloon-assisted (44%; 95% CI, 29%-60%; P = .99) or stent-assisted (43%; 95% CI, 24%-63%; P = .89) coiling. Sex, aneurysm rupture status, location, and size were not associated with the rate of DWI positive for lesions. CONCLUSIONS: One in 2 patients may have infarcts on DWI following endovascular treatment of intracranial aneurysms. There is a trend toward a higher incidence of DWI-positive lesions following treatment with flow diversion compared with coiling. Patient demographics and aneurysm characteristics were not associated with DWI-positive thromboembolic events.

Flow Diversion for Ophthalmic Artery Aneurysms.

Endovascular treatments of ophthalmic segment aneurysms are commonly used but visual outcomes remain a concern. We performed a retrospective review of patients with carotid-ophthalmic aneurysms treated with flow diversion from June 2009 to June 2015. The following outcomes were studied through chart review: visual outcomes, complications, postoperative stroke and intraparenchymal hemorrhage, and clinical outcomes. Angiographic outcomes were studied with angiography and MRA at 6 months, 1 year, and 3 years. We evaluated 50 carotid-ophthalmic aneurysms in 48 patients, among whom 44 patients with 46 aneurysms underwent treatment. The mean clinical follow-up was 29 ± 22 months (range, 0-65 months). There were no permanent adverse visual outcomes. There was 1 death because of late intraparenchymal hemorrhage (2.2%). Six-month angiography showed complete occlusion in 24 of 37 patients (64.9%), and 3-year angiography results showed occlusion in 24 of 25 patients (96%). In conclusion, flow diversion is a safe and effective treatment for carotid-ophthalmic aneurysms in carefully selected patients. The risk of adverse visual outcomes is low, and most aneurysms progress to complete occlusion.

Endovascular Coiling of Wide-Neck and Wide-Neck Bifurcation Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: We present the results of a systematic review and meta-analysis examining outcomes of endovascular coiling of wide-neck and wide-neck bifurcation aneurysms with and without stent assistance. The aim of our study was to assess angiographic and clinical outcomes. MATERIALS AND METHODS: We performed a comprehensive literature search for all articles on the endovascular coiling of wide-neck and wide-neck bifurcation aneurysms. Studies meeting our inclusion criteria and abstracted data were selected by 2 independent reviewers. Primary outcomes were >6-month complete or near-complete angiographic occlusion, aneurysm recanalization, and aneurysm retreatment. Secondary outcomes included initial complete or near-complete occlusion, long-term good neurologic outcome, procedure-related morbidity, and procedure-related mortality. Data were analyzed by using random-effects meta-analysis. RESULTS: In total, 38 studies including 2446 patients with 2556 aneurysms were included. For all wide-neck aneurysms, immediate complete or near-complete occlusion rate was 57.4% (95% CI, 48.1%-66.8%). Follow-up near-complete occlusion rate was 74.5% (95% CI, 68.0%-81.0%). Recanalization and retreatment rates were 9.4% (95% CI, 7.1%-11.7%) and 5.8% (95% CI, 4.1%-7.5%), respectively. Long-term good neurologic outcome was 91.4% (95% CI, 88.5%-94.2%). For wide-neck bifurcation aneurysms, initial complete or near-complete occlusion rate was 60.0% (95% CI, 42.7%-77.3%), long-term complete or near-complete occlusion rate was 71.9% (95% CI, 52.6%-91.1%), and the recanalization and retreatment rates were 9.8% (95% CI, 7.1%-12.5%) and 5.2% (95% CI, 1.9%-8.4%), respectively. CONCLUSIONS: Our study of angiographic and clinical outcomes for patients with wide-neck aneurysms demonstrates that endovascular coiling with or without stent-assisted coiling is safe, with low rates of perioperative morbidity and mortality. Initial and long-term angiographic outcomes were generally satisfactory, but not ideal. These data provide some baseline comparisons against which emergent technologies can be assessed.

Aneurysms Associated with Brain Arteriovenous Malformations.

Brain arteriovenous malformations are frequently associated with the presence of intracranial aneurysms at a higher-than-expected incidence based on the frequency of each lesion individually. The identification of intracranial aneurysms in association with AVMs has increased due to improvement in diagnostic techniques, particularly 3D and superselective conventional angiography. Intracranial aneurysms may confer a higher risk of hemorrhage at presentation and of rehemorrhage in patients with AVMs and therefore may be associated with a more unfavorable natural history. The association of AVMs and intracranial aneurysms poses important therapeutic challenges for practicing neurosurgeons, neurologists, and neurointerventional radiologists. In this report, we review the classification and radiology of AVM-associated intracranial aneurysms and discuss their clinical significance and implications for treatment.

Nonaneurysmal Perimesencephalic Hemorrhage Is Associated with Deep Cerebral Venous Drainage Anomalies: A Systematic Literature Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Mechanisms underlying bleeding in nonaneurysmal perimesencephalic SAH remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic SAH and primitive venous drainage of the basal vein of Rosenthal. We performed a meta-analysis to evaluate the relation between primitive basal vein of Rosenthal drainage and nonaneurysmal perimesencephalic SAH. MATERIALS AND METHODS: We performed a comprehensive literature search of all studies examining the prevalence of primitive basal vein of Rosenthal drainage in patients with aneurysmal SAH and nonaneurysmal perimesencephalic SAH. Data collected were primitive basal vein of Rosenthal drainage (direct connection of perimesencephalic veins into the dural sinuses instead of the Galenic system) in at least 1 cerebral hemisphere, normal bilateral basal vein of Rosenthal drainage systems, and the number of overall primitive venous systems in the nonaneurysmal perimesencephalic SAH and aneurysmal SAH groups. Statistical analysis was performed by using a random-effects meta-analysis. RESULTS: Eight studies with 888 patients (334 with nonaneurysmal perimesencephalic SAH and 554 with aneurysmal SAH) and 1657 individual venous systems were included. Patients with nonaneurysmal perimesencephalic SAH were more likely to have a primitive basal vein of Rosenthal drainage in at least 1 hemisphere (47.7% versus 22.1%; OR, 3.31; 95% CI, 2.15-5.08; P < .01) and were less likely to have bilateral normal basal vein of Rosenthal drainage systems than patients with aneurysmal SAH (18.3% versus 37.4%; OR, 0.27; 95% CI, 0.14-0.52; P < .01). When we considered individual venous systems, there were higher rates of primitive venous systems in patients with nonaneurysmal perimesencephalic SAH than in patients with aneurysmal SAH (34.9% versus 15.3%; OR, 3.90; 95% CI, 2.37-6.43; P < .01). CONCLUSIONS: Patients with nonaneurysmal perimesencephalic SAH have a higher prevalence of primitive basal vein of Rosenthal drainage in at least 1 hemisphere than patients with aneurysmal SAH. This finding suggests a venous origin of some nonaneurysmal perimesencephalic SAHs. A primitive basal vein of Rosenthal pattern is an imaging finding that has the potential to facilitate the diagnosis of nonaneurysmal perimesencephalic SAH.

Risk Factors for Ischemic Complications following Pipeline Embolization Device Treatment of Intracranial Aneurysms: Results from the IntrePED Study.

BACKGROUND AND PURPOSE: Risk factors for acute ischemic stroke following flow-diverter treatment of intracranial aneurysms are poorly understood. Using the International Retrospective Study of Pipeline Embolization Device (IntrePED) registry, we studied demographic, aneurysm, and procedural characteristics associated with postoperative acute ischemic stroke following Pipeline Embolization Device (PED) treatment. MATERIALS AND METHODS: We identified patients in the IntrePED registry with post-PED-treatment acute ischemic stroke. The rate of postoperative acute ischemic stroke was determined by demographics, comorbidities, aneurysm characteristics, and procedure characteristics (including anticoagulation use, platelet testing, number of devices used, sheaths, and so forth). Categoric variables were compared with χ(2) testing, and continuous variables were compared with the Student t test. Odds ratios and 95% confidence intervals were obtained by using univariate logistic regression. Multivariate logistic regression analysis was used to determine which factors were independently associated with postoperative stroke. RESULTS: Of 793 patients with 906 aneurysms, 36 (4.5%) patients had acute ischemic stroke. Twenty-six (72.2%) strokes occurred within 30 days of treatment (median, 3.5 days; range, 0-397 days). Ten patients died, and the remaining 26 had major neurologic morbidity. Variables associated with higher odds of acute ischemic stroke on univariate analysis included male sex, hypertension, treatment of MCA aneurysms, treatment of fusiform aneurysms, treatment of giant aneurysms, and use of multiple PEDs. However, on multivariate analysis, the only one of these variables independently associated with stroke was treatment of fusiform aneurysms (OR, 2.74; 95% CI, 1.11-6.75; P = .03). Fusiform aneurysms that were associated with stroke were significantly larger than those not associated with stroke (mean, 24.5 ± 12.5 mm versus 13.6 ± 6.8 mm; P < .001). CONCLUSIONS: Ischemic stroke following PED treatment is an uncommon-but-devastating complication. Fusiform aneurysms were the only variable independently associated with postoperative stroke.

Neurovascular Manifestations of Hereditary Hemorrhagic Telangiectasia: A Consecutive Series of 376 Patients during 15 Years.

BACKGROUND AND PURPOSE: Hereditary hemorrhagic telangiectasia is associated with a wide range of neurovascular abnormalities. The aim of this study was to characterize the spectrum of cerebrovascular lesions, including brain arteriovenous malformations, in patients with hereditary hemorrhagic telangiectasia and to study associations between brain arteriovenous malformations and demographic variables, genetic mutations, and the presence of AVMs in other organs. MATERIALS AND METHODS: Consecutive patients with definite hereditary hemorrhagic telangiectasia who underwent brain MR imaging/MRA, CTA, or DSA at our institution from 2001 to 2015 were included. All studies were re-evaluated by 2 senior neuroradiologists for the presence, characteristics, location, and number of brain arteriovenous malformations, intracranial aneurysms, and nonshunting lesions. Brain arteriovenous malformations were categorized as high-flow pial fistulas, nidus-type brain AVMs, and capillary vascular malformations and were assigned a Spetzler-Martin score. We examined the association between baseline clinical and genetic mutational status and the presence/multiplicity of brain arteriovenous malformations. RESULTS: Three hundred seventy-six patients with definite hereditary hemorrhagic telangiectasia were included. One hundred ten brain arteriovenous malformations were noted in 48 patients (12.8%), with multiple brain arteriovenous malformations in 26 patients. These included 51 nidal brain arteriovenous malformations (46.4%), 58 capillary vascular malformations (52.7%), and 1 pial arteriovenous fistula (0.9%). Five patients (10.4%) with single nidal brain arteriovenous malformation presented with hemorrhage. Of brain arteriovenous malformations, 88.9% (88/99) had a Spetzler-Martin score of ≤2. Patients with brain arteriovenous malformations were more likely to be female (75.0% versus 57.6%, P = .01) and have a family history of hereditary hemorrhagic telangiectasia (95.8% versus 84.8%, P = .04). The prevalence of brain arteriovenous malformation was 19.7% in endoglin (ENG) mutations and 12.5% in activin receptor-like kinase (1ACVRL1) mutations. CONCLUSIONS: Our study of 376 patients with hereditary hemorrhagic telangiectasia demonstrated a high prevalence of brain arteriovenous malformations. Nidal brain arteriovenous malformations and capillary vascular malformations occurred in roughly equal numbers.

Smoking Does Not Affect Occlusion Rates and Morbidity-Mortality after Pipeline Embolization for Intracranial Aneurysms.

BACKGROUND AND PURPOSE: Smoking is a major risk factor for patients with intracranial aneurysms, yet the effects of smoking on outcomes of aneurysm with flow-diverter treatment remain unknown. We studied the impact of smoking on long-term angiographic and clinical outcomes after flow-diverter treatment of intracranial aneurysms. MATERIALS AND METHODS: We retrospectively reviewed data from patients treated with the Pipeline Embolization Device and included in the International Retrospective Study of the Pipeline Embolization Device, the Pipeline for Uncoilable or Failed Aneurysms Study, and the Aneurysm Study of Pipeline in an Observational Registry. Patients were stratified according to smoking status into 3 groups: 1) never smoker, 2) current smoker, and 3) former smoker. We studied angiographic and clinical outcomes. Outcomes were compared by using χ(2) and Student t tests. A multivariate analysis was performed to determine whether smoking was independently associated with poor outcomes. RESULTS: Six hundred sixteen patients with 694 aneurysms were included. Current smokers had a smaller mean aneurysm size compared with the other 2 groups (P = .005) and lower rates of multiple Pipeline Embolization Device use (P = .015). On multivariate analysis, former smokers (OR, 1.08; 95% CI, 0.43-2.71; P = .57) and current smokers (OR, 0.70; 95% CI, 0.27-1.77; P = .38) had similar odds of long-term angiographic incomplete occlusion compared with never smokers. Former smokers (OR, 1.27; 95% CI, 0.64-2.52; P = .25) and current smokers (OR, 0.74; 95% CI, 0.37-1.46; P = .22) had similar odds of major morbidity and neurologic mortality compared with never smokers. CONCLUSIONS: These results suggest that smoking is not associated with angiographic and clinical outcomes among patients treated with the Pipeline Embolization Device. Nonetheless, patients with intracranial aneurysms should continue to be counseled about the risks of tobacco smoking.