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BackgroundWEB treatment is an endovascular approach for wide-neck bifurcation aneurysms that has demonstrated high safety and good efficacy in mid-term follow-up. While evaluating safety in the long term is important to determine if delayed adverse events occur affecting late morbidity and mortality, the most important point to evaluate is the long-term stability of aneurysm occlusion. The current analysis reports the 3-year clinical and anatomical results of WEB treatment in the combined population of two European trials (WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm Therapy) and WEBCAST-2).MethodsAneurysm occlusion was evaluated using a 3-grade scale: complete occlusion, neck remnant, and aneurysm remnant.ResultsThe safety population comprised 79 patients. The efficacy population comprised 61 aneurysms. Aneurysm locations were middle cerebral artery in 32/61 aneurysms (52.5%), anterior communicating artery in 13/61 (21.3%), basilar artery in 9/61 (14.8%), and internal carotid artery terminus in 7/61 (11.5%). No adverse events related to the device or procedure occurred between 2 and 3 years. At 3 years, complete occlusion was observed in 31/61 (50.8%) aneurysms, neck remnant in 20/61 (32.8%), and aneurysm remnant in 10/61 (16.4%). Between 1 year and 3 years, aneurysm occlusion was improved or stable in 53/61 (86.9%) aneurysms and worsened in 8/61 (13.1%). Worsening was mostly from complete occlusion to neck remnant in 6/61 (9.8%) aneurysms. The retreatment rate at 3 years was 11.4%.ConclusionsThis analysis confirms the high safety profile of WEB. Moreover, evidence demonstrates the great stability of aneurysm occlusion with adequate occlusion (complete occlusion or neck remnant) in 83.6% of aneurysms.Clinical trial registrationURL:http://www.clinicaltrials.gov. WEBCAST and WEBCAST-2: Unique identifier:NCT01778322.

Although the cost of clinical trials is ever-increasing, in-silico trials, which rely on virtual populations and interventions simulated using patient-specificc models, may offer a solution to contain these costs. However, in-silico trial endpoints need to be compared to those available from conventional clinical trials to ensure that the predictions of safety or effcacy from the in-silico approach are valid. Here, we present the flow diverter performance assessment (FDPASS) in-silico trial, which modelled the treatment of intracranial aneurysms in 82 virtual patients with a flow-diverting stent, using computational fluid dynamics (CFD) to quantify post-treatment flow reduction in the aneurysm sac. The predicted FD-PASS flow-diversion success rate replicated the values previously reported in three reference clinical trials. The in-silico approach allowed broader investigation of factors associated with insuficient flow reduction and increased stroke risk after flow diversion than would be feasible in a conventional trial. These ndings demonstrate for the rst time that in-silico trials of medical devices can (i) replicate ndings of conventional clinical trials and (ii) incorporate virtual experiments that are impossible in conventional trials.

Introduction: The mechanisms linking obesity to increased mortality in patients with coronavirus-disease 2019 (COVID-19) are unclear. Hypothesis: We hypothesised that obesity would be associated with adverse right ventricular (RV) remodelling and function which might be further exacerbated by COVID-19 associated increases in RV afterload/demand. Methods: We used echocardiography and computed tomography to establish links between RV dimensions and function and bodyweight in patients with severe COVID-19. In obese and non-obese participants without COVID-19, we used cardiovascular magnetic resonance to define the effects of obesity upon RV volumes, energetics, systolic function and stress reserve. Results: In patients with severe COVID-19, increasing bodyweight was associated with disproportionate RV dilatation (n=26, echocardiography, R=0.42, P=0.03, CT n=34, R=0.23, P=0.004) and impairment of RV systolic function (fractional area change (FAC) R=-0.45, P=0.04); obesity (BMI >30kg/m2) was associated with a 32% reduction in RV FAC (P=0.03). Similar associations were seen in a validation cohort (n=91, all P2 ) was associated with RV remodelling, impaired cardiac energetics (PCr/ATP ratio 23% lower, P2 , n=27) had impaired RV diastolic filling rate at rest (P Conclusions: Increasing body weight is associated with both significant alterations in RV volumes, systolic function and stress responses which are mitigated with weight loss and also with disproportionate RV dilatation and dysfunction in severe COVID-19. RV dysfunction is a modifiable mechanism which might link obesity to adverse outcomes in patients with COVID-19 and other disorders stressing the right heart.

Purpose: To establish the feasibility of using vessel-encoded pseudocontinuous arterial spin labeling (VEPCASL) for non-invasive vascular territory imaging (VTI) and artery-specific dynamic angiography of a large number of arterial branches above the circle of Willis within a clinically feasible scan time. Methods: 3D time-of-flight angiography was used to select a labeling plane and establish seven pairs of encoding cycles. These were used for VEPCASL VTI and dynamic 2D angiography (8 min and 3 min acquisition times, respectively) in healthy volunteers, allowing the separation of signals arising from 13 arterial branches (including extracranial arteries) in post-processing. To demonstrate the clinical potential of this approach, VEPCASL angiography was also applied in five patients with brain arteriovenous malformation (AVM). Results: In healthy volunteers, the artery-specific filling of the vascular tree and resulting perfusion territories were well depicted. Signal-to-noise ratios were approximately five times higher than those achievable with single-artery selective methods. Blood supply to the AVMs was well visualized in all cases, showing the main feeding arteries and venous drainage. Conclusions: VEPCASL is a highly efficient method for both VTI and dynamic angiography of a large number of arterial branches, providing a comprehensive picture of vascular flow patterns and the effect on downstream tissue perfusion within an acceptable scan time. Automation of labeling plane and vessel-encoding selection would improve robustness and efficiency, and further refinement could allow quantitative blood flow measurements to be obtained. This technique shows promise for visualizing the blood supply to lesions and collateral flow patterns.

Introduction/Purpose Flow Disruption with WEB is an innovative endovascular approach for wide-neck bifurcation aneurysms that has been evaluated in 3 European Good Clinical Practice Studies: WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm), French Observatory, and WEBCAST-2. This treatment is associated with a high safety and efficacy at one year.1 Long-term anatomical results have been very few evaluated. The present work is presenting the 2-years safety and efficacy results in the 3 GCP studies. Materials and methods Out of the 168 patients with 169 aneurysms initially included in the 3 GCP studies, 138 patients were clinically evaluated at 2 years and 120 patients with 121 aneurysms were evaluated by vascular imaging. Results There was no bleeding/rebleeding or thromboembolic complication between 1 year and 2 years. Morbidity and mortality at 2 years were 1.4% (2/138) and 5.1% (7/138), respectively. Two deaths (1.4%) were related to the procedure (retroperitoneal hematoma and brainstem compression). The other deaths were unrelated to the disease or the procedure (cancer: 3 patients; pneumonia: 1 patient; cirrhosis: 1 patient). Anatomical results at 2 years were complete occlusion in 62/121 aneurysms (51.2%), neck remnant in 36/121 aneurysms (29.8%), and aneurysm remnant in 23/121 aneurysms (19.0%). Anatomical results were similar in aneurysms treated with WEB DL and WEB SL/SLS. Between 1 and 2 years, aneurysm occlusion was stable or improved in 103/119 aneurysms (86.6%). Aneurysm retreatment was performed in 14 aneurysms (9.3%), 11 between the procedure and 1 year and in 3 between 1 and 2 years. Conclusion The great safety and efficacy of WEB aneurysm treatment is confirmed at 2 years follow-up. No adverse events are observed between 1 year and 2 years. Adequate occlusion is observed in a similar percentage of aneurysms at 1 year (79.1%) and 2 years (81.0%). 1 Pierot L, Soize S, Molyneux A, Byrne J, Spelle. Evaluation of the Safety and Efficacy of Aneurysm Treatment with WEBTM device in the cumulated population of 3 prospective, multicenter series (WEBCAST, French Observatory, WEBCAST-2). J NeuroIntervent Surg. 2018;10:553–559. Disclosures L. Pierot: 2; C; Balt, Medtronic, Microvention, Phenox, Vesalio. X. Barreau: None. I. Szikora: None. D. Herbreteau: None. J. Byrne: None. L. Spelle: None.

BACKGROUND AND PURPOSE: Although the role of wall shear stress (WSS) in the initiation, growth, and rupture of intracranial aneurysms has been well studied, its influence on aneurysm recurrence after endovascular treatment requires further investigation. We aimed to compare WSS at necks of recurrent and nonrecurrent aneurysms. METHODS: Nine recurrent coil-embolized aneurysms were identified and matched with nine nonrecurrent aneurysms. Patient-specific vessel geometries reconstructed from follow-up 3-D time-of-flight magnetic resonance angiography were analyzed using computational fluid dynamics (CFD) simulations. Absolute WSS and the percentage of abnormally low and high WSS at the aneurysm neck compared to the near artery were measured. RESULTS: The median percentage of abnormal WSS at the aneurysm neck was 49.3% for recurrent and 34.7% for nonrecurrent aneurysms (P = .011). The area under the receiver-operating-characteristic curve for distinguishing these aneurysms according to the percentage of abnormal WSS was .86 (95% CI .62 to .98). The optimal cut-off value of 45.1% resulted in a sensitivity and a specificity of 88.89% (95% CI 51.8% to 99.7%). CONCLUSION: Our findings indicate that necks of recurrent aneurysms are exposed to abnormal WSS to a larger extent. Abnormal WSS may serve as a metric to distinguish them from nonrecurrent aneurysms with CFD simulations a priori.

BACKGROUND Flow disruption with WEB is an innovative endovascular approach for wide-neck bifurcation aneurysms. Initial series have shown a low complication rate with good efficacy. OBJECTIVE To report clinical and anatomical results of the WEB treatment in the cumulated population of WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm) and French Observatory series. METHODS WEBCAST and French Observatory are single-arm, prospective, multicenter, Good Clinical Practice studies dedicated to the evaluation of WEB treatment. Ruptured and unruptured bifurcation aneurysms located in the basilar artery, middle cerebral artery, anterior communicating artery, and internal carotid artery terminus were included in both studies. Clinical data were independently evaluated. Postoperative, 6-month (in WEBCAST), and 1-year aneurysm occlusion was independently evaluated with a 3-grade scale: complete occlusion, neck remnant, and aneurysm remnant. RESULTS The cumulated population was 113 patients (74 female, 65.5%) 33 to 74 years of age with 114 aneurysms with a mean neck size of 5.6 mm. There was no mortality at 1 month, and morbidity was 2.7%. A statistically significant difference in the rate of occurrence of thromboembolic events was observed between the use of any antiplatelet agent and the use of no antiplatelet agent (P < .001). At 1 year, complete aneurysm occlusion was observed in 56.0%, neck remnant in 26.0%, and aneurysm remnant in 18.0%. Worsening of aneurysm occlusion between the procedure and 12 months was observed in 2.0% and between 6 months and 1 year in 7.1%. CONCLUSION The analysis in this large cumulated population of studies confirms favorable safety and efficacy of WEB treatment.

We want to thank the correspondents1 for pointing out an error in our article entitled ‘Aneurysm treatment with WEB in the cumulative population of two prospective, multicenter series: 3- year follow-up’2 and JNIS for giving us the opportunity to respond to their critique. First, we must address the error in the legend to Figure 3 in our article.1 2 This legend should read as follows: ‘Unruptured middle cerebral artery aneurysm. (a) DSA (frontal view) prior to intervention. (b) 1-year follow-up radiograph showing retraction of the WEB. (c) 1-year follow-up DSA showing the resulting aneurysm recurrence. (d) and (e) Post-retreatment images performed using stents and coils.’ We are sorry that the previous legend’s text was ambiguous; the images were chosen to show the cause of failure and the retreatment method. We agree that scientific controversies are a necessary part of scientific progress, and uncorrected untruths are not the right way to build new scientific knowledge. Intrasaccular flow disruption with the Woven EndoBridge (WEB) device (Microvention/Sequent, Aliso Viejo, CA, USA) is an innovative treatment in the sense that the concept and the design of the device is new compared with existing endovascular tools. This treatment modality was introduced in Europe (after CE mark) in 2010 for the treatment of complex aneurysms (wide-neck bifurcation aneurysms (WNBAs)) and clinical evaluation started with the WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm Therapy) study (first inclusion in December 2011).3 This evaluation was conducted with the first generation of the device (WEB-DL, dual-layer) and required operators to develop experience during the …

Introduction The intrasaccular flow diversion device WEB is a system used in the treatment of wide necked bifurcation aneurysm. The large number of clinical studies conducted have included mainly unruptured aneurysms. The CLARYS study has been set up to evaluate the efficacy and the safety of the WEB system used to treat bifurcation ruptured aneurysms. Materials and methods The CLARYS study is a prospective, multicenter evaluation conducted in 13 interventional neuroradiological departments in France and Germany. The study design meets the Good Clinical Practice (GCP) standards with data collected in an eDC 100% monitored and endpoints independently evaluated. The primary endpoint is defined as the re-bleeding rate at 1 month post procedure. The secondary endpoints are the rate of adverse events related to the device, the procedure or the disease, the neurological evaluation at 1 month and 1 year based on mRS, the occlusion at 1 year based on the WEB Occlusion Scale (WOS) and the procedure and fluoroscopy time. Results From February 2016 to September 2017, 60 patients (women: 31, 51.7%; mean age: 54.5±1.49 years) with 60 aneurysms were included in the study. The aneurysms locations were at the anterior communicating artery (26/60, 43.3%), the middle cerebral artery bifurcation (23/60, 38.3%), the basilar apex (7/60, 11.7%), the anterior cerebral artery (2/60, 3.3%), the internal carotid artery terminus (1/60, 1.7%) and the posterior communicating artery (1/60, 1.7%). The WEB device was successfully implanted in 56/60 cases (95.0%) The adverse events reported by the sites and adjudicated by the Clinical Event Adjudicator (CEA) were described based on timeline occurrence (per procedure or post procedure), category of events, clinical impact and relationship to device, procedure or disease. The primary endpoint will be presented as well as the morbidity and mortality at 1 month. The 12 months data are under collection so will not be available. Conclusion The study results at 1 month will be presented to address the rate of re bleeding and the safety of the device used in the treatment of ruptured bifurcation aneurysm, following clinical evaluation conducted according to study GCP. Disclosures D. Herbreteau: 2; C; MicroVention. A. Narata: None. R. Bibi: None. L. Ikka: None. C. Mihalea: None. J. Caroff: None. J. Moret: 2; C; MicroVention, Medtronic, Balt. 4; C; Sensome. X. Barreau: None. J. Ferre: None. J. Gauvrit: None. H. Raoult: None. J. Fiehler: 1; C; German Ministry of Science and Education (BMBF), German Ministry of Economy and Innovation (BMWi), German Research Foundation (DFG), European Union (EU), Hamburgische Investitions-und Forderbank (IFB), Medtronic, MicroVention, Philips, Stryker. 2; C; Acandis, Boehringer Ingelheim, Cerenovus, Covidien, Medtronic, Medina, MicroVention, Penumbra, Route 92, Stryker. J. Buhk: 2; C; Sequent, MicroVention. V. Costalat: 2; C; Medtronic, Stryker, Balt, Cerenovus, MicroVention. A. Januel: None. C. Cognard: 2; C; Stryker, MicroVention, Medtronic, Cerenovus. T. Liebig:None. M. Bester: None. H. Desal: None. B. Daumas-Duport: None. R. Bourcier: None. M. Mohlenbruch: None. J. Berkefeld: 2; C; Sequent/MicroVention. R. Du Mesnil de Rochemont: 2; C; Sequent. W. Weber: 2; C; Phenox, MicroVention, Medtronic, Penumbra, Stryker. S. Velasco:None. A. Biondi: None. J. Byrne: 2; C; Oxford Endovascular Ltd. L. Pierot: 2; C; Balt, Cerus Endovascular, MicroVention/Sequent, Phenox, Vesalio, Penumbra.

BACKGROUND AND PURPOSE: Flow disruption with the WEB device is a new technique for the endovascular treatment of wide-neck bifurcation aneurysms. To obtain precise data regarding the safety and efficacy of this treatment with high-quality methodology, the prospective French Observatory study was conducted. Analysis of these data is presented, including 1-year follow-up. MATERIALS AND METHODS: Patients with bifurcation aneurysms for which WEB treatment was indicated were included in this prospective, multicenter Good Clinical Practice study. Clinical data, including adverse events and clinical status at 1 month and 1 year, were collected and independently analyzed by a medical monitor. An independent core laboratory evaluated the anatomic results at 1 year following the procedure. RESULTS: Ten French neurointerventional centers included 62 patients (39 women), 33–74 years of age (mean, 56.6 ± 9.80 years) with 63 aneurysms. Aneurysm locations were the middle cerebral artery in 32 aneurysms (50.8%), anterior communicating artery in 16 (25.4%), basilar artery in 9 (14.3%), and internal carotid artery terminus in 6 (9.5%). Morbidity and mortality at 1 month were, respectively, 3.2% (2/62 patients) and 0.0% (0/62). Morbidity and mortality (unrelated to the treatment) at 1 year were, respectively, 0.0% (0/59) and 3.4% (2/59 patients). At 1 year, complete occlusion was observed in 30/58 aneurysms (51.7%); neck remnant, in 16/58 aneurysms (27.6%); and aneurysm remnant, in 12/58 aneurysms (20.7%). CONCLUSIONS: This prospective French Observatory study showed very good safety of aneurysm treatment with the WEB, with a high rate of adequate aneurysm occlusion at 1 year (79.3%).

Introduction Cerebral vasospasm is the leading cause of morbidity and mortality in patients with aneurysmal subarachnoid haemorrhage (SAH) surviving the initial ictus. Commonly used techniques for vasospasm assessment are digital subtraction angiography and transcranial Doppler sonography. These techniques can reliably identify only the major vessel spasm and fail to estimate its haemodynamic significance. To overcome these issues and to enable comprehensive non-invasive assessment of vasospasm inside the interventional suite, a novel protocol involving measurement of parenchymal blood volume (PBV) using C-arm flat detector computed tomography (FDCT) was implemented. Materials and methods Patients from the neuro-intensive treatment unit (ITU) with suspected vasospasm following aneurysmal SAH were scanned with a biplane C-arm angiography system using an intravenous contrast injection protocol. The PBV maps were generated using prototype software. Contemporaneous clinically indicated MR scan including the diffusion- and perfusion-weighted sequences was performed. C-arm PBV maps were compared against the MR perfusion maps. Results Distribution of haemodynamic impairment on C-arm PBV maps closely matched the pattern of abnormality on MR perfusion maps. On visual comparison between the two techniques, the extent of abnormality indicated PBV to be both cerebral blood flow and cerebral blood volume weighted. Conclusion C-arm FDCT PBV measurements allow an objective assessment of the severity and localisation of cerebral hypoperfusion resulting from vasospasm. The technique has proved feasible and useful in very sick patients after aneurysmal SAH. The promise shown in this early study indicates that it deserves further evaluation both for post-SAH vasospasm and in other relevant clinical settings.

BACKGROUND AND PURPOSE: C-arm flat detector CT parenchymal blood volume imaging allows functional assessment of the brain parenchyma in the neurointerventional suite. This study aimed to determine the optimal C-arm flat detector CT parenchymal blood volume thresholds for demarcating irreversibly infarcted brain parenchyma by using areas of restricted diffusion on MR imaging as a surrogate marker for infarction. MATERIALS AND METHODS: Twenty-six patients with delayed cerebral ischemia following aneurysmal SAH underwent research C-arm CT parenchymal blood volume scans by using a biplane angiography system and contemporaneous MR imaging. Infarct and peri-infarct tissue VOIs and their homologous VOIs in the contralateral uninvolved hemisphere were delineated on the basis of the review of DWI, PWI, and ADC images. Voxel-based receiver operating characteristic curve analysis was performed to estimate the optimal absolute and normalized parenchymal blood volume values for demarcating the infarct voxels. RESULTS: For 12 patients with areas of restricted diffusion (infarct volume, 6.38 ± 7.09 mL; peri-infarct tissue volume, 22.89 ± 21.76 mL) based on the voxel-based receiver operating characteristic curve analysis, optimal absolute and normalized parenchymal blood volume thresholds for infarction were 2.49 mL/100 g (area under curve, 0.76; sensitivity, 0.69; specificity, 0.71) and 0.67 (area under curve, 0.77; sensitivity, 0.69; specificity, 0.72), respectively (P value < .01). For the moderate-to-severely ischemic peri-infarct zone, mean parenchymal blood volume values of the involved hemisphere VOIs were lower compared with the uninvolved hemisphere VOIs (P value < .01). However, for the mild-to-moderately ischemic peri-infarct zone, there was no statistically significant difference between the mean parenchymal blood volume values of the involved and uninvolved hemisphere VOIs (P value > .05). CONCLUSIONS: C-arm flat detector CT parenchymal blood volume maps in conjunction with optimal thresholds are sensitive and specific for the estimation of irreversibly infarcted parenchyma. Parenchymal blood volume maps allow reliable detection of moderate-to-severe ischemia; however, the potential for underestimation of mild-to-moderate ischemia exists.

Purpose: WEB Flow disruption is an innovative endovascular treatment for wide-neck bifurcation aneurysms. Safety and efficacy are analyzed in the cumulated population of 3 prospective multicenter GCP (Good Clinical Practice) studies conducted in Europe (WEBCAST, French Observatory, WEBCAST2). Methods: Patients with wide neck bifurcation aneurysms were included in these 3 studies. An independent medical monitor independently analyzed adverse events. An independent expert in Interventional Neuroradiology evaluated anatomical results at 12 months using the 3 grades scale: complete occlusion, neck remnant, and aneurysm remnant. Results: A total of 168 patients with 169 aneurysms including 14 ruptured (8.3%) were included in the 3 studies. Eighty-six out 169 aneurysms were located at middle cerebral artery (50.9%), 36/169 at anterior communicating artery (21.3%), 30/169 at basilar artery (17.8%), and 17/169 at internal carotid artery terminus (10.1%). Placement of the WEB device was feasible in 163/169 aneurysms (96.4%). Morbidity and mortality at one month were reported in 4/168 patients (2.4%) and 0/168 patients (0.0%), respectively. Anatomical results at 12 months were complete aneurysm occlusion in 82/149 aneurysms (55.0%), neck remnant in 38/149 aneurysms (25.5%), and aneurysm remnant in 29/149 aneurysms (19.5%). Conclusion: This analysis in the large cumulated population of 3 GCP studies confirms the high safety of WEB treatment with low morbidity and mortality. At 12 months, adequate occlusion (complete occlusion and neck remnant) was obtained in a high percentage of aneurysms (80.5%).

These lesions comprise arteriovenous fistulas situated in the meninges and supplied partly or wholly by dural arteries. Venous drainage is to dural sinuses and/or leptomeningeal venous channels.

There are few topics in the field of endovascular neurosurgery as challenging as the management of patients with arteriovenous malformations of the brain. In line with other tutorials, which focus on a particular diagnosis, this tutorial describes pathology, clinical findings, diagnosis and treatments in a logical sequence. The emphasis is on optimising treatment for the affected individual. Diagnosis is a crucial part of the process and because of the variety of lesions and the importance of individual phenotype, advice to patients about intervention is now usually generated through multidisciplinary team discussions. The endovascular therapist thus needs to know the latest research findings in addition to being able to perform endovascular embolisation. This tutorial explains the importance of accurate imaging in defining a lesion’s angio-architecture and how this dictates treatment strategy. It also explains the controversies around our understanding of these complex lesions, so that patient advice can be appropriate and based on current guidelines.

The distal venous drainage of the head is through the jugular veins, vertebral veins and the inferior thyroid veins which drain to the brachiocephalic or subclavian veins. These receive the venous drainage of the veins of the face and neck, which for description can be divided into deep and superficial drainage systems or into anterior-to-posterior territories. The following description is a mix, and the reader is invited to use the diagrams to mentally assemble the described pathways into their coherent reality of interconnecting valveless channels. They will be described in groups based on the main veins. These do not fit easily into anatomical areas but collect definable tributaries before reaching the base of the neck. Their relative position will be from proximal to distal in the most consistent direction of blood flow (i.e. towards the heart).

In this tutorial spinal vascular malformations are defined and separated into spinal dural arteriovenous fistula, intradural perimedullary fistula and intramedullary spinal cord arteriovenous malformation. The reader is then taken through a detailed description of the aetiology, pathology, natural history, imaging and endovascular treatment techniques for each type. The clinical features and background literature associated with these lesions is explained, and the trainee is provided with protocols for performing spinal angiography for their diagnosis or exclusion. Other rare vascular lesions of the spine, including metameric syndromes, cavernous malformation and aneurysms are described, to complete a comprehensive review of spinal lesions relevant to the practice of endovascular neurosurgery and interventional neuroradiology.

The radiculospinal arteries supply the spinal cord and its nerve roots. These arteries were termed ‘radicular’, ‘radiculopial’ and ‘radiculomedullary’ by Tanon [1] because they individually provide one of three types of supply to the neural tissue. The radicular artery supplies nerve roots only; the radiculopial artery supplies nerve root and pial plexus (white matter), and the radiculomedullary artery supplies roots, pial plexus and cord medulla (grey matter).

The best available classification of this complex group is the biological description of lesions of infants and children published by Mulliken and Glowacki in 1982 [1]. This exemplifies the best in clinicopathological classifications and can be applied to vascular lesions of the head and neck in all ages. It is based on cellular features and correlated with clinical findings and natural history. It separates two main biologically different lesion types: haemangiomas and vascular malformations (Table 14.1). This chapter will refer extensively to the subtypes it defines. Mulliken and Glowacki classification [1] has stood the test of time and was adopted by the International Society for the Study of Vascular Anomalies in 1996. It is widely used as the basis for describing a group of conditions, often characterised by a ‘birthmark’. A minor modification was proposed in 1988 [2] which additionally divided vascular malformations into low- and high-flow lesions (Table 14.2).

Epistaxis is common. At least 60% of us will have episodes of nose bleeding at some time [2]. These occur with peak incidences in children ( 50 years). Only 6% of episodes require medical treatment, and these are usually in the older age group. Bleeding can arise from veins, arteries or arterialised veins (e.g. associated with a vascular malformation or an arteriovenous shunt). Most episodes are idiopathic, though epistaxis in adults is frequently associated with systemic hypertension and other medical comorbidities.

A carotid cavernous fistula (CCF) consists of an abnormal connection between the cavernous segment of the internal carotid artery (ICA) and the cavernous sinus. The resulting high-flow shunt raises pressure in the drainage pathways of the cavernous sinuses and causes symptoms due to venous hypertension in the orbit, cortical or deep cerebral veins and venous stenosis due to secondary hyperplasia. It is the most frequent location of direct intracranial arteriovenous fistulas and the majority are caused by trauma. Spontaneous fistulas are caused by rupture of an aneurysm of the cavernous ICA or other arterial diseases that weakens the wall. The connection is usually a single hole or less frequently a small number of individual holes. The point of rupture in the arterial wall is often large (1–10 mm) and spontaneous cure is therefore rare. Including this condition in a classification of angiographic patterns in dural arteriovenous malformations of the cavernous sinus region [1] is confusing the two conditions and adds little to their understanding or management.

Infants and children presenting with the vein of Galen malformation is a situation that an endovascular neurosurgeon is likely to encounter in their practice but not sufficiently often to develop the specialist skills for comprehensive management. This tutorial is tailored to give the reader an overview of management and specifically the knowledge needed for diagnosis, preliminary discussions with parents and follow-up support. In the UK this is sufficient for most practitioners since generally patients are referred on to specialist centres for interventions. In many other countries, referral to a special paediatric centre may not be an option so the principles of clinical assessment, timing of intervention and embolisation techniques are described. The background literature and classification of angiographic types are covered and the tutorial includes a discussion of non-Galenic arteriovenous fistulas because of similarities in their endovascular management with the vein of Galen malformation.

In this tutorial embolisation of tumours is first considered in general terms and then how it is applied to specific tumour types. A generic description guides the reader though the process of selection and pre-procedure assessments needed to achieve successful tumour devascularisation. The therapeutic aims dictated by histology and tumour locations are discussed and how they determine the assessment of risks and benefits prior to embolisation explained. Procedure techniques, precautions and post-procedure patient care are covered. The tutorial then takes the reader through the application of these principles to the commonly treated pathologies of the head and neck region, namely, meningioma, juvenile nasopharyngeal angiofibroma and paraganglioma. Other cranial and spinal tumours likely to be referred for embolisation are described in less detail but maintaining the same emphasis on the need to plan endovascular treatments and set achievable outcome goals for all interventions.

Introduction: This study assessed volume changes of unruptured large and giant aneurysms (greatest diameter >20 mm) after treatment with flow diverter (FD) stents. Methods: Clinical audit of the cases treated in a single institution, over a 5-year period. Demographic and clinical data were retrospectively collected from the hospital records. Aneurysm volumes were measured by manual outlining at sequential slices using computerised tomography (CT) or magnetic resonance (MR) angiography data. Results: The audit included eight patients (seven females) with eight aneurysms. Four aneurysms involved the cavernous segment of the internal carotid artery (ICA), three the supraclinoid ICA and one the basilar artery. Seven patients presented with signs and symptoms of mass effect and one with seizures. All but one aneurysm was treated with a single FD stent; six aneurysms were also coiled (either before or simultaneously with FD placement). Minimum follow-up time was 6 months (mean 20 months). At follow-up, three aneurysms decreased in size, three were unchanged and two increased. Both aneurysms that increased in size showed persistent endosaccular flow at follow-up MR; in one case, failure was attributed to suboptimal position of the stent; in the other case, it was attributed to persistence of a side branch originating from the aneurysm (similar to the endoleak phenomenon of aortic aneurysms). At follow-up, five aneurysms were completely occluded; none of these increased in volume. Conclusion: Complete occlusion of the aneurysms leads, in most cases, to its shrinkage. In cases of late aneurysm growth or regrowth, consideration should be given to possible endoleak as the cause. © 2013 Springer-Verlag Berlin Heidelberg.

Objective The frequency and the degree of recovery of anterior pituitary hormone deficits in patients with macroprolactinoma responsive to cabergoline are not clear. Our aim was to evaluate pituitary function in these patients with particular reference to an assessment of the possible restoration of pituitary deficits. Subjects and Methods The records of all subjects prospectively presenting to our Department with macroprolactinomas treated with cabergoline over a 2-year period were reviewed. Pituitary function was assessed at diagnosis and, if abnormal, for three consecutive years for the GH, FSH/LH and ACTH axes, and at 3 years for the TSH axis. Results Twelve patients were included. Severe GH deficiency was found in 83% at diagnosis and did not resolve in any patient at last assessment. Gonadotrophin deficiency was found in 90% at diagnosis and in 50% at last evaluation (showing reversal in 44% of deficient patients, all achieved within 1 year). ACTH deficiency was found in 17% at diagnosis and it did not reverse in any patient at last assessment. TSH deficiency was found in 36% at diagnosis and in 27% at last assessment (reversal in 25% of deficient patients). Conclusions In our study, in a group of patients with macroprolactinoma systematically assessed at intervals, pituitary dysfunction in response to cabergoline was found to be mostly irreversible, except for the gonadotroph axis which showed restoration in a subset of subjects following achievement of normoprolactinaemia. It would appear that the reversibility of pituitary axes may be less common than previously thought. © 2012 John Wiley and Sons Ltd.

Context Despite the major risk of regrowth of clinically nonfunctioning pituitary adenomas (CNFAs) after primary treatment, systematic data on the probability of further tumor progression and the effectiveness of management approaches are lacking. Objective To assess the probability of further regrowth(s), predictive factors, and outcomes of management approaches in patients with CNFA diagnosed with adenoma regrowth after primary treatment. Patients, design, and setting Retrospective cohort study of 237 patients with regrown CNFA managed in two UK centers. Results Median follow-up was 5.9 years (range, 0.4 to 37.7 years). The 5-year second regrowth rate was 35.3% (36.2% after surgery; 12.5% after radiotherapy; 12.7% after surgery combined with radiotherapy; 63.4% with monitoring). Of those managed with monitoring, 34.8% eventually were offered intervention. Type of management and sex were risk factors for second regrowth. Among those with second adenoma regrowth, the 5-year third regrowth rate was 26.4% (24.4% after surgery; 0% after radiotherapy; 0% after surgery combined with radiotherapy; 48.3% with monitoring). Overall, patients with a CNFA regrowth had a 4.4% probability of a third regrowth at 5 years and a 10.0% probability at 10 years; type of management of the first regrowth was the only risk factor. Malignant transformation was diagnosed in two patients. Conclusions Patients with regrown CNFA after primary treatment continue to carry considerable risk of tumor progression, necessitating long-term follow-up. Management approach to the regrowth was the major factor determining this risk; monitoring had >60% risk of progression at 5 years, and a substantial number of patients ultimately required intervention.

Cerebral aneurysm (CA) is a localised dilatation in the wall of the brain vasculature which can cause it to swell out like a balloon. If not treated, it will continue to grow and eventually tear or rupture, resulting in severe disability from stroke and, in around 25% of cases, death [1]. CAs affect up to 5% of the adult population with 1% of detected aneurysms rupture every year [2].

This tutorial will cover the types of intracranial haemorrhage, their appearances on CT and MRI and their causes. The term haemorrhagic stroke is used to distinguish acute bleeding from brain dysfunction due to ischaemic stroke and cerebral infarction. Stroke is a common reason for scanning patients and the most likely reason for a patient with spontaneous intracranial bleeding being referred for imaging. Teaching will focus on this indication but include other causes of spontaneous intracranial haemorrhage and the diagnosis (or exclusion) of a causative vascular pathology.

Context The optimal duration of dopamine agonist (DA) therapy in prolactinoma is unknown. There are concerns that despite low recurrence rates in highly selected groups, high recurrence rates after DA withdrawal may occur in routine practice. Objective To explore recurrence of hyperprolactinaemia and predictive factors following DA withdrawal in patients with microprolactinoma and macroprolactinoma. Design A retrospective study on adult patients with confirmed prolactinoma attending the Oxford Endocrine Department. Patients and Measurements We identified patients with macroprolactinoma (n = 15) and microprolactinoma (n = 45) treated with DA therapy for >3 years, with a trial off DA therapy. None had other treatments. Measurements included recurrence of hyperprolactinaemia following DA withdrawal, tumour size (macroprolactinomas), duration of DA therapy, prolactin levels (baseline, during DA therapy, recurrence) and time to recurrence. Data were reported as mean (range). Results During DA therapy, prolactin levels suppressed to normal range in all patients with macroprolactinoma and microprolactinoma, and most macroprolactinomas (n = 14) had substantial tumour shrinkage. Hyperprolactinaemia recurred in 93% of macroprolactinomas (n = 14) at 8·8 months (3–36) and 64% of microprolactinomas (n = 29) at 4·8 months (3–12). Duration of DA therapy was 7·5 years (4–15) for macroprolactinomas and 4·1 years (3–10) for microprolactinomas. Prolactin levels during DA therapy were 144 mU/l (7–336) for macroprolactinomas and 278 mU/l (30–629) for microprolactinomas. For microprolactinomas, prolactin levels during DA therapy were less suppressed in those with recurrence than in those without recurrence (P < 0·05). Conclusions In routine practice, hyperprolactinaemia recurs early in most macroprolactinomas (93%) and microprolactinomas (64%) following DA therapy discontinuation. For most macroprolactinomas, cessation of DA cannot be recommended even after 7 years of therapy.

Introduction: Flow diverter (FD) devices have emerged as an alternative treatment for a subgroup of intracranial aneurysms. The principle of endovascular flow diversion is inherently different from endosaccular coil embolisation. To monitor the angiographic outcomes for FDs, a sensitive and reliable new measure is required. Oxford Neurovascular and Neuroradiology Research Unit developed a grading schema while conducting a registry to audit outcomes of patients treated using a particular FD (SILK flow diverter; Balt Extrusion, Montmorency, France). The aim of this study is to assess the applicability and reproducibility of the new schema. Methods: The proposed grading schema is designed for saccular- or fusiform-shaped aneurysms. For both, it documents the degree of aneurysm occlusion using a five-point scale and the parent artery patency on a three-point scale. Two neuroradiologists used the schema to independently rate 55 angiograms showing comparable treatment and follow-up angiograms of patients treated with a FD. Inter-observer agreement was estimated using the weighted kappa co-efficient. Results: Both readers found the schema easy to apply. Overall, there were ten discordant readings for degrees of aneurysm occlusion and two for parent artery patency. Inter-observer agreement was excellent for both the assessment of aneurysm occlusion (k=0.89; C.I.=0.81-0.99) and parent artery patency (k=0.90; C.I.=0.76-1.0). Conclusion: The proposed schema is sufficiently sensitive to register gradual aneurysm occlusion and parent artery patency on interval angiograms. It is reproducible and is applicable to both saccular and fusiform aneurysms. More data on follow-up of FD-treated aneurysms is needed to prove its efficacy in predicting the long-term behaviour of treated aneurysms. © 2010 Springer-Verlag.

BACKGROUND AND PURPOSE: Exercise is an accepted method of improving cardiovascular health; however, the impact of increases in blood flow and heart rate on a cerebral aneurysms is unknown. This study was performed to simulate the changes in hemodynamic conditions within an intracranial aneurysm when a patient exercises. MATERIALS AND METHODS: Rotational 3D digital subtraction angiograms were used to reconstruct patient-specific geometries of 3 aneurysms located at the bifurcation of the middle cerebral artery. CFD was used to solve for transient flow fields during simulated rest and exercise conditions. Inlet conditions were set by using published transcranial Doppler sonography data for the middle cerebral artery. Velocity fields were analyzed and postprocessed to provide physiologically relevant metrics. RESULTS: Overall flow patterns were not significantly altered during exercise. Across subjects, during the exercise simulation, time-averaged WSS increased by a mean of 20% (range, 4%–34%), the RRT of a particle in the near-wall flow decreased by a mean of 28% (range, 13%–40%), and time-averaged pressure on the aneurysm wall did not change significantly. In 2 of the aneurysms, there was a 3-fold order-of-magnitude spatial difference in RRT between the aneurysm and surrounding vasculature. CONCLUSIONS: WSS did not increase significantly during simulated moderate aerobic exercise. While the reduction in RRT during exercise was small in comparison with spatial differences, there may be potential benefits associated with decreased RRT (ie, improved replenishment of nutrients to cells within the aneurysmal tissue).

The clinical treatment of cerebral aneurysms, from detection to post-intervention follow-up care, poses a series of challenges, both clinical and technical. The introduction of computational simulation techniques, in all stages of the procedure, allows for, or promises to provide, patient-specific risk evaluation, rationalisation and optimisation of surgical or interventional planning and a priori evaluation of treatment efficacy and long-term outcome. In this article, we present techniques that allow for the simulation of growth of cerebral aneurysms, based on detailed vascular wall remodelling techniques. Moreover, we demonstrate that computational techniques allow the preinterventional evaluation of the effectiveness of detachable coil implantation. Finally, appropriate coupling of the haemodynamics of flow with thrombosis models allows for the prediction of the growth of clot; of great importance both of the eventual healing of the lesion in case of endovascular coil treatment for cerebral aneurysms but also as an indicator of the spontaneous formation of microembolic clots. © 2009 Taylor and Francis.

BACKGROUND AND PURPOSE: The major goal of acute ischemic stroke treatment is fast and sufficient recanalization. Percutaneous transluminal balloon angioplasty (PTA) and/or placement of a stent might achieve both by compressing the thrombus at the occlusion site. This study assesses the feasibility, recanalization rate, and complications of the 2 techniques in an animal model. MATERIALS AND METHODS: Thirty cranial vessels of 7 swine were occluded by injection of radiopaque thrombi. Fifteen vessel occlusions were treated by PTA alone and 15, by placement of a stent and postdilation. Recanalization was documented immediately after treatment and after 1, 2, and 3 hours. Thromboembolic events and dissections were documented. RESULTS: PTA was significantly faster to perform (mean, 16.6 minutes versus 33.0 minutes for stent placement; P < .001), but the mean recanalization rate after 1 hour was significantly better after stent placement compared with PTA alone (67.5% versus 14.6%, P < .001). Due to the self-expanding force of the stent, vessel diameter further increased with time, whereas the recanalization result after PTA was prone to reocclusion. Besides thromboembolic events related to the passing maneuvers at the occlusion site, no thrombus fragmentation and embolization occurred during balloon inflation or stent deployment. Flow to side branches could also be restored at the occlusion site because it was possible to direct thrombus compression. CONCLUSIONS: Stent placement and postdilation proved to be much more efficient in terms of acute and short-term vessel recanalization compared with PTA alone.

Object Microarteriovenous malformations (micro-AVMs) are an uncommon subgroup of brain AVMs defined by a nidus measuring < 1 cm in diameter. The clinical features, angiographic characteristics, and outcomes in patients with micro-AVMs who had been treated endovascularly after presenting with hemorrhage were reviewed to identify common features affecting prognosis. Methods Between 1997 and 2006, 25 patients (12 females and 13 males) with 26 micro-AVMs were treated. Twenty-four patients presented with intracerebral hematoma and 1 with subarachnoid hemorrhage only. All patients underwent CT on admission, diagnostic cerebral angiography, and 1 session of endovascular treatment during the acute phase. Results Procedure-related complications occurred in 3 patients (12%), which caused temporary hemiparesis in 1 (4%) and no clinical sequelae in 2 patients (8%). Complete nidus obliteration was achieved at the end of the embolization in 22 (84.6%) of 26 lesions. Two recurrences were evident on follow-up angiography 6 months postembolization, resulting in a complete obliteration rate of 77% (20 of 26 lesions) after a single treatment. Late angiography was performed in 12 patients, and no further recurrences were identified. Conclusions Immediate complete obliteration of a micro-AVM with a high permanent cure and low morbidity rates was accomplished using endovascular treatment. Early embolization after bleeding should be considered as an alternative to resection.

INTRODUCTION: Idiopathic ruptured aneurysms of distal cerebellar arteries (DCAAs) are rare, and their endovascular therapy (EVT) has as yet not been extensively reported. They are usually assumed to result from local arterial wall disruption rather than infection, unlike distal supratentorial artery aneurysms. This study was performed to audit their frequency, potential aetiology and results of EVT. PATIENTS AND METHODS: Using strict inclusion criteria and a database of 1715 EVT patients, we identified ten idiopathic ruptured DCAAs (0.6%) over a 13-year period (1993-2006). The series comprised six males and four females with mean age of 64 years and solitary aneurysms located on posterior inferior cerebellar artery (five patients), anterior inferior cerebellar artery (three patients) and superior cerebellar artery (two patients). Nine aneurysms were fusiform and were treated by endovascular parent artery occlusion, and one was saccular and treated by endosaccular packing. Endovascular therapy was performed with coils in seven cases, n-butyl-2-cyanoacrylate (NBCA) in two cases and with both in one case. RESULTS: Primary EVT was successful in eight patients. One patient died following a procedure-related re-bleeding and one patient required re-treatment after failed endosaccular packing. Nine patients made good or excellent clinical recoveries (modified Rankin Scale 2 or less). Focal cerebellar infarctions were seen on computed tomography images after EVT in three patients, only one of whom was symptomatic with transient dysmetria, which resolved completely during follow up. No aneurysm recanalisation was detected on late follow-up imaging up to 24 months. CONCLUSION: Ruptured DCAAs are rare. The majority are fusiform in shape and their aetiology remains uncertain. Endovascular treatment is feasible and effective. It usually requires parent artery occlusion.

We present the first case of successful non-surgical treatment of an internal carotid aneurysm, embedded within a macroprolactinoma. A 53 year old male, with a previous history of Non-Hodgkin's Lymphoma (NHL), presented with severe right sided frontal headache, decreased visual acuity, and ophthalmolplegia due to a third nerve palsy. A CT scan showed a 4.6 by 4.8 cm mass in the pituitary fossa with bony erosion. Initially, it was thought to be a cerebral recurrence of the Non-Hodgkin's disease. Direct questioning revealed a long history of erectile dysfunction with loss of libido. Prolactin at presentation was 537, 200 mU/l and a diagnosis of macroprolactinoma, with apoplexy was made. A subsequent MRI brain confirmed a large macroadenoma with an intra cavernous aneurysm encased by the tumour. A therapeutic dilemma ensued due to the need for urgent decompression of the visual pathways, preferably by surgery. However, in the presence of an intrasellar aneurysm, surgery would have been extremely hazardous. The patient was therefore commenced on cabergoline and rapidly titrated up to 4 mg per week. The aneurysm was treated by endovascular occlusion of the right carotid artery under radiological control. The combination of these therapies, without conventional surgical intervention, resulted in resolution of the third nerve palsy and recovery of visual acuity in the left eye. The diagnosis and management of this condition was challenging and the final outcome, with non-surgical treatment and carotid artery occlusion was satisfactory.

Background and Purpose— Because the long-term security of endovascular treatments remains uncertain, a follow-up study of the patients treated in the International Subarachnoid Aneurysm Trial was performed to compare the frequency, timing, and consequences of aneurysm recurrence. Methods— Patient data were reclassified by actual treatment performed. Aneurysm and patient characteristics, including occlusion grades, time and type of retreatment, and clinical outcomes, were compared. The relationship between these variables and late retreatment as a surrogate for recurrence was analyzed by means of the Cox proportional hazards model. Results— Retreatment was performed in 191 of 1096 (17.4%) patients after primary endovascular coiling (EVT) and in 39 of 1012 patients (3.8%) after neurosurgical clipping. After EVT, 97 (8.8%) patients were retreated early and 94 (9.0%) late, 7 (0.6%) after rebleeding and 87 (8.3%) without. The mean time to late retreatment was 20.7 months. After neurosurgical clipping, 30 (2.9%) patients were retreated early and 9 (0.85%) late, 3 (0.3%) after rebleeding and 6 (0.6%) without. The mean time to late retreatment was 5.7 months. The hazard ratio (HR) for retreatment after EVT was 6.9 (95% CI=3.4 to 14.1) after adjustment for age ( P =0.001, HR=0.97, 95% CI=0.95 to 0.98), lumen size ( P =0.006, HR=1.1, 95% CI=1.03 to 1.18), and incomplete occlusion ( P Conclusions— Late retreatment was 6.9 times more likely after EVT. Younger age, larger lumen size, and incomplete occlusion were risk factors for late retreatment after EVT. After neurosurgical clipping, retreatments were earlier; whereas EVT retreatments continued to be performed throughout the follow-up period. Short-term follow-up imaging is therefore insufficient to detect recurrences after EVT.

ObjectiveNon-functioning pituitary adenomas (NFAs) have a prevalence of 7–22/100 000 people. A significant number of patients suffer from morbidities related to the tumor, possible recurrence(s), and treatments utilized. Our aim was to assess mortality of patients with macroNFA and predictive factors.DesignRetrospective cohort study in a tertiary referral center in the UK.MethodsA total of 546 patients operated for a macroNFA between 1963 and 2011 were studied. Mortality data were retrieved through the National Health Service Central Register and hospital records and recorded as standardized mortality ratio (SMR). Mortality was estimated for the total and various subgroups with clinical follow-up data.ResultsMedian follow-up was 8 years (range: 1 month–48.5 years). SMR was 3.6 (95% CI, 2.9–4.5), for those operated before 1990, 4.7 (95% CI, 2.7–7.6) and for those after 1990, 3.5 (95% CI, 2.8–4.4). Main causes of death were cardio/cerebrovascular (33.7%), infections (30.1%), and malignancy (28.9%). Cox regression analysis demonstrated that only age at diagnosis remained an independent predictor of mortality (hazard ratio 1.10; 95% CI, 1.07–1.13, PConclusionsDespite the improvement of treatments over the last three decades, the mortality of patients with NFAs in our series remains high. Apart from age, factors related with the management/outcome of the tumor are not independent predictors, and pituitary hormone deficits managed with the currently-used substitution protocols do not adversely affect mortality.

Introduction C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) imaging in the neuro-interventional suite is a new technique for which detailed whole brain measurements have not been previously reported. This study aims to create a catalogue of PBV measurements for various anatomical regions encompassing the whole brain, using a three-dimensional volume-of-interest (3D-VOI) analysis. Methods We acquired and analysed 30 C-arm FDCT datasets from 26 patients with aneurysmal subarachnoid haemorrhage (SAH), as part of a prospective study comparing C-arm computed tomography (CT) PBV with magnetic resonance perfusion-weighted imaging (MR-PWI). We calculated the PBV values for various brain regions with an automated analysis, using 58 pre-defined atlas-based 3D-VOIs encompassing the whole brain. VOIs partially or completely overlapping regions of magnetic resonance diffusion weighted imaging (MR-DWI) abnormality or magnetic resonance cerebral blood flow (MR-CBF) asymmetry were excluded from the analysis. Results Of the 30 C-arm CT PBV datasets, 14 (54%; 12 patients) had areas of restricted diffusion, the majority of which were focal. The PBV values for the cerebral cortex and cerebral white matter were 4.01 ± 0.47 (mean ± SD) and 3.01 ± 0.39 ml per 100 ml. Lobar PBV values were: frontal lobe 4.2 ± 0.8, temporal lobe 4.2 ± 0.9, parietal lobe 3.9 ± 0.7 and occipital lobe 4.3 ± 0.8 ml/100 ml. The basal ganglia and brainstem PBV values were 3.4 ± 0.7 and 4.6 ± 0.6 ml/100 ml, respectively. Conclusions Compared with the typical reference cerebral blood volume (CBV) values reported in the literature for Positron Emission Tomography (PET), the PBV values were relatively high for the white matter and relatively low for the cortical grey matter. The reported catalogue of PBV values for various brain regions would be useful to inform future studies and could be used in clinical practice, when interpreting PBV maps.

Although bariatric surgery is highly effective in reducing total body fat, Roux-en-Y gastric bypass (RYGB) proportionally reduces abdominal visceral fat more than laparoscopic adjustable gastric banding (LAGB) [(1)][1]. Because visceral fat depots are more strongly linked to increased

Purpose WEB Flow disruption is an innovative endovascular treatment for wide-neck bifurcation aneurysms. Three prospective multicenter GCP (Good Clinical Practice) studies were conducted in Europe (WEBCAST, French Observatory, WEBCAST2). Safety and efficacy data are analyzed in the cumulated population of these 3 studies. Methods Patients with wide neck bifurcation aneurysms were included in these 3 studies. An independent medical monitor independently analyzed adverse events. Follow-up imaging was obtained at 6 and 12 months in WEBCAST study and at 12 months in French Observatory. An independent expert in Interventional Neuroradiology evaluated anatomical results using the 3 grades scale: complete occlusion, neck remnant, and aneurysm remnant. In WEBCAST, the reader was also directly comparing evolution of anatomical results between 6 months and 12 months classified as improved, stable, or worsened. Results A total of 168 patients (112 females, 66.7%) with 169 aneurysms including 14 ruptured (8.3%) were included in the 3 studies (51 patients in WEBCAST, 62 in French Observatory, and 55 in WEBCAST2). Eighty-six out 169 aneurysms were located at middle cerebral artery (50.9%), 36/169 at anterior communicating artery (21.3%), 30/169 at basilar artery (17.8%), and 17/169 at internal carotid artery terminus (10.1%). Placement of the WEB device was feasible in 163/169 aneurysms (96.4%). Morbidity and mortality at one month were reported in 4/168 patients (2.4%) and 0/168 patients (0.0%), respectively. At 6 months, morbidity and mortality were reported in 1/99 patients (1.0%) and 3/99 patients (3.0%), respectively (there was no follow-up at 6 months in French Observatory). Anatomical results at 6 months (WEBCAST and WEBCAST2) were complete aneurysm occlusion in 51/90 aneurysms (56.6%), neck remnant in 23/90 aneurysms (25.5%), and aneurysm remnant in 16/90 aneurysms (16.7%). Anatomical results at 12 months (WEBCAST and French Observatory) were complete aneurysm occlusion in 56/100 aneurysms (56.0%), neck remnant in 26/100 aneurysms (26.0%), and aneurysm remnant in 18/100 aneurysms (18.0%). Conclusion This analysis in the large cumulated population of 3 GCP studies confirms the high safety of WEB treatment with low morbidity and mortality at one month and 6 months. At 6 and 12 months, adequate occlusion (complete aneurysm occlusion and neck remnant) was obtained in a high percentage of aneurysms (82.2% and 82.0%, respectively). Disclosures L. Pierot: 2; C; Sequent. A. Molyneux: 2; C; Sequent. J. Byrne: 2; C; Sequent.

We propose a new method for aligning three-dimensional (3-D) magnetic resonance angiography (MRA) with 2-D X-ray digital subtraction angiograms (DSA). Our method is developed from our algorithm to register computed tomography volumes to X-ray images based on intensity matching of digitally reconstructed radiographs (DRRs). To make the DSA and DRR more similar, we transform the MRA images to images of the vasculature and set to zero the contralateral side of the MRA to that imaged with DSA. We initialize the search for a match on a user defined circular region of interest. We have tested six similarity measures using both unsegmented MRA and three segmentation variants of the MRA. Registrations were carried out on images of a physical neuro-vascular phantom and images obtained during four neuro-vascular interventions. The most accurate and robust registrations were obtained using the pattern intensity, gradient difference, and gradient correlation similarity measures, when used in conjunction with the most sophisticated MRA segmentations. Using these measures, 95% of the phantom start positions and 82% of the clinical start positions were successfully registered. The lowest root mean square reprojection errors were 1.3 mm (standard deviation 0.6) for the phantom and 1.5 mm (standard deviation 0.9) for the clinical data sets. Finally, we present a novel method for the comparison of similarity measure performance using a technique borrowed from receiver operator characteristic analysis.

Objective We sought to determine the incidence of seizures among patients treated with endovascular coil embolization for ruptured intracranial aneurysms because data on which to base antiepileptic drug (AED) prescriptions and advice to patients regarding driving motor vehicles and other high-risk activities are currently lacking. Methods We conducted a single-institute, single-operator observational study of 243 patients referred for endovascular treatment after aneurysmal subarachnoid hemorrhage. Prospective data collection was performed, and all successfully treated patients were followed. The incidence of seizures was compared with published surgical data, and logistic regression analysis of potential clinical associations was performed. Patients were followed for up to 7.7 years (mean follow-up period, 21.9 mo). Results Ictal seizures occurred at the time of subarachnoid hemorrhage in 26 (11%) of 243 patients and correlated with middle cerebral artery aneurysm location, loss of consciousness at ictus, and AED prescription. No patients experienced periprocedural seizures during their hospitalization. Seven of 233 successfully treated patients (3%) experienced seizures more than 30 days after treatment: late seizures occurred de novo in four patients (1.7%) and in three patients (1.4%) were caused by preexisting epilepsy. Two patients (0.85%) who had de novo seizures developed epilepsy. Late seizures correlated with a history of previous seizures, the presence of a cerebrospinal fluid shunt, and the use of AEDs. Conclusion The low incidence of seizures does not justify the use of prophylactic AED therapy after aneurysmal subarachnoid hemorrhage in patients treated solely with coil embolization, nor does it justify subsequent restrictions on the driving of motor vehicles if the patient is otherwise fit to drive.

Introduction Si le traitement endovasculaire par coiling est desormais la premiere option therapeutique dans la prise en charge des anevrismes intracrâniens, cette approche presente encore certaines limites, notamment pour les anevrismes a collet large. Ceci a conduit au developpement de nouvelles techniques endovasculaires ( remodelling , stenting , flow diversion ). Le traitement par des dispositifs intra-anevrismaux de type WEB represente une approche nouvelle qui consiste a alterer le flux intra-anevrismal et a induire une thrombose au sein du sac. Trois etudes prospectives, multicentriques, respectant les bonnes pratiques cliniques ont ete conduites en France et en Europe (WEBCAST, French Observatory, WEBCAST2) et les donnees de securite et d’efficacite dans la population cumulee de ces 3 etudes sont analysees. Materiels et methodes Les patients porteurs d’un anevrisme de bifurcation a large collet ont ete inclus dans ces 3 etudes. Les donnees cliniques (evenements indesirables) et anatomiques ont ete analysees de facon independante. Le suivi anatomique comportait une imagerie a 6 mois (WEBCAST et WEBCAST2) et une imagerie a 12 mois (les 3 etudes). Les resultats anatomiques etaient evalues selon une echelle comportant 3 grades : occlusion complete, collet residuel, anevrisme residuel. Resultats La population globale est constituee de 168 patients (112 femmes, 66,7 %) porteurs de 169 anevrismes dont 14 rompus (8,3 %). Les localisations anevrismales etaient les suivantes : artere cerebrale moyenne dans 86/169 anevrismes (50,9 %), artere communicante anterieure dans 36/169 anevrismes (21,3 %), tronc basilaire dans 30/169 anevrismes (17,8 %) et artere carotide interne (terminaison) dans 17/169 anevrismes (10,1 %). Le placement du WEB a ete possible dans 163/169 anevrismes (96,4 %). La morbidite et la mortalite a 1 mois se sont respectivement elevees a 2,4 % (4/168 patients) et 0,0 % (0/168 patients). Les resultats anatomiques a 12 mois (149 patients) ont montre une occlusion complete dans 82/150 anevrismes (54,7 %), un collet residuel dans 39/150 anevrismes (26,0 %) et un anevrisme residuel dans 29/150 anevrismes (19,3 %). Une occlusion adequate a donc ete obtenue dans 121/150 anevrismes (80,7 %) Conclusion L’analyse dans cette large serie de patients montre une excellente securite du dispositif WEB associee a une grande efficacite a moyen terme.

OBJECTIVE The term classical pituitary apoplexy describes a clinical syndrome characterized by sudden headache, vomiting, visual impairment and meningismus caused by the rapid enlargement of a pituitary adenoma usually due to haemorrhagic infarction of the tumour. Most published reports looking at the clinical features and management of pituitary apoplexy have not differentiated between patients with clinical and subclinical apoplexy, the latter diagnosed at surgery. Furthermore, little is reported on the clinical outcome, in particular visual and endocrinological, and the role of radiotherapy. The purpose of this study was to observe not only the clinical presentation but also the possible predisposing events, investigations, management, clinical outcome as well as the role of radiotherapy in patients presenting with classical pituitary apoplexy. PATIENTS AND DESIGN In a retrospective analysis 1985–96, the medical records of 21 male and 14 female patients (mean age 49.8 years, range 30–74) with classical pituitary apoplexy were reviewed. This represents all patients seen with this condition over the stated period. MEASUREMENTS In all patients, pre- and post- operative measurements were made of FT4, FT3, TSH, PRL, LH, FSH, cortisol (0900 h), GH, oestradiol (females) and testosterone (males). Pituitary imaging was by computerized tomography (CT) scan, magnetic resonance imaging (MRI) or both. RESULTS Patients were followed for up to 11 years (mean 6.3 years: range 0.5–11). Headache (97%) was the commonest presenting symptom, followed by nausea (80%) and a reduction of visual fields (71%). Hypertension, defined as a systolic > 160 mmHg and/or a diastolic > 90 mmHg, was seen in 26% of patients. MRI correctly identified pituitary haemorrhage in 88% (n = 7), but CT scanning identified haemorrhage in only 21% (n = 6). By immunostaining criteria, null-cell adenomas were the most common tumour type (61%). Transsphenoidal surgery resulted in improvement in visual acuity in 86%. Complete restoration of visual acuity occurred in all patients operated on within 8 days but only in 46% of patients operated on after this time (9–34 days). Long-term steroid or thyroid hormone replacement was necessary in 58% and 45% of patients, respectively. Of the male patients, 43% required testosterone replacement, and long-term desmopressin therapy was required in 6%. Only two patients (6%) with tumour recurrence after transsphenoidal surgery for the initial apoplectic event, subsequently required radiotherapy. CONCLUSIONS In classical pituitary apoplexy, headache is the commonest presenting symptom and hypertension may be an important predisposing factor. MRI is the imaging method of choice. Transsphenoidal surgery is safe and effective. It is indicated if there are associated abnormalities of visual acuity or visual fields because, when performed within 8 days, it resulted in significantly greater improvement in visual acuity and fields than if surgery was performed after this time. Radiotherapy is not indicated immediately as the risk of tumour recurrence is small, but careful follow-up initially with annual imaging is indicated in this group.