The Sutureless Excimer Laser Anastomosis Clip Pilot Study: a feasibility and safety study.

BACKGROUND: The excimer laser-assisted non-occlusive anastomosis (ELANA) bypass technique may have the advantage of its non-occlusive design in the treatment of last-resort cases where endovascular treatment or direct clipping is considered to be unsafe. However, the technique remains technically challenging. Therefore, a sutureless ELANA Clip device (SEcl) was developed to simplify the technique avoiding tedious anastomosis stitching in depth. The present study investigates the clinical feasibility and safety of the SEcl technique. METHODS: Three patients with complex and large aneurysms in the anterior circulation were selected after multidisciplinary consensus that the aneurysms were too complex for endovascular or direct clipping treatment options. Bypass surgery was considered as a last-resort treatment option, and after preoperative evaluation and informed consent, SEcl bypass surgery was performed. Applicability, technical aspects and patient outcomes are assessed. RESULTS: All aneurysms were excluded from the circulation. The creation of the intracranial anastomosis was easier and faster. No device-related serious adverse events were encountered, and all outcomes were favorable (one patient stable Modified Rankin Scale, two patients improved). CONCLUSION: The SEcl anastomosis technique is feasible and, considering the severity of the disease, relatively safe. It can be considered a treatment option in very difficult-to treat last-resort aneurysm cases. From this study, further developments in minimizing clip size and application in cardiac surgery are initiated.

RNA-Sequencing Highlights Inflammation and Impaired Integrity of the Vascular Wall in Brain Arteriovenous Malformations.

Background and Purpose- Interventional treatment of unruptured brain arteriovenous malformations (BAVMs) has become increasingly controversial. Because medical therapy is still lacking, we aimed to obtain insight into the disease mechanisms implicated in BAVMs and to identify potential targets for medical treatment to prevent rupture of a BAVM. Methods- We used next-generation RNA sequencing to identify differential expression on a transcriptome-wide level comparing tissue samples of 12 BAVMs to 16 intracranial control arteries. We identified differentially expressed genes by negative binominal generalized log-linear regression (false discovery rate corrected P<0.05). We selected 10 genes for validation using droplet digital polymerase chain reaction. We performed functional pathway analysis accounting for potential gene-length bias, to establish enhancement of biological pathways involved in BAVMs. We further assessed which Gene Ontology terms were enriched. Results- We found 736 upregulated genes in BAVMs including genes implicated in the cytoskeletal machinery and cell-migration and genes encoding for inflammatory cytokines and secretory products of neutrophils and macrophages. Furthermore, we found 498 genes downregulated including genes implicated in extracellular matrix composition, the binary angiopoietin-TIE system, and TGF (transforming growth factor)-ß signaling. We confirmed the differential expression of top 10 ranked genes. Functional pathway analysis showed enrichment of the protein digestion and absorption pathway (false discovery rate-adjusted P=1.70×10-2). We identified 47 enriched Gene Ontology terms (false discovery rate-adjusted P<0.05) implicated in cytoskeleton network, cell-migration, endoplasmic reticulum, transmembrane transport, and extracellular matrix composition. Conclusions- Our genome-wide RNA-sequencing study points to involvement of inflammatory mediators, loss of cerebrovascular quiescence, and impaired integrity of the vascular wall in the pathophysiology of BAVMs. Our study may lend support to potential receptivity of BAVMs to medical therapeutics, including those promoting vessel maturation, and anti-inflammatory and immune-modifying drugs.

Effects of dobutamine and phenylephrine on cerebral perfusion in patients undergoing cerebral bypass surgery: a randomised crossover trial.

BACKGROUND: Patients undergoing cerebral bypass surgery are prone to cerebral hypoperfusion. Currently, arterial blood pressure is often increased with vasopressors to prevent cerebral ischaemia. However, this might cause vasoconstriction of the graft and cerebral vasculature and decrease perfusion. We hypothesised that cardiac output, rather than arterial blood pressure, is essential for adequate perfusion and aimed to determine whether dobutamine administration resulted in greater graft perfusion than phenylephrine administration. METHODS: This randomised crossover study included 10 adult patients undergoing cerebral bypass surgery. Intraoperatively, patients randomly and sequentially received dobutamine to increase cardiac index or phenylephrine to increase mean arterial pressure (MAP). An increase of >10% in cardiac index or >10% in MAP was targeted, respectively. Before both interventions, a reference phase was implemented. The primary outcome was the absolute difference in graft flow between the reference and intervention phase. We compared the absolute flow difference between each intervention and constructed a random-effect linear regression model to explore treatment and carry-over effects. RESULTS: Graft flow increased with a median of 4.1 (inter-quartile range [IQR], 1.7-12.0] ml min-1) after dobutamine administration and 3.6 [IQR, 1.3-7.8] ml min-1 after phenylephrine administration (difference -0.6 ml min-1; 95% confidence interval [CI], -14.5 to 5.3; P=0.441). There was no treatment effect (0.9 ml min-1; 95% CI, 0.0-20.1; P=0.944) and no carry-over effect. CONCLUSIONS: Both dobutamine and phenylephrine increased graft flow during cerebral bypass surgery, without a preference for one method over the other. CLINICAL TRIAL REGISTRATION: Netherlands Trial Register, NL7077 (https://www.trialregister.nl/trial/7077).

Functional and educational outcomes after treatment for intracranial arteriovenous malformations in children.

BACKGROUND: Arteriovenous malformations (AVMs) in the pediatric population are rare, yet they form the most frequent cause of hemorrhagic stroke in children. Compared to adults, children have been suggested to have beneficial neurological outcomes. However, few studies have focused on other variables than neurological outcomes. This study aims to assess the long-term functional and educational outcomes of children after multimodality approach of treatment for intracranial AVMs. METHODS: All children treated in our center between 1998 and 2016 for intracranial AVMs were reviewed. Patient characteristics, as well as AVM specifics, were collected. Functional outcomes were compared using the modified Rankin scale (mRs). Educational levels, using the International Standard Classification of Education (ISCED), were compared to the age-matched general population of the Netherlands. RESULTS: In total, 25 children were included at mean age of 10 years (range 2-16 years). Nineteen patients (76%) presented with intracranial bleeding. Mean follow-up was 11.5 ± 5.3 years (range 4.1-24.4). Four (16%) of patients were treated with embolization, three (12%) with microsurgery, and 18 patients (72%) received a combination of different treatment modalities. Altogether, 21 (84%) were embolized, 14 (56%) were treated with microsurgery, and eight (32%) received stereotactic radiosurgery. One child had a worse mRs at discharge compared to admission; all others improved (n = 11) or were stable (n = 13). At follow-up, all patients scored a stable or improved mRs compared to discharge, with 23 children (92%) scoring mRs 0 or 1. These 23 children followed regular education during follow-up without specialized or adapted schooling. No significant differences in educational level with the age-matched general population were found. CONCLUSION: This retrospective review shows positive long-term results of both functional and educational outcomes after multidisciplinary treatment of pediatric brain AVMs.

RNA Sequencing Analysis of Intracranial Aneurysm Walls Reveals Involvement of Lysosomes and Immunoglobulins in Rupture.

BACKGROUND AND PURPOSE: Analyzing genes involved in development and rupture of intracranial aneurysms can enhance knowledge about the pathogenesis of aneurysms, and identify new treatment strategies. We compared gene expression between ruptured and unruptured aneurysms and control intracranial arteries. METHODS: We determined expression levels with RNA sequencing. Applying a multivariate negative binomial model, we identified genes that were differentially expressed between 44 aneurysms and 16 control arteries, and between 22 ruptured and 21 unruptured aneurysms. The differential expression of 8 relevant and highly significant genes was validated using digital polymerase chain reaction. Pathway analysis was used to identify enriched pathways. We also analyzed genes with an extreme pattern of differential expression: only expressed in 1 condition without any expression in the other. RESULTS: We found 229 differentially expressed genes in aneurysms versus controls and 1489 in ruptured versus unruptured aneurysms. The differential expression of all 8 genes selected for digital polymerase chain reaction validation was confirmed. Extracellular matrix pathways were enriched in aneurysms versus controls, whereas pathways involved in immune response and the lysosome pathway were enriched in ruptured versus unruptured aneurysms. Immunoglobulin genes were expressed in aneurysms, but showed no expression in controls. CONCLUSIONS: For rupture of intracranial aneurysms, we identified the lysosome pathway as a new pathway and found further evidence for the role of the immune response. Our results also point toward a role for immunoglobulins in the pathogenesis of aneurysms. Immune-modifying drugs are, therefore, interesting candidate treatment strategies in the prevention of aneurysm development and rupture.

Research Progresses in Understanding the Pathophysiology of Moyamoya Disease.

BACKGROUND: The pathogenesis of moyamoya disease (MMD) is still unknown. The detection of inflammatory molecules such as cytokines, chemokines and growth factors in MMD patients' biological fluids supports the hypothesis that an abnormal angiogenesis is implicated in MMD pathogenesis. However, it is unclear whether these anomalies are the consequences of the disease or rather causal factors as well as these mechanisms remain insufficient to explain the pathophysiology of MMD. The presence of a family history in about 9-15% of Asian patients, the highly variable incidence rate between different ethnic and sex groups and the age of onset support the role of genetic factors in MMD pathogenesis. However, although some genetic loci have been associated with MMD, few of them have been replicated in independent series. Recently, RNF213 gene was shown to be strongly associated with MMD occurrence with a founder effect in East Asian patients. However, the mechanisms leading from RNF213 mutations to MMD clinical features are still unknown. SUMMARY: The research on pathogenic mechanism of MMD is in its infancy. MMD is probably a complex and heterogeneous disorder, including different phenotypes and genotypes, in which more than a single factor is implicated. KEY MESSAGE: Since the diagnosis of MMD is rapidly increasing worldwide, the development of more efficient stratifying risk systems, including both clinical but also biological drivers became imperative to improve our ability of predict prognosis and to develop mechanism-tailored interventions.

Vessel wall perforation mechanism of the excimer laser-assisted non-occlusive anastomosis technique.

The excimer laser assisted non-occlusive anastomosis (ELANA) technique is used to make anastomoses on intracerebral arteries. This end-to-side anastomosis is created without temporary occlusion of the recipient artery using a 308-nm excimer laser with a ring-shaped multi-fiber catheter to punch an opening in the arterial wall. Over 500 patients have received an ELANA bypass. However, the vessel wall perforation mechanism of the laser catheter is not known exactly and not 100 % successful. In this study, we aimed to understand the mechanism of ELANA vessel perforation using specialized imaging techniques to ultimately improve its effectiveness. High-speed imaging, high-contrast imaging, and high-sensitivity thermal imaging were used to study the laser wall perforation mechanism and reveal the mechanical and thermal effects involved. In vitro, rabbit arteries were exposed with the special designed laser catheter in a setup representative for the clinical setting, in which blood was replaced with a transparent UV absorbing liquid for visualization. We observed that laser vessel wall perforation was caused by explosive vapor bubbles tearing through the vessel wall, mostly within the first 20 of the total 200 pulses. Thermal effects were minimal. Unsymmetrical tension in the vessel wall inducing migration of the flap during laser exposure was observed in case of unsuccessful wall perforations. The laser wall perforation mechanism in the ELANA technique is primarily mechanical. Symmetric tension in the recipient vessel wall is essential and should be trained by neurosurgeons.

Novel Application of Postmortem CT Angiography for Evaluation of the Intracranial Vascular Anatomy in Cadaver Heads.

OBJECTIVE: Postmortem CT angiography is a common procedure used to visualize the entire human vasculature. For visualization of a specific organ's vascular anatomy, casting is the preferred method. Because of the permanent and damaging nature of casting, the organ cannot be further used as an experimental model after angiography. Therefore, there is a need for a minimally traumatic method to visualize organ-specific vascular anatomy. The purpose of this study was to develop and evaluate a contrast enhancement technique that is capable of visualizing the intracranial vascular anatomy while preserving the anatomic integrity in cadaver heads. MATERIALS AND METHODS: Seven human heads were used in this study. Heads were prepared by cannulating the vertebral and internal carotid arteries. Contrast agent was injected as a mixture of tap water, polyethylene glycol 600, and an iodinated contrast agent. Postmortem imaging was executed on a 64-MDCT scanner. Primary image review and 3D reconstruction were performed on a CT workstation. RESULTS: Clear visualization of the major cerebral arteries and smaller intracranial branches was achieved. Adequate visualization was obtained for both the anterior and posterior intracranial circulation. The minimally traumatic angiography method preserved the vascular integrity of the cadaver heads. CONCLUSION: A novel application of postmortem CT angiography is presented here. The technique can be used for radiologic evaluation of the intracranial circulation in cadaver heads. After CT angiography, the specimen can be used for further experimental or laboratory testing and teaching purposes.

"STA-MCA bypass with encephalo-duro-myo-synangiosis combined with bifrontal encephalo-duro-periosteal-synangiosis" as a one-staged revascularization strategy for pediatric moyamoya vasculopathy.

PURPOSE: Moyamoya vasculopathy progressively compromises cerebral blood flow resulting in chronic hypoperfusion. The middle cerebral artery (MCA) territory and the bifrontal areas are the regions most frequently affected. Although most techniques aim to only revascularize the MCA territory, augmentation of blood flow of the bifrontal areas is of importance in the pediatric moyamoya population since these regions play an important role in cognition, intellectual development, and in lower extremity and sphincter function. We recently described a one-staged surgical procedure combining revascularization of three regions, the MCA territory unilaterally and the frontal areas bilaterally. The purpose of this article is to report our surgical experience in eight children and to emphasize the rational for bifrontal revascularization. METHODS: We report a case series consisting of eight children where the following surgical strategy was applied: (1) a direct superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass with encephalo-duro-myo-synangiosis (EDMS) for unilateral MCA revascularization; in combination with (2) a bifrontal encephalo-duro-periosteal-synangiosis (EDPS) for bifrontal revascularization. Patients' characteristics and 30-day follow-up data are reported. RESULTS: The patient group consisted of six girls and two boys (mean age 10.0, range 4.2-17.5 years): six children presented with moyamoya disease, two with moyamoya syndrome. We performed a one-staged revascularization of one MCA territory and both frontal areas in all patients. No significant complications occurred. Two patients experienced postoperative focal seizures, successfully treated with anti-epileptic medication. CONCLUSIONS: The single-staged STA-MCA bypass with EDMS combined with bifrontal EDPS allowed revascularization of three regions (the MCA territory unilaterally and the frontal areas bilaterally) and may serve as an alternative and safe treatment option for pediatric moyamoya patients.

Comparing five simple vascular storage protocols.

BACKGROUND: We aim to find a storage protocol for vessels that preserves their dimensional, histologic, and mechanical characteristics to facilitate reproducible anastomosis experiments and microsurgical training with constant quality. MATERIALS AND METHODS: We compared stored rabbit aortas, harvested in a slaughterhouse, using five different protocols with fresh controls. Aortas were preserved for 125 d in (1) NaCl 0.9% at -18°C, (2) Roswell Park Memorial Institute 1640 90% with 10% dimethyl sulfoxide (RPMI/DMSO) at -18°C, (3) RPMI/DMSO at -70°C, (4) glycerol 85% at 4°C, and (5) glycerol in stepwise increased concentrations until 85% at 4°C. After preservation, we measured vessel diameter, wall thickness, and Young's Modulus indicating stiffness. Neurosurgeons compared stored vessels with fresh vessels, blinded for preservation subgroup. We performed histologic assessment blinded for preservation subgroup. RESULTS: Fresh rabbit aortas showed a mean diameter of 2.65 ± 0.14 mm, a mean wall thickness of 126 ± 22 µm, and a Young's Modulus of 11.4 ± 2.4 N/mm(2). NaCl 0.9%-preserved aortas showed a significantly increased vessel diameter and decreased stiffness. RPMI/DMSO-preserved aortas showed no significant differences from fresh aortas in dimensions and mechanical characteristics. Glycerol-preserved tissue showed a significant increase in wall thickness, a related significant decrease in diameter, and increase in stiffness. Neurosurgeons regarded RPMI/DMSO tissue as most comparable with fresh tissue. Histologic assessment revealed no differences between the different protocols and fresh control group. CONCLUSIONS: Storage of rabbit aortas in RPMI/DMSO most adequately preserves their dimensional and mechanical properties.

Transcranial Doppler ultrasonography CO2 reactivity does not predict recurrent ischaemic stroke in patients with symptomatic carotid artery occlusion.

BACKGROUND: Patients with transient ischaemic attacks (TIAs) or minor disabling ischaemic stroke associated with an internal carotid artery (ICA) occlusion have a high risk of recurrent stroke in case of compromised cerebral blood flow. Recent studies showed that increased oxygen extraction fraction measured by positron emission tomography (PET) is still an independent predictor of subsequent stroke under current medical treatment, but PET facilities are not widely available. Transcranial Doppler (TCD) ultrasonography CO2 reactivity is a cheap and non-invasive alternative to measure haemodynamic compromise. The aim of our study was to investigate whether TCD CO2 reactivity is an independent predictor of recurrent ischaemic stroke in a large cohort of patients with symptomatic ICA occlusion in a time where rigorous control of vascular risk factors has been widely implemented in clinical practice. METHODS: Between July 1995 and December 2009, we included consecutive patients with TIAs or minor disabling ischaemic stroke (modified Rankin Scale ≤3) associated with ICA occlusion who were referred to the University Medical Centre Utrecht, The Netherlands. All patients were treated with antiplatelet therapy and received rigorous control of vascular risk factors, including statins, treatment for diabetes and hypertension and lifestyle advices. CO2 reactivity was measured with TCD within 3 months after presentation. We determined the predictive value of TCD CO2 reactivity for recurrent ischaemic stroke using Cox proportional hazard analysis. RESULTS: We included 201 patients with a median follow-up time of 7.1 years. Mean CO2 reactivity was 15% (±20 standard deviation). The annual rate for ipsilateral ischaemic stroke was 2.2% [95% confidence interval (CI) 1.4-3.2] and for any recurrent stroke 3.2% (95% CI 2.3-4.4). We did not find a significant relationship between CO2 reactivity and the risk of ipsilateral [hazard ratio (HR) for every increase in percentage point 1.01, 95% CI 0.99-1.02] or any recurrent ischaemic stroke (HR 1.01, 95% CI 0.998-1.02). Multivariable analysis showed a significant relationship with history of stroke (HR 4.0, 95% CI 1.8-9.0) for ipsilateral recurrent stroke, and age (HR for increase per year 1.05, 95% CI 1.01-1.09) and a history of stroke (HR 3.4, 95% CI 1.7-6.6) for any recurrent stroke. CONCLUSIONS: In patients with TIAs or non-disabling stroke associated with occlusion of the carotid artery, the long-term annual risk of stroke is generally low with careful control of vascular risk factors. Impaired CO2 reactivity measured within 3 months after presentation does not identify the subgroup of patients at high risk of recurrent ischaemic stroke.

Recent advances in moyamoya disease: pathophysiology and treatment.

Moyamoya disease is a progressive intracranial arteriopathy characterized by bilateral stenosis of the distal portion of the internal carotid artery and the proximal anterior and middle cerebral arteries, resulting in transient ischemic attacks or strokes. The pathogenesis of moyamoya disease remains unresolved, but recent advances have suggested exciting new insights into a genetic contribution as well as into other pathophysiological mechanisms. Treatment that may halt progression of the disease or even reverse the intracranial arteriopathy is yet to be found. There are strong indications that neurosurgical intervention, through direct, indirect, or combined revascularization surgery, can reduce the risk of ischemic stroke and possibly also cognitive dysfunction by improving cerebral perfusion, although randomized clinical trials have not been performed. Many questions regarding the indication for and timing of surgery remain unanswered. In this review, we discuss recent developments in the pathogenesis and treatment of moyamoya disease.

"How I Do It:" Non-occlusive High Flow Bypass Surgery.

Giant intracranial aneurysms are a formidable challenge for treatment, considering their grim prognosis. Until lately, endovascular treatment options have been disappointing, and neurosurgical treatment results are by far the most promising. In the neurosurgical treatment of giant intracranial aneurysms, the non-occlusive nature of the ELANA anastomosis technique is a major advantage in flow replacement bypass surgery where large proximal arteries with higher flows need to be replaced or reconstructed. The construction of a deep intracranial anastomosis using the ELANA technique needs less vessel exposure than when using a conventional occlusive technique. This extra advantage facilitates the construction of anastomoses even on the ICA, MCA, ACA, P1, P2, SCA or BA, using the trans-Sylvian route only, without major skull base surgery. Several different types of EC-IC and IC-IC flow replacement bypass are now safely applicable due to the non-occlusive character of this technique.Future improvements of the technique are focused on sutureless applications, graft improvements and Flow Model Simulation. It is clear that not only conventional bypass techniques, but also, and even especially, the ELANA bypass technique, are of great value in the treatment of giant aneurysms.

MRI in patients with a cerebral aneurysm clip; review of the literature and incident databases and recommendations for the Netherlands.

BACKGROUND: In the past ferromagnetic cerebral aneurysm clips that are contraindicated for Magnetic Resonance Imaging (MRI) have been implanted. However, the specific clip model is often unknown for older clips, which poses a problem for individual patient management in clinical care. METHODS: Literature and incident databases were searched, and a survey was performed in the Netherlands that identified time periods at which ferromagnetic and non-ferromagnetic clip models were implanted. Considering this information in combination with a national expert opinion, we describe an approach for risk assessment prior to MRI examinations in patients with aneurysm clips. The manuscript is limited to MRI at 1.5 T or 3 T whole body MRI systems with a horizontal closed bore superconducting magnet, covering the majority of clinical Magnetic Resonance (MR) systems. RESULTS: From the literature a list of ferromagnetic clip models was obtained. The risk of movement or rotation of the clip due to the main magnetic field in case of a ferromagnetic clip is the main concern. In the incident databases records of four serious incidents due to aneurysm clips in MRI were found. The survey in the Netherlands showed that from 2000 onwards, no ferromagnetic clips were implanted in Dutch hospitals. DISCUSSION: Recommendations are provided to help the MR safety expert assessing the risks when a patient with a cerebral aneurysm clip is referred for MRI, both for known and unknown clip models. This work was part of the development of a guideline by the Dutch Association of Medical Specialists.

Anesthesia Depresses Cerebrovascular Reactivity to Acetazolamide in Pediatric Moyamoya Vasculopathy.

Measurements of cerebrovascular reactivity (CVR) are essential for treatment decisions in moyamoya vasculopathy (MMV). Since MMV patients are often young or cognitively impaired, anesthesia is commonly used to limit motion artifacts. Our aim was to investigate the effect of anesthesia on the CVR in pediatric MMV. We compared the CVR with multidelay-ASL and BOLD MRI, using acetazolamide as a vascular stimulus, in all awake and anesthesia pediatric MMV scans at our institution. Since a heterogeneity in disease and treatment influences the CVR, we focused on the (unaffected) cerebellum. Ten awake and nine anesthetized patients were included. The post-acetazolamide CBF and ASL-CVR were significantly lower in anesthesia patients (47.1 ± 15.4 vs. 61.4 ± 12.1, p = 0.04; 12.3 ± 8.4 vs. 23.7 ± 12.2 mL/100 g/min, p = 0.03, respectively). The final BOLD-CVR increase (0.39 ± 0.58 vs. 3.6 ± 1.2% BOLD-change (mean/SD), p < 0.0001), maximum slope of increase (0.0050 ± 0.0040%/s vs. 0.017 ± 0.0059%, p < 0.0001), and time to maximum BOLD-increase (~463 ± 136 and ~697 ± 144 s, p = 0.0028) were all significantly lower in the anesthesia group. We conclude that the response to acetazolamide is distinctively different between awake and anesthetized MMV patients, and we hypothesize that these findings can also apply to other diseases and methods of measuring CVR under anesthesia. Considering that treatment decisions heavily depend on CVR status, caution is warranted when assessing CVR under anesthesia.

The profile of cognitive impairment and hemodynamic compromise in moyamoya: a single-center prospective cohort study.

OBJECTIVE: Patients with moyamoya vasculopathy often experience cognitive impairments. In this prospective single-center study, the authors investigated the profile of neurocognitive impairment and its relation with the severity of ischemic brain lesions and hemodynamic compromise. METHODS: Patients treated in a Dutch tertiary referral center were prospectively included. All patients underwent standardized neuropsychological evaluation, MRI, digital subtraction angiography, and [15O]H2O-PET (to measure cerebrovascular reactivity [CVR]). The authors determined z-scores for 7 cognitive domains and the proportion of patients with cognitive impairment (z-score < -1.5 SD in at least one domain). The authors explored associations between patient characteristics, imaging and CVR findings, and cognitive scores per domain by using multivariable linear regression and Bayesian regression analysis. RESULTS: A total of 40 patients (22 children; 75% females) were included. The median age for children was 9 years (range 1-16 years); for adults it was 39 years (range 19-53 years). Thirty patients (75%) had an infarction, and 31 patients (78%) had impaired CVR (steal phenomenon). Six of 7 cognitive domains scored below the population norm. Twenty-nine patients (73%) had cognitive impairment. Adults performed better than children in the cognitive domain visuospatial functioning (p = 0.033, Bayes factor = 4.0), and children performed better in processing speed (p = 0.041, Bayes factor = 3.5). The authors did not find an association between infarction, white matter disease, or CVR and cognitive domains. CONCLUSIONS: In this Western cohort, cognitive functioning in patients with moyamoya vasculopathy was below the population norm, and 73% had cognitive impairment in at least one domain. The cognitive profile differed between adults and children. The authors could not find an association with imaging findings.

Quality of life outcomes over time in patients with unruptured intracranial aneurysms with and without preventive occlusion: a prospective cohort study.

OBJECTIVE: In counselling patients with an unruptured intracranial aneurysm (UIA), quality-of-life (QoL) outcomes are important for informed decision-making. We evaluated QoL outcomes in patients with and without preventive aneurysm occlusion at multiple time points during the first year after UIA diagnosis and studied predictors of QoL outcomes. METHODS: We performed a prospective cohort study in patients ≥18 years old with a newly diagnosed UIA in two tertiary referral centers in the Netherlands between 2017 and 2019. Patients were sent QoL questionnaires at 7 (aneurysm occlusion) or 5 (no occlusion) moments during the first year after diagnosis. We collected baseline data on patient and aneurysm characteristics, passive coping style (Utrecht Coping List), occlusion modality, and neurological complications. We assessed health-related QoL (HRQoL) with the EuroQol 5-dimensions (EQ-5D), emotional functioning with the Hospital Anxiety and Depression Scale (HADS), and restrictions in daily activities with the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P). We used a linear mixed effects model to assess the course of QoL over time and to explore predictors of QoL outcomes. RESULTS: Of 153 eligible patients, 99 (65%) participated, of whom 30/99 (30%) underwent preventive occlusion. Patients undergoing occlusion reported higher baseline levels of passive coping, anxiety and depression, and restrictions than patients without occlusion. During recovery after occlusion, patients reported more restrictions compared to baseline (adjusted USER-P decrease one-month post-occlusion: -12.8 (95%CI:-23.8- -1.9). HRQoL and emotional functioning gradually improved after occlusion (EQ-5D increase at one-year: 8.6 (95%CI:0.1-17.0) and HADS decrease at one-year: -5.4 (95%CI:-9.4- -1.5)). In patients without occlusion, the largest HRQoL improvement occurred directly after visiting the outpatient aneurysm clinic (EQ-5D increase: 9.2 (95%CI:5.5-12.8)). At one-year, QoL outcomes were comparable in patients with and without occlusion. Factors associated with worse QoL outcomes were a passive coping style in all patients, complications in patients with occlusion and higher rupture risks in patients without occlusion. CONCLUSIONS: After UIA diagnosis, QoL improves gradually after preventive occlusion and directly after counselling at the outpatient clinic in patients without occlusion, resulting in comparable one-year QoL outcomes. A passive coping style is an important predictor of poor QoL outcomes in all UIA patients.

Clinical Outcome, Cognition, and Cerebrovascular Reactivity after Surgical Treatment for Moyamoya Vasculopathy: A Dutch Prospective, Single-Center Cohort Study.

Background: It remains unclear whether revascularization of moyamoya vasculopathy (MMV) has a positive effect on cognitive function. In this prospective, single-center study, we investigated the effect of revascularization on cognitive function in patients with MMV. We report clinical and radiological outcome parameters and the associations between clinical determinants and change in neurocognitive functioning. Methods: We consecutively included all MMV patients at a Dutch tertiary referral hospital who underwent pre- and postoperative standardized neuropsychological evaluation, [15O]H2O-PET (including cerebrovascular reactivity (CVR)), MRI, cerebral angiography, and completed standardized questionnaires on clinical outcome and quality of life (QOL). To explore the association between patient characteristics, imaging findings, and change in the z-scores of the cognitive domains, we used multivariable linear- and Bayesian regression analysis. Results: We included 40 patients of whom 35 (27 females, 21 children) were treated surgically. One patient died after surgery, and two withdrew from the study. TIA- and headache frequency and modified Rankin scale (mRS) improved (resp. p = 0.001, 0.019, 0.039). Eleven patients (seven children) developed a new infarct during follow-up (31%), five of which were symptomatic. CVR-scores improved significantly (p < 0.0005). The language domain improved (p = 0.029); other domains remained stable. In adults, there was an improvement in QOL. We could not find an association between change in imaging and cognitive scores. Conclusion: In this cohort of Western MMV patients, TIA frequency, headache, CVR, and mRS improved significantly after revascularization. The language domain significantly improved, while others remained stable. We could not find an association between changes in CVR and cognitive scores.

Development of the SAFETEA Scores for Predicting Risks of Complications of Preventive Endovascular or Microneurosurgical Intracranial Aneurysm Occlusion.

OBJECTIVE: Preventive unruptured intracranial aneurysm occlusion can reduce the risk of subarachnoid hemorrhage, but both endovascular and microneurosurgical treatment carry a risk of serious complications. To improve individualized management decisions, we developed risk scores for complications of endovascular and microneurosurgical treatment based on easily retrievable patient, aneurysm, and treatment characteristics. METHODS: For this multicenter cohort study, we combined individual patient data from unruptured intracranial aneurysm patients ≥18 years undergoing preventive endovascular treatment (standard, balloon-assisted or stent-assisted coiling, Woven EndoBridge-device, or flow-diverting stent) or microneurosurgical clipping at one of 10 participating centers from three continents between 2000-2018. The primary outcome was death from any cause or clinical deterioration from neurological complications ≤30 days. We selected predictors based on previous knowledge about relevant risk factors and predictor performance and studied the association between predictors and complications with logistic regression. We assessed model performance with calibration plots and concordance (c) statistics. RESULTS: Of 1282 included patients, 94 (7.3%) had neurological symptoms that resolved <30 days, 140 (10.9%) had persisting neurological symptoms, and 6 died (0.5%)). At 30 days, 52 patients (4.1%) were dead or dependent. Predictors of procedural complications were: size of aneurysm, aneurysm location, familial subarachnoid hemorrhage, earlier atherosclerotic disease, treatment volume, endovascular modality (for endovascular treatment) or extra aneurysm configuration factors (for microneurosurgical treatment; branching artery from aneurysm neck or unfavorable dome-to-neck ratio), and age (acronym: SAFETEA). For endovascular treatment (n=752), the c-statistic was 0.72 (95%CI:0.67-0.77) and the absolute complication risk ranged from 3.2% (95%CI:1.6%-14.9%;≤1 point) to 33.1% (95%CI:25.4%-41.5%;≥6 points). For microneurosurgical treatment (n=530), the c-statistic was 0.72 (95%CI:0.67-0.77) and the complication risk ranged from 4.9% (95%CI:1.5%-14.9%;≤1 point) to 49.9% (95%CI:39.4%-60.6%;≥6 points). CONCLUSIONS: The SAFETEA risk scores for endovascular and microneurosurgical treatment are based on seven easily retrievable risk factors to predict the absolute risk of procedural complications in patients with unruptured intracranial aneurysms. The scores need external validation before the predicted risks can be properly used to support decision making in clinical practice.

Symptomatic internal carotid artery occlusion: a long-term follow-up study.

BACKGROUND: Information on outcome of patients with occlusion of the internal carotid artery (ICA) is limited by the short duration of follow-up and lack of haemodynamic studies on the brain. METHODS: The authors prospectively investigated 117 consecutive patients with transient or moderately disabling cerebral or retinal ischaemia associated with ICA occlusion between September 1995 and July 1998, and followed them until June 2008. The authors determined the risk of recurrent ischaemic stroke and other vascular events and prognostic factors, including collateral pathways and transcranial Doppler CO(2) reactivity. RESULTS: Patients (mean age 61± 9 years; 80% male) were followed for a median time of 10.2 years; 22 patients underwent endarterectomy for contralateral ICA stenosis and 16 extracranial/intracranial bypass surgery. Recurrent ischaemic stroke occurred in 23 patients, resulting in an annual rate of 2.4% (95% CI 1.5 to 3.6). Risk factors for recurrent ischaemic stroke were age (HR 1.07, 1.02 to 1.13), cerebral rather than retinal symptoms (HR 8.0, 1.1 to 60), recurrent symptoms after documented occlusion (HR 4.4, 1.6 to 12), limb-shaking transient ischaemic attacks at presentation (HR 7.5, 2.6 to 22), history of stroke (HR 2.8, 1.2 to 6.7) and leptomeningeal collaterals (HR 5.2, 1.5 to 17) but not CO(2) reactivity (HR 1.01, 0.99 to 1.02). The composite event of any vascular event occurred in 57 patients, resulting in an annual rate of 6.4% (95% CI 4.9 to 8.2). CONCLUSION: The prognosis of patients with transient ischaemic attack or minor stroke and ICA occlusion depends on age, several clinical factors and the presence of leptomeningeal collaterals. The long-term risk of recurrent ischaemic stroke is much lower than that of other vascular events.