Dynamics of broad H3K4me3 domains uncover an epigenetic switch between cell identity and cancer-related genes.

Broad domains of H3K4 methylation have been associated with consistent expression of tissue-specific, cell identity, and tumor suppressor genes. Here, we identified broad domain-associated genes in healthy human thymic T cell populations and a collection of T cell acute lymphoblastic leukemia (T-ALL) primary samples and cell lines. We found that broad domains are highly dynamic throughout T cell differentiation, and their varying breadth allows the distinction between normal and neoplastic cells. Although broad domains preferentially associate with cell identity and tumor suppressor genes in normal thymocytes, they flag key oncogenes in T-ALL samples. Moreover, the expression of broad domain-associated genes, both coding and noncoding, is frequently deregulated in T-ALL. Using two distinct leukemic models, we showed that the ectopic expression of T-ALL oncogenic transcription factor preferentially impacts the expression of broad domain-associated genes in preleukemic cells. Finally, an H3K4me3 demethylase inhibitor differentially targets T-ALL cell lines depending on the extent and number of broad domains. Our results show that the regulation of broad H3K4me3 domains is associated with leukemogenesis, and suggest that the presence of these structures might be used for epigenetic prioritization of cancer-relevant genes, including long noncoding RNAs.

IL-7 receptor expression is frequent in T-cell acute lymphoblastic leukemia and predicts sensitivity to JAK inhibition.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a dismal prognosis related to refractory/relapsing diseases, raising the need for new targeted therapies. Activating mutations of interleukin-7-receptor pathway genes (IL-7Rp) play a proven leukemia-supportive role in T-ALL. JAK inhibitors, such as ruxolitinib, have recently demonstrated preclinical efficacy. However, prediction markers for sensitivity to JAK inhibitors are still lacking. Herein, we show that IL-7R (CD127) expression is more frequent (∼70%) than IL-7Rp mutations in T-ALL (∼30%). We compared the so-called nonexpressers (no IL-7R expression/IL-7Rp mutation), expressers (IL7R expression without IL-7Rp mutation), and mutants (IL-7Rp mutations). Integrative multiomics analysis outlined IL-7R deregulation in virtually all T-ALL subtypes, at the epigenetic level in nonexpressers, genetic level in mutants, and posttranscriptional level in expressers. Ex vivo data using primary-derived xenografts support that IL-7Rp is functional whenever the IL-7R is expressed, regardless of the IL-7Rp mutational status. Consequently, ruxolitinib impaired T-ALL survival in both expressers and mutants. Interestingly, we show that expressers displayed ectopic IL-7R expression and IL-7Rp addiction conferring a deeper sensitivity to ruxolitinib. Conversely, mutants were more sensitive to venetoclax than expressers. Overall, the combination of ruxolitinib and venetoclax resulted in synergistic effects in both groups. We illustrate the clinical relevance of this association by reporting the achievement of complete remission in 2 patients with refractory/relapsed T-ALL. This provides proof of concept for translation of this strategy into clinics as a bridge-to-transplantation therapy. IL7R expression can be used as a biomarker for sensitivity to JAK inhibition, thereby expanding the fraction of patients with T-ALL eligible for ruxolitinib up to nearly ∼70% of T-ALL cases.

Histone Variant H2A.L.2 Guides Transition Protein-Dependent Protamine Assembly in Male Germ Cells.

Histone replacement by transition proteins (TPs) and protamines (Prms) constitutes an essential step for the successful production of functional male gametes, yet nothing is known on the underlying functional interplay between histones, TPs, and Prms. Here, by studying spermatogenesis in the absence of a spermatid-specific histone variant, H2A.L.2, we discover a fundamental mechanism involved in the transformation of nucleosomes into nucleoprotamines. H2A.L.2 is synthesized at the same time as TPs and enables their loading onto the nucleosomes. TPs do not displace histones but rather drive the recruitment and processing of Prms, which are themselves responsible for histone eviction. Altogether, the incorporation of H2A.L.2 initiates and orchestrates a series of successive transitional states that ultimately shift to the fully compacted genome of the mature spermatozoa. Hence, the current view of histone-to-nucleoprotamine transition should be revisited and include an additional step with H2A.L.2 assembly prior to the action of TPs and Prms.

Short tandem repeats are important contributors to silencer elements in T cells.

The action of cis-regulatory elements with either activation or repression functions underpins the precise regulation of gene expression during normal development and cell differentiation. Gene activation by the combined activities of promoters and distal enhancers has been extensively studied in normal and pathological contexts. In sharp contrast, gene repression by cis-acting silencers, defined as genetic elements that negatively regulate gene transcription in a position-independent fashion, is less well understood. Here, we repurpose the STARR-seq approach as a novel high-throughput reporter strategy to quantitatively assess silencer activity in mammals. We assessed silencer activity from DNase hypersensitive I sites in a mouse T cell line. Identified silencers were associated with either repressive or active chromatin marks and enriched for binding motifs of known transcriptional repressors. CRISPR-mediated genomic deletions validated the repressive function of distinct silencers involved in the repression of non-T cell genes and genes regulated during T cell differentiation. Finally, we unravel an association of silencer activity with short tandem repeats, highlighting the role of repetitive elements in silencer activity. Our results provide a general strategy for genome-wide identification and characterization of silencer elements.

Dynamic Competing Histone H4 K5K8 Acetylation and Butyrylation Are Hallmarks of Highly Active Gene Promoters.

Recently discovered histone lysine acylation marks increase the functional diversity of nucleosomes well beyond acetylation. Here, we focus on histone butyrylation in the context of sperm cell differentiation. Specifically, we investigate the butyrylation of histone H4 lysine 5 and 8 at gene promoters where acetylation guides the binding of Brdt, a bromodomain-containing protein, thereby mediating stage-specific gene expression programs and post-meiotic chromatin reorganization. Genome-wide mapping data show that highly active Brdt-bound gene promoters systematically harbor competing histone acetylation and butyrylation marks at H4 K5 and H4 K8. Despite acting as a direct stimulator of transcription, histone butyrylation competes with acetylation, especially at H4 K5, to prevent Brdt binding. Additionally, H4 K5K8 butyrylation also marks retarded histone removal during late spermatogenesis. Hence, alternating H4 acetylation and butyrylation, while sustaining direct gene activation and dynamic bromodomain binding, could impact the final male epigenome features.

Defining the optimal size of an aspiration catheter in relation to the arterial diameter during mechanical thrombectomy for stroke.

BACKGROUND: Mechanical thrombectomy for acute ischemic stroke is effective and includes different technical approaches. Operators use direct aspiration, a stent retriever, or a combination of both. Direct aspiration can be performed with various catheters of different sizes depending on the diameter of the occluded vessel. PURPOSE: We studied the relationship between the catheter diameter in regards to the occluded vessel diameter and the rate of successful recanalization. MATERIALS AND METHODS: We conducted a retrospective, monocentric study on a series of consecutive patients treated with mechanical thrombectomy. For each procedure, we extracted each attempt that used direct aspiration and rated the attempt as successful or unsuccessful. We also measured the occluded artery diameter and calculated the ratio between the occluded artery and the aspiration catheter diameters. We tested the association between the diameter ratio and the recanalization status. We also performed inter-rater agreement for the arterial diameter measurement between three interventional neuroradiologists. RESULTS: We included 119 patients with 201 attempts of direct aspiration. A higher diameter ratio was associated with a higher recanalization rate. The analysis in terciles showed that the odds of success were 4.80 higher when the ratio was >0.71 vs <0.54 (p < 0.01). Inter-rater agreement showed near-perfect intraclass correlation with 0.93 (0.91-0.94) consistency and 0.92 (0.90-0.94) absolute agreement. CONCLUSIONS: We demonstrated an association between higher recanalization and a diameter of ratio >0.71 between the aspiration catheter and the occluded artery. These results could guide intraoperative decisions regarding the appropriate selection of aspiration catheters during mechanical thrombectomy increasing the rate of successful recanalisation. A larger study could provide additional data to further specify the optimal ratio.

PRC2 loss of function confers a targetable vulnerability to BET proteins in T-ALL.

T-cell acute lymphoblastic leukemia (T-ALL) is a group of aggressive hematological cancers with dismal outcomes that are in need of new therapeutic options. Polycomb repressor complex 2 (PRC2) loss-of-function alterations were reported in pediatric T-ALL, yet their clinical relevance and functional consequences remain elusive. Here, we extensively analyzed PRC2 alterations in a large series of 218 adult T-ALL patients. We found that PRC2 genetic lesions are frequent events in T-ALL and are not restricted to early thymic precursor ALL. PRC2 loss of function associates with activating mutations of the IL7R/JAK/STAT pathway. PRC2-altered T-ALL patients respond poorly to prednisone and have low bone marrow blast clearance and persistent minimal residual disease. Furthermore, we identified that PRC2 loss of function profoundly reshapes the genetic and epigenetic landscapes, leading to the reactivation of stem cell programs that cooperate with bromodomain and extraterminal (BET) proteins to sustain T-ALL. This study identifies BET proteins as key mediators of the PRC2 loss of function-induced remodeling. Our data have uncovered a targetable vulnerability to BET inhibition that can be exploited to treat PRC2-altered T-ALL patients.

Transcriptomic Studies of Antidepressant Action in Rodent Models of Depression: A First Meta-Analysis.

Antidepressants (ADs) are, for now, the best everyday treatment we have for moderate to severe major depressive episodes (MDEs). ADs are among the most prescribed drugs in the Western Hemisphere; however, the trial-and-error prescription strategy and side-effects leave a lot to be desired. More than 60% of patients suffering from major depression fail to respond to the first AD they are prescribed. For those who respond, full response is only observed after several weeks of treatment. In addition, there are no biomarkers that could help with therapeutic decisions; meanwhile, this is already true in cancer and other fields of medicine. For years, many investigators have been working to decipher the underlying mechanisms of AD response. Here, we provide the first systematic review of animal models. We thoroughly searched all the studies involving rodents, profiling transcriptomic alterations consecutive to AD treatment in naïve animals or in animals subjected to stress-induced models of depression. We have been confronted by an important heterogeneity regarding the drugs and the experimental settings. Thus, we perform a meta-analysis of the AD signature of fluoxetine (FLX) in the hippocampus, the most studied target. Among genes and pathways consistently modulated across species, we identify both old players of AD action and novel transcriptional biomarker candidates that warrant further investigation. We discuss the most prominent transcripts (immediate early genes and activity-dependent synaptic plasticity pathways). We also stress the need for systematic studies of AD action in animal models that span across sex, peripheral and central tissues, and pharmacological classes.

Mechanical Thrombectomy for Acute Ischemic Stroke Amid the COVID-19 Outbreak: Decreased Activity, and Increased Care Delays.

BACKGROUND AND PURPOSE: The efficiency of prehospital care chain response and the adequacy of hospital resources are challenged amid the coronavirus disease 2019 (COVID-19) outbreak, with suspected consequences for patients with ischemic stroke eligible for mechanical thrombectomy (MT). METHODS: We conducted a prospective national-level data collection of patients treated with MT, ranging 45 days across epidemic containment measures instatement, and of patients treated during the same calendar period in 2019. The primary end point was the variation of patients receiving MT during the epidemic period. Secondary end points included care delays between onset, imaging, and groin puncture. To analyze the primary end point, we used a Poisson regression model. We then analyzed the correlation between the number of MTs and the number of COVID-19 cases hospitalizations, using the Pearson correlation coefficient (compared with the null value). RESULTS: A total of 1513 patients were included at 32 centers, in all French administrative regions. There was a 21% significant decrease (0.79; [95%CI, 0.76-0.82]; P<0.001) in MT case volumes during the epidemic period, and a significant increase in delays between imaging and groin puncture, overall (mean 144.9±SD 86.8 minutes versus 126.2±70.9; P<0.001 in 2019) and in transferred patients (mean 182.6±SD 82.0 minutes versus 153.25±67; P<0.001). After the instatement of strict epidemic mitigation measures, there was a significant negative correlation between the number of hospitalizations for COVID and the number of MT cases (R2 -0.51; P=0.04). Patients treated during the COVID outbreak were less likely to receive intravenous thrombolysis and to have unwitnessed strokes (both P<0.05). CONCLUSIONS: Our study showed a significant decrease in patients treated with MTs during the first stages of the COVID epidemic in France and alarming indicators of lengthened care delays. These findings prompt immediate consideration of local and regional stroke networks preparedness in the varying contexts of COVID-19 pandemic evolution.

Quantitative evaluation of WEB shape modification: A five-year follow-up study.

BACKGROUND AND PURPOSE: Web shape modification (WSM) has previously been associated with aneurysm recurrence. We report here our five-year experience of WEB device use with a quantitative approach of the WSM phenomenon. METHODS: From July 2012 to July 2017, 50 patients with 51 unruptured aneurysms treated with the WEB device have been prospectively enrolled in our data base and retrospectively analyzed. An independent "core lab" evaluated anatomical results and potential WSM in DSA follow-up. We defined the WSM ratio (WSMr) as a relative index between the height and the width of the device in working projections which gave an evaluation of the device deformation over the time. RESULTS: During the total follow-up period, WSM was observed in 35/48 aneurysms (72.9%). Adequate occlusion rates were 87.0% and 92.6% with and without WSM respectively (P = 0.65). 30 out the 35 (85.7%) shape modifications were already noticed at short-term follow-up (6-month DSA). 33 patients had 2 DSA controls and WSMr measurements were available in 24 patients: 18 (75%) with WSM and 6 (25%) without WSM. In the group with WSM, WSMr values were 0.80 in post-embolization, 0.52 at the first DSA angiogram and 0.42 at the second DSA angiogram. CONCLUSION: WEB shape modification was observed in more than half of cases but with no influence regarding adequate occlusion rate. This quantitative approach of WSM highlights that this phenomenon appears to be early and progressive over time. This supports the hypothesis that WSM could be more probably related to aneurysm healing rather than external compression.

Perspectives on Remote Robotic-Assisted Stroke Treatment: A Commentary Paper.

The proved feasibility of robotic-assisted endovascular treatment of intracranial aneurysms has stimulated the idea of a potential application of remote robotics for the treatment of acute ischemic stroke. The possibility of developing a more advanced remote-controlled robotic system capable of performing a complete mechanical thrombectomy procedure would help bridge the health care gap of lack of technical expertise in isolated areas. This possibility could allow a more equitable access to mechanical thrombectomy to a larger number of patients and be a breakthrough for acute ischemic stroke care worldwide. Many aspects around the technical, human, financial, and regulatory requirements should be discussed to implement remote robotic-assisted procedures. In this State of Practice article, we aimed to outline the major challenges that must be considered, as well as proposed solutions. However, different solutions may be applied in different health care systems on the basis of the availability of human and financial resources.

Telestroke network to robotic telestroke network: How to upgrade regional stroke care to include remote robotics?

Objective: Selected patients with large vessel occlusion (LVO) strokes can benefit from endovascular therapy (EVT). However, the effectiveness of EVT is largely dependent on how quickly the patient receives treatment. Recent technological developments have led to the first neurointerventional treatments using robotic assistance, opening up the possibility of performing remote stroke interventions. Existing telestroke networks provide acute stroke care, including remote administration of intravenous thrombolysis (IVT). Therefore, the introduction of remote EVT in distant stroke centers requires an adaptation of the existing telestroke networks. The aim of this work was to propose a framework for centers that are potential candidates for telerobotics according to the resources currently available in these centers. Methods: In this paper, we highlight the future challenges for including remote robotics in telestroke networks. A literature review provides potential solutions. Results: Existing telestroke networks need to determine which centers to prioritize for remote robotic technologies based on objective criteria and cost-effectiveness analysis. Organizational challenges include regional coordination and specific protocols. Technological challenges mainly concern telecommunication networks. Conclusions: Specific adaptations will be necessary if regional telestroke networks are to include remote robotics. Some of these can already be put in place, which could greatly help the future implementation of the technology.

How to use the Contour intrasaccular device: two illustrative cases.

Contour (Stryker, Kalamazoo, MI) is a relatively new endosaccular device for the treatment of intracranial aneurysms.1 2 Its unique cup-like shape permits treatment of most lesions, including wide-necked, irregular, and shallowed-shaped aneurysms. The sizing of the device only requires two parameters: neck size and equatorial plane (width). It must be positioned at the neck of the aneurysm with the device proximal marker in the parent artery. In our experience, dual antiplatelet therapy is usually not required for intrasaccular devices and this is also an advantage of the Contour device. We report two illustrative cases of wide-neck aneurysms in the anterior and posterior circulation, respectively (video 1). In this video we demonstrate the feasibility of this treatment in a middle cerebral artery bifurcation with atypical triangular shape and typical tip-basilar aneurysm. neurintsurg;16/3/225/V1F1V1Video 1 .

Endovascular treatment of wide-neck bifurcation aneurysms: the eCLIPs device.

The endovascular clip system device, eCLIPs (eVasc, Vancouver, British Columbia, Canada), was introduced almost a decade ago for the treatment of wide-neck bifurcation aneurysms,1-3 which represent a challenge for both endovascular and surgical approaches. Several techniques and devices (intrasaccular or intra-arterial) have been introduced and are currently available in order to improve the technical and clinical outcomes of aneurysm embolization. Flow diversion and flow disruption have shown controversial results in this subtype of aneurysm. In this video we present the use of the eCLIPs device to treat a ruptured, wide-neck aneurysm of the top of the basilar artery. The decisional approach, technical details, and the different steps of the endovascular treatment are described. The final part of the video is dedicated to the characteristics of the device for re-endothelialization4 and flow diversion (video 1).5 neurintsurg;16/3/229/V1F1V1Video 1 .

Deep learning-based cerebral aneurysm segmentation and morphological analysis with three-dimensional rotational angiography.

BACKGROUND: The morphological assessment of cerebral aneurysms based on cerebral angiography is an essential step when planning strategy and device selection in endovascular treatment, but manual evaluation by human raters only has moderate interrater/intrarater reliability. METHODS: We collected data for 889 cerebral angiograms from consecutive patients with suspected cerebral aneurysms at our institution from January 2017 to October 2021. The automatic morphological analysis model was developed on the derivation cohort dataset consisting of 388 scans with 437 aneurysms, and the performance of the model was tested on the validation cohort dataset consisting of 96 scans with 124 aneurysms. Five clinically important parameters were automatically calculated by the model: aneurysm volume, maximum aneurysm size, neck size, aneurysm height, and aspect ratio. RESULTS: On the validation cohort dataset the average aneurysm size was 7.9±4.6 mm. The proposed model displayed high segmentation accuracy with a mean Dice similarity index of 0.87 (median 0.93). All the morphological parameters were significantly correlated with the reference standard (all P<0.0001; Pearson correlation analysis). The difference in the maximum aneurysm size between the model prediction and reference standard was 0.5±0.7 mm (mean±SD). The difference in neck size between the model prediction and reference standard was 0.8±1.7 mm (mean±SD). CONCLUSION: The automatic aneurysm analysis model based on angiography data exhibited high accuracy for evaluating the morphological characteristics of cerebral aneurysms.

Novel, braided, self-expandable stent designed for the treatment of pulsatile tinnitus caused by intracranial venous stenosis: first-in-human experience and long-term outcomes.

BACKGROUND: Pulsatile tinnitus (PT) can be a disabling clinical condition, which may be caused by a sigmoid/transverse sinus stenosis (STSS). Intracranial venous stenting with off-label carotid or peripheral venous stents has been used successfully to treat this condition. We present the results of a cohort of patients presenting with PT treated with a novel, dedicated, braided stent for the endovascular treatment of STSS. METHODS: Twelve patients presenting with PT and associated STSS were treated at our institution (December 2022-June 2023). All clinical and procedural variables were prospectively collected. We used the Tinnitus Function Index (TFI) and the Tinnitus Handicap Inventory (THI) scores to assess the impact of PT on quality of life before and after the treatment (mean follow-up: 10.3 months). RESULTS: Twelve women (mean age: 44±16.5 years) presenting with PT and STSS were treated. Mean pretreatment TFI/THI scores were 78.8/77. The BosStent was successfully deployed in all patients. We experienced no intraprocedural/postoperative complications. Intra-stent angioplasty was performed in three cases. All patients reported a complete resolution of PT symptoms within 1 month and remained stable and PT-free at the last follow-up (mean posttreatment TFI/THI score: 7.1/5, p<0001). CONCLUSIONS: The BosStent was successfully used in a cohort of patients with PT without any intraprocedural complications. All the patients experienced a complete resolution of PT symptoms after 1 month, which was stable during the follow-up period. Further studies with larger populations will be necessary to investigate the safety and effectiveness of this novel stent for the treatment of PT with STSS.

Stent-assisted Woven EndoBridge embolization for the treatment of pulsatile tinnitus caused by an ipsilateral high-riding jugular bulb.

PURPOSE: Pulsatile tinnitus can be caused by a high-riding jugular bulb (HRJB), characterized by the superior position of the jugular bulb in the petrous temporal bone. The anatomical position and morphology of this entity make it challenging for endovascular treatment. We report our experience with two patients successfully treated with a stent-assisted Woven EndoBridge (WEB; Microvention, Tustin, CA, USA) device. MATERIALS AND METHODS: We describe two cases of HRJB in patients presenting with disabling pulsatile tinnitus. Temporary balloon occlusion of the jugular bulb prior to the intervention reduced tinnitus intensity. Both patients were subsequently treated under general anesthesia with the WEB device deployed in the HRJB which was held by a stent deployed in the sigmoid sinus. RESULTS: Both procedures were successful with good positioning of the WEB device and no procedural complications. Both patients had complete resolution of pulsatile tinnitus immediately after the procedure. Follow-up imaging showed successful occlusion of the venous cavity with a widely patent stent. CONCLUSION: Among patients with pulsatile tinnitus caused by an ipsilateral HRJB, a stent-assisted WEB device seems to be a viable endovascular option with angiographic and clinical success.

Rescue intracranial permanent stenting for refractory occlusion following thrombectomy: a propensity matched analysis.

BACKGROUND: Rescue intracranial stenting (RIS) can be used in refractory large vessel occlusion (LVO) after mechanical thrombectomy (MT). We aimed to assess the safety and efficacy of RIS versus a propensity matched sample of patients with persistent LVO. METHODS: We retrospectively analysed a multicenter retrospective pooled cohort of patients with anterior LVO (2015-2021) treated with MT, and identified patients with at least three passes and a modified Thrombolysis In Cerebral Infarction (mTICI) score of 0 to 2a. Propensity score matching was used to account for determinants of outcome in patients with or without RIS. The study outcomes included 3 months modified Rankin Scale (mRS) and symptomatic hemorrhagic transformation (HT). RESULTS: 420 patients with a refractory anterior occlusion were included, of which 101 were treated with RIS (mean age 69 years). Favorable outcome (mRS 0-2) was more frequent in patients with a patent stent at day 1 (53% vs 6%, P<0.001), which was independently associated with an early dual antiplatelet regimen (P<0.05). In the propensity matched sample, patients treated with RIS versus without RIS had similar rates of favorable outcomes (36.8% vs 30.3%, P=0.606). Patients with RIS showed a favorable shift in the overall mRS distributions (common adjusted OR 0.74, 95% CI 0.60 to 0.91, P=0.006). Symptomatic HT was marginally more frequent in the RIS group (9% vs 3%, P=0.07), and there was no difference in 3-month mortality. CONCLUSION: In selected patients with a refractory intracranial occlusion despite at least three thrombectomy passes, RIS may be associated with an overall shift towards more favorable clinical outcome, and no significant increase in the odds of symptomatic HT or death.

Endosaccular flow disruption with the Contour Neurovascular System: angiographic and clinical results in a single-center study of 60 unruptured intracranial aneurysms.

BACKGROUND: The Contour Neurovascular System is a novel device designed to treat intracranial aneurysms by intrasaccular flow disruption. We report our experience and mid-term follow-up in a series of patients treated with the Contour. METHODS: The patients were divided into an intention to treat and a per protocol population, the latter defined by the successful implantation of the Contour device. The intention to treat population included 53 patients (30 women, mean age 56 years) with 60 unruptured intracranial aneurysms (53 in the anterior circulation and seven in the posterior circulation). There was clinical and angiographic follow-up immediate postoperatively and at 24 hours, 3 months and 1 year using the Raymond-Roy classification and the O'Kelly-Marotta grading scale. RESULTS: The Contour was successfully implanted in 54/60 (90%) aneurysms. With regard to the angiographic follow-up, there was adequate occlusion (defined as complete occlusion or presence of a neck remnant) in 31.5% of 54 aneurysms immediately postoperatively, 62.3% (in 53/54 aneurysms) at 24 hours, 81.4% (in 43/54 aneurysms) at 3 months, and 89.3% (in 28/54 aneurysms) at 1 year. Technical complications in 60 aneurysms of the intention to treat population included two (3.3%) inadvertent detachments of the device. Thromboembolic events were observed in four of the 60 aneurysms (6.7%), with no clinical symptoms in three patients and transient morbidity in one (1.7%). No aneurysm bleeding was observed and no patient was retreated during the 1-year follow-up period. There was no permanent morbidity or mortality. CONCLUSIONS: The Contour device is effective and safe in the treatment of intracranial aneurysms. However, more experience and long-term follow-up are needed.