Most Promising Approaches to Improve Brain AVM Management: ARISE I Consensus Recommendations.

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

ARISE I Consensus Review on the Management of Intracranial Aneurysms.

BACKGROUND: Intracranial aneurysms (IAs) remain a challenging neurological diagnosis associated with significant morbidity and mortality. There is a plethora of microsurgical and endovascular techniques for the treatment of both ruptured and unruptured aneurysms. There is no definitive consensus as to the best treatment option for this cerebrovascular pathology. The Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts discussed best practices and the most promising approaches to improve the management of brain aneurysms. METHODS: A group of experts from academia, industry, and federal regulators convened to discuss updated clinical trials, scientific research on preclinical system models, management options, screening and monitoring, and promising novel device technologies, aiming to improve the outcomes of patients with IA. RESULTS: Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts suggested the incorporation of artificial intelligence to capture sequential aneurysm growth, identify predictors of rupture, and predict the risk of rupture to guide treatment options. The consensus strongly recommended nationwide systemic data collection of unruptured IA radiographic images for the analysis and development of machine learning algorithms for rupture risk. The consensus supported centers of excellence for preclinical multicenter trials in areas such as genetics, cellular composition, and radiogenomics. Optical coherence tomography and magnetic resonance imaging contrast-enhanced 3T vessel wall imaging are promising technologies; however, more data are needed to define their role in IA management. Ruptured aneurysms are best managed at large volume centers, which should include comprehensive patient management with expertise in microsurgery, endovascular surgery, neurology, and neurocritical care. CONCLUSIONS: Clinical and preclinical studies and scientific research on IA should engage high-volume centers and be conducted in multicenter collaborative efforts. The future of IA diagnosis and monitoring could be enhanced by the incorporation of artificial intelligence and national radiographic and biologic registries. A collaborative effort between academic centers, government regulators, and the device industry is paramount for the adequate management of IA and the advancement of the field.

The paleolacustrine significance of sedimentary nitrogen isotopes: A comparative study of late Holocene records in two lakes on the eastern Qinghai-Tibet Plateau.

The bulk nitrogen isotope composition of lacustrine sediments can be a useful proxy of past climatic and environmental changes. We previously reconstructed paleoenvironmental histories recorded in sediments of Lake Ximencuo and Lake Ngoring, both located on the eastern Qinghai-Tibetan Plateau (QTP), using a suite of biogeochemical paleoclimate proxies that included the sedimentary δ15Ntot values. We have revisited the different patterns of δ15Ntot variations in the two lakes and now conclude that their isotopic trends over the last millennium have been controlled by multiple factors. Regional temperature evidently is one potential factor affecting the sedimentary δ15Ntot values, indicating that the lake ecosystems respond to regional temperature changes on a sub-millennial timescale but in indirect and lake-specific ways. The processes involved in the sedimentary δ15Ntot changes appear to be more strongly influenced by the shapes of lake basins and associated hydrologic characteristics that control the origins of nitrogen-containing compounds in the lakes. To help understand the dynamics of nitrogen cycling and nitrogen isotope records in the QTP lakes, we identified two patterns - a terrestrial nitrogen-controlled pattern (TNCP) that is observed in deeper, steep-walled glacial-basin lakes and an aquatic nitrogen-controlled pattern (ANCP) that is observed in shallower, tectonic-basin lakes. We also considered the influences of the "amount effect" and the "temperature effect" on sedimentary δ15Ntot values and their possible operative mechanisms in these montane lakes. We postulate that both patterns are applicable to the QTP lakes, including both glacial and tectonic lakes, and probably to lakes in other regions that have also not experienced significant human disturbance.

Treatment of large and giant posterior communicating artery aneurysms with the Surpass streamline flow diverter: results from the SCENT trial.

BACKGROUND: The Surpass flow diverter was developed to treat intracranial aneurysms not amenable to standard treatment. Indications for use allow placement in the internal carotid artery to the terminus, including the communicating artery segment. METHODS: The Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms (SCENT) trial is an international, multicenter, prospective, non-randomized trial comparing the outcomes of Surpass flow diverter treatment with historic control designed to evaluate the effectiveness and safety of Surpass for the treatment of wide neck (≥4 mm) large or giant intracranial aneurysms ≥10 mm. The primary effectiveness endpoint is the percentage of subjects with 100% aneurysm occlusion without significant stenosis of the parent artery and without retreatment of the target aneurysm at 12 months. The primary safety endpoint is the percentage of subjects experiencing neurologic death or major ipsilateral stroke at 12 months. We report the effectiveness and safety of flow diversion in the subgroup of posterior communicating artery (PComA) aneurysms. RESULTS: Of the 180 patients treated, 38 harbored a PComA aneurysm. Mean aneurysm size was 12.2 mm and mean neck width was 4.8 mm. The mean number of Surpass devices used was 1.1 per procedure, with 94.7% of aneurysms treated with one flow diverter. The 12 month primary effectiveness rate was 73.7% (28/38). At 36 months, 68.4% (26/38) of aneurysms remained completely occluded. The 12 month major ipsilateral stroke or neurological death rate was 10.5%. No patients with PComA occlusion after flow diverter placement (54.5%) had clinical sequelae. CONCLUSIONS: SCENT demonstrated acceptable 12 month effectiveness of flow diversion in PComA aneurysms. Despite associated PComA occlusions in many cases, arterial occlusions were clinically silent. TRIAL REGISTRATION NUMBER: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT01716117.

Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms - SCENT: 3-year outcomes.

BACKGROUND: To report the 3-year safety and effectiveness of the Surpass Streamline flow diverter in the SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms). METHODS: The Surpass Streamline flow diverter device was evaluated in a multicenter, prospective, single-arm, non-randomized interventional trial including patients with uncoilable or previously treated but failed aneurysms of the intracranial internal carotid artery. 3-year outcomes were tabulated with descriptive statistics and compared with 1-year outcomes. RESULTS: Of 180 patients in the modified intent-to-treat (mITT) cohort, 36-month clinical and angiographic follow-up was available in 134 and 117 cases, respectively. Effectiveness endpoint of complete aneurysm occlusion without clinically significant stenosis or retreatment was met in 71.8% (79/110, 95% CI 62.4% to 80.0%) of cases. Safety composite endpoint was 12.2% (22/180) over the 3-year period, with two major safety events (ipsilateral ischemic strokes) occurring between 12-36 months. Complete aneurysm occlusion was noted in 77.8% (91/117), and 99.1% (116/117) of the patients demonstrated adequate aneurysm occlusion (complete occlusion or neck residual). There were four cases (2.2%) of aneurysm rupture, all occurring within the first month of the index procedure. Target aneurysm retreatment rate was 2.8% (5/180). CONCLUSION: The present findings support the long-term safety and effectiveness of the Surpass Streamline flow diverter device. TRIAL REGISTRATION: NCT01716117.

Significance of different n-alkane biomarker distributions in four same-age peat sequences around the edges of a small maar lake in China.

A decade-resolution study of peat cores from four different locations around Yuanchi Lake, a small shallow maar lake in the Changbai Mountains of northeastern China, has established that peat deposition around this lake amplified at ca. 1800 CE with accumulation rates that differ among the four closely spaced sites. Comparisons of the n-alkane distributions of typical plants and the distributions in the peat cores indicate that the differences in the n-alkane contents at the four sites around the lake are consequences of differences in the peat-forming plant communities that have developed on the lake edges. These floral differences likely resulted from different littoral water depths from small but significant variations in bottom topography around the lake, compounded by progressive infilling of the edges at different rates as peat accumulated. Moreover, several n-alkane-inferred variations in peat accumulation rates from 1800 to 1950 CE are common to the four sites and appear to reflect local cold and dry periods. We infer that these periods are associated with nearby volcanic eruptions in the Changbai Mountains and possibly to distal eruptions in the tropical Pacific. Since 1950 CE, decreases in peat accumulations around the lake may result from enhanced peat decomposition as the water table declined in response to a warm and dry climate and to anthropogenic impacts on the lake catchment.

Safety of the APOLLO Onyx delivery microcatheter for embolization of brain arteriovenous malformations: results from a prospective post-market study.

BACKGROUND: Catheter retention and difficulty in retrieval have been observed during embolization of brain arteriovenous malformations (bAVMs) with the Onyx liquid embolic system (Onyx). The Apollo Onyx delivery microcatheter (Apollo) is a single lumen catheter designed for controlled delivery of Onyx into the neurovasculature, with a detachable distal tip to aid catheter retrieval. This study evaluates the safety of the Apollo for delivery of Onyx during embolization of bAVMs. METHODS: This was a prospective, non-randomized, single-arm, multicenter, post-market study of patients with a bAVM who underwent Onyx embolization with the Apollo between May 2015 and February 2018. The primary endpoint was any catheter-related adverse event (AE) at 30 days, such as unintentional tip detachment or malfunction with clinical sequelae, or retained catheter. Procedure-related AEs (untoward medical occurrence, disease, injury, or clinical signs) and serious AEs (life threatening illness or injury, permanent physiological impairment, hospitalization, or requiring intervention) were also recorded. RESULTS: A total of 112 patients were enrolled (mean age 44.1±17.6 years, 56.3% men), and 201 Apollo devices were used in 142 embolization procedures. The mean Spetzler-Martin grade was 2.38. The primary endpoint was not observed (0/112, 0%). The catheter tip detached during 83 (58.5%) procedures, of which 2 (2.4%) were unintentional and did not result in clinical sequelae. At 30 days, procedure related AEs occurred in 26 (23.2%) patients, and procedure-related serious AEs in 12 (10.7%). At 12 months, there were 3 (2.7%) mortalities, including 2 (1.8%) neurological deaths, none of which were device-related. CONCLUSION: This study demonstrates the safety of Apollo for Onyx embolization of bAVMs. CLINICAL TRIAL REGISTRATION: CNCT02378883.

Delayed-Onset Cranial Nerve Palsy After Transvenous Embolization of Indirect Carotid Cavernous Fistulas.

BACKGROUND: Carotid cavernous fistulas (CCF) often present with diplopia secondary to cranial nerve palsy (CNP). Immediate development of postoperative CNP has been described in the literature. This study described delayed-onset of CNP after complete and reconfirmed obliteration of the CCF and resolution of initial CNP. METHODS: A retrospective analysis was performed on patients with indirect CCF between 1987 and 2006 at 4 academic endovascular centers. Details of the endovascular procedures, embolic agents used, and complications were studied. Partial or complete obliteration was determined. Immediate and delayed cranial nerve palsies were independently assessed. RESULTS: A total of 267 patients with symptomatic indirect CCF underwent transvenous endovascular treatment. Four patients (1.5%) developed delayed abducens nerve (VI) palsy after complete resolution of presenting symptoms after embolization. Delayed presentation ranged between 3 and 13 months after complete resolution of initial double vision and cranial nerve palsies. Transvenous coil embolization through the inferior petrosal sinus was performed in all 4 affected patients. All had follow-up angiography confirming durable closure of their CCF. MRI did not show new mass lesions or abnormal soft tissue enhancement. In all 4 patients, their abducens nerve (VI) palsy remained. CONCLUSIONS: Delayed CNP can develop despite complete endovascular obliteration of the CCF. The cause of delayed CNP is not yet determined, but may represent fibrosis and ischemia. Long-term follow-up is needed even after complete neurological and radiological recovery is attained in the immediate perioperative period.

Stroke and mechanical thrombectomy in patients with COVID-19: technical observations and patient characteristics.

BACKGROUND: COVID-19 infections have been shown to be associated with a range of thromboembolic disease. OBJECTIVE: To describe our endovascular experience in a consecutive series of patients with COVID-19 who presented with large vessel occlusions, and to describe unique findings in this population. METHODS: Mechanical thrombectomy was performed on five consecutive patients with COVID-19 with large vessel occlusions. A retrospective study of these patients was performed. Patient demographics, laboratory values, mechanical thrombectomy technique, and clinical and angiographic outcomes were reviewed. RESULTS: Four patients with COVID-19 presented with anterior circulation occlusions and one patient with COVID-19 presented with both anterior and posterior circulation occlusions. All patients had coagulation abnormalities. Mean patient age was 52.8 years. Three patients presented with an intracranial internal carotid artery occlusion. Two patients presented with an intracranial occlusion and a tandem thrombus in the carotid bulb. One patient presented with an occlusion in both the internal carotid and basilar arteries. Clot fragmentation and distal emboli to a new vascular territory were seen in two of five (40%) patients, and downstream emboli were seen in all five (100%) patients. Patient clinical outcome was generally poor in this series of patients with COVID-19 large vessel occlusion. CONCLUSION: Our series of patients with COVID-19 demonstrated coagulation abnormalities, and compared with our previous experience with mechanical thrombectomy in large vessel occlusion, this group of patients were younger, had tandem or multiple territory occlusions, a large clot burden, and a propensity for clot fragmentation. These patients present unique challenges that make successful revascularization difficult.

Bailout Strategies and Complications Associated with the Use of Flow-Diverting Stents for Treating Intracranial Aneurysms.

BACKGROUND: Flow-diverting stents (FDS) have revolutionized the endovascular management of unruptured, complex, wide-necked, and giant aneurysms. There is no consensus on management of complications associated with the placement of these devices. This review focuses on the management of complications of FDS for the treatment of intracranial aneurysms. SUMMARY: We performed a systematic, qualitative review using electronic databases MEDLINE and Google Scholar. Complications of FDS placement generally occur during the perioperative period. KEY MESSAGE: Complications associated with FDS may be divided into periprocedural complications, immediate postprocedural complications, and delayed complications. We sought to review these complications and novel management strategies that have been reported in the literature.

Mandatory Neuroendovascular Evolution: Meeting the New Demands.

BACKGROUND: Traditionally, patients undergoing acute ischemic strokes were candidates for mechanical thrombectomy if they were within the 6-h window from onset of symptoms. This timeframe would exclude many patient populations, such as wake-up strokes. However, the most recent clinical trials, DAWN and DEFUSE3, have expanded the window of endovascular treatment for acute ischemic stroke patients to within 24 h from symptom onset. This expanded window increases the number of potential candidates for endovascular intervention for emergent large vessel occlusions and raises the question of how to efficiently screen and triage this increase of patients. SUMMARY: Abbreviated pre-hospital stroke scales can be used to guide EMS personnel in quickly deciding if a patient is undergoing a stroke. Telestroke networks connect remote hospitals to stroke specialists to improve the transportation time of the patient to a comprehensive stroke center for the appropriate level of care. Mobile stroke units, mobile interventional units, and helistroke reverse the traditional hub-and-spoke model by bringing imaging, tPA, and expertise to the patient. Smartphone applications and social media aid in educating patients and the public regarding acute and long-term stroke care. KEY MESSAGES: The DAWN and DEFUSE3 trials have expanded the treatment window for certain acute ischemic stroke patients with mechanical thrombectomy and subsequently have increased the number of potential candidates for endovascular intervention. This expansion brings patient screening and triaging to greater importance, as reducing the time from symptom onset to decision-to-treat and groin puncture can better stroke patient outcomes. Several strategies have been employed to address this issue by reducing the time of symptom onset to decision-to-treat time.

Curative treatment for low-grade arteriovenous malformations.

BACKGROUND: Spetzler-Martin (SM) grade I-II (low-grade) arteriovenous malformations (AVMs) are often considered safe for microsurgery or radiosurgery. The adjunctive use of preoperative embolization to reduce surgical risk in these AVMs remains controversial. OBJECTIVE: To assess the safety of combined treatment of grade I-II AVMs with preoperative embolization followed by surgical resection or radiosurgery, and determine the long-term functional outcomes. METHODS: With institutional review board approval, a retrospective analysis was carried out on patients with ruptured and unruptured SM I-II AVMs between 2002 and 2017. Details of the endovascular procedures, including number of arteries supplying the AVM, number of branches embolized, embolic agent(s) used, and complications were studied. Baseline clinical and imaging characteristics were compared. Functional status using the modified Rankin Scale (mRS) before and after endovascular and microsurgical treatments was compared. RESULTS: 258 SM I-II AVMs (36% SM I, 64% SM II) were identified in patients with a mean age of 38 ± 17 years. 48% presented with hemorrhage, 21% with seizure, 16% with headache, 10% with no symptoms, and 5% with clinical deficits. 90 patients (68%) in the unruptured group and 74 patients (59%) in the ruptured group underwent presurgical embolization (p = 0.0013). The mean number of arteries supplying the AVM was 1.44 and 1.41 in the unruptured and ruptured groups, respectively (p = 0.75). The mean number of arteries embolized was 2.51 in the unruptured group and 1.82 in the ruptured group (p = 0.003). n-Butyl cyanoacrylate and Onyx were the two most commonly used embolic agents. Four complications were seen in four patients (4/164 patients embolized): two peri-/postprocedural hemorrhage, one dissection, and one infarct. All patients undergoing surgery had a complete cure on postoperative angiography. Patients were followed up for a mean of 55 months. Good long-term outcomes (mRS score ≤ 2) were seen in 92.5% of patients with unruptured AVMs and 88.0% of those with ruptured AVMs. Permanent neurological morbidity occurred in 1.2%. CONCLUSIONS: Curative treatment of SM I-II AVMs can be performed using endovascular embolization with microsurgical resection or radiosurgery in selected cases, with very low morbidity and high cure rates. Compared with other published series, these outcomes suggest that preoperative embolization is a safe and effective adjunct to definitive surgical treatment. Long-term follow-up showed that patients with low-grade AVMs undergoing surgical resection or radiosurgery have good functional outcomes.

A Contemporary Review of Endovascular Treatment of Wide-Neck Large and Giant Aneurysms.

BACKGROUND: Despite widespread use of flow diverters, wide-necked large and giant aneurysms are still treated with other techniques as well. A contemporary review of results from different endovascular treatments is timely. METHODS: A literature review of the English language literature since 2011 was conducted using PubMed and Science Direct. Keywords and Medical Subheadings included large and giant aneurysms, ruptured aneurysms, aneurysms located in posterior circulation, and aneurysm occlusion status. Case reports were excluded. A combined model was built including both flow diverter and coil treatments in addition to separate models. Efficacy and safety were pooled using random effects analysis and regression. RESULTS: The review comprised 29 studies. For coiling techniques, complete occlusion was 40.2%-82.8%, and adjusted regression resulted in 53% (95% confidence interval [CI] 22%-81%). Flow diverter complete occlusion rate was 40.5%-87.8%, and adjusted regression resulted in 87% (95% CI 76%-93%). Overall occlusion rate for both techniques combined was 62%-75%, and adjusted regression resulted in 81% (95% CI 68%-89%). Overall stroke and death regression rate was 5% (95% CI 3%-10%); flow diverters showed slightly higher rates than coiling (6% vs. 3%). CONCLUSIONS: All current treatments of large and giant wide-necked aneurysms have comparable safety and efficacy with a trend of superiority of efficacy toward flow diverters. Results of future treatment options and devices can be compared with current technology to evaluate feasibility.

Definition and Prioritization of Data Elements for Cohort Studies and Clinical Trials on Patients with Unruptured Intracranial Aneurysms: Proposal of a Multidisciplinary Research Group.

INTRODUCTION: Variability in usage and definition of data characteristics in previous cohort studies on unruptured intracranial aneurysms (UIA) complicated pooling and proper interpretation of these data. The aim of the National Institute of Health/National Institute of Neurological Disorders and Stroke UIA and Subarachnoid Hemorrhage (SAH) Common Data Elements (CDE) Project was to provide a common structure for data collection in future research on UIA and SAH. METHODS: This paper describes the development and summarization of the recommendations of the working groups (WGs) on UIAs, which consisted of an international and multidisciplinary panel of cerebrovascular specialists on research and treatment of UIAs. Consensus recommendations were developed by review of previously published CDEs for other neurological diseases and the literature on UIAs. Recommendations for CDEs were classified by priority into 'Core,' 'Supplemental-Highly Recommended,' 'Supplemental,' and 'Exploratory.' RESULTS: Ninety-one CDEs were compiled; 69 were newly created and 22 were existing CDEs. The CDEs were assigned to eight subcategories and were classified as Core (8), Supplemental-Highly Recommended (23), Supplemental (25), and Exploratory (35) elements. Additionally, the WG developed and agreed on a classification for aneurysm morphology. CONCLUSION: The proposed CDEs have been distilled from a broad pool of characteristics, measures, or outcomes. The usage of these CDEs will facilitate pooling of data from cohort studies or clinical trials on patients with UIAs.

Current endovascular strategies for posterior circulation large vessel occlusion stroke: report of the Society of NeuroInterventional Surgery Standards and Guidelines Committee.

BACKGROUND: The aim of this publication is to provide a detailed update on the diagnosis, treatment, and endovascular techniques for posterior circulation emergent large vessel occlusion (pc-ELVO). METHODS: We performed a review of the literature to specifically evaluate this disease and its treatments. RESULTS: Data were analyzed, and recommendations were reported based on the strength of the published evidence and expert consensus. CONCLUSION: While many questions about pc-ELVO remain to be studied, there is evidence to support particular practices in its evaluation and treatment.

SCENT Trial.

Background and Purpose- To evaluate the safety and effectiveness of the Surpass Flow Diverter (Surpass; Stryker Neurovascular, Fremont, CA) in the treatment of large or giant wide-neck intracranial aneurysms at one year, we hypothesize that treatment with Surpass meets or improves on historical safety and efficacy end points. Methods- SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms) is a multicenter, prospective, single-arm, nonrandomized, interventional trial of the Surpass Flow Diverter for uncoilable or previously treated but failed aneurysms of the intracranial internal carotid artery extending from the petrous segment to the carotid terminus at its bifurcation into anterior and middle cerebral arteries. For enrollment in SCENT, target aneurysms had to be wide-neck (≥4 mm) and large or giant size (≥10 mm). Study results are compared with performance goals derived from a thorough review of the medical literature. The primary effectiveness end point included 3 components: complete aneurysm occlusion, absence of significant parent artery stenosis (≥50%), and no retreatment at 12 months. The primary safety end point was major ipsilateral stroke (increase in National Institutes of Health Stroke Scale score of ≥4) or neurological death within 12 months. Results- At 26 medical centers, 180 patients with 180 target aneurysms were enrolled in the modified intention-to-treat cohort. Per angiographic core lab assessment, there were 15 (8.3%) fusiform, 164 (91.1%) saccular aneurysms, and 1 (0.6%) blister aneurysm. Mean aneurysm size was 12.0 mm. Thirteen (7.4%) aneurysms were giant (≥25 mm). Fifty-eight (32.2%) aneurysms were located in the supraclinoid and distal (including posterior communicating artery) segments of the internal carotid artery. Mean procedure duration was 53.6 minutes. The device was successfully implanted in 97.8% of patients with a mean of 1.1 devices per patient. SCENT met both primary safety and effectiveness end points: 12-month primary effectiveness rate was 62.8% [(113/180); 95% CI, 55.3-69.9] and 12-month major ipsilateral stroke or neurological death rate was 8.3% [(15/180); 95% CI, 4.7-13.4]. Conclusions- Surpass provides safe and effective flow diversion of large or giant, wide-neck, intracranial internal carotid artery aneurysms. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01716117.

Common Data Elements for Radiological Imaging of Patients with Subarachnoid Hemorrhage: Proposal of a Multidisciplinary Research Group.

INTRODUCTION: Lack of homogeneous definitions for imaging data and consensus on their relevance in the setting of subarachnoid hemorrhage and unruptured intracranial aneurysms lead to a difficulty of data pooling and lack of robust data. The aim of the National Institute of Health/National Institute of Neurological Disorders and Stroke, Unruptured Intracranial Aneurysm (UIA) and Subarachnoid Hemorrhage (SAH) Common Data Elements (CDE) Project was to standardize data elements to ultimately facilitate data pooling and establish a more robust data quality in future neurovascular research on UIA and SAH. METHODS: For the subcommittee 'Radiological imaging of SAH,' international cerebrovascular specialists with imaging expertise in the setting of SAH were selected by the steering committee. CDEs were developed after reviewing the literature on neuroradiology and already existing CDEs for other neurological diseases. For prioritization, the CDEs were classified into 'Core,' 'Supplemental-Highly Recommended,' 'Supplemental' and 'Exploratory.' RESULTS: The subcommittee compiled 136 CDEs, 100 out of which were derived from previously established CDEs on ischemic stroke and 36 were newly created. The CDEs were assigned to four main categories (several CDEs were assigned to more than one category): 'Parenchymal imaging' with 42 CDEs, 'Angiography' with 49 CDEs, 'Perfusion imaging' with 20 CDEs, and 'Transcranial doppler' with 55 CDEs. The CDEs were classified into core, supplemental highly recommended, supplemental and exploratory elements. The core CDEs were imaging modality, imaging modality type, imaging modality vessel, angiography type, vessel angiography arterial anatomic site and imaging vessel angiography arterial result. CONCLUSIONS: The CDEs were established based on the current literature and consensus across cerebrovascular specialists. The use of these CDEs will facilitate standardization and aggregation of imaging data in the setting of SAH. However, the CDEs may require reevaluation and periodic adjustment based on current research and improved imaging quality and novel modalities.