Objective To assess the relationship of the grade of unruptured and untreated Brain Arteriovenous Malformations (AVMs), with the risk of subsequent stroke and death during follow‐up. Methods This prospective study was drawn from a cohort of adult patients with unruptured AVMs, who participated in the conservative treatment arm (medical management only for headache or seizures) of the randomized clinical trial of unruptured brain AVMs (ARUBA study). The grade of AVMs (Spetzler–Martin scale) was dichotomized into categories: AVMs of grades I and II were considered low grade; AVMs of grades III and IV were considered high grade. There were no grade V AVM patients in ARUBA. The primary outcome was symptomatic stroke (hemorrhagic or ischemic – documented by imaging) or death. Results The conservative treatment group had 123 patients (“as treated” analysis). 71 (57.7%) had lesions characterized for this analysis as low‐grade lesions and 52 (42.2%) as high grade. From the total of 10 (8.13%) primary outcomes, three occurred (4.22%) in low‐grade AVMs and seven (13.46%) in high‐grade AVMs (P = 0.0942). Interpretation Statistical analysis of the cohort of patients with unruptured and untreated AVMs from ARUBA study showed that the graduation categories (Spetzler–Martin grades) were not associated with the outcome of subsequent stroke or death.

Introduction: Accurately balancing risks of interventional treatment and intracranial hemorrhage (ICH) in the untreated course of unruptured brain arteriovenous malformation (uBAVM) patients is critical for optimal management. Observational studies of uBAVM afford an opportunity to address important gaps and previous criticisms of randomized data to help guide treatment decisions and assess long-term risk/benefit ratio. We previously published an individual patient data meta-analysis (IPDMA) in 4 MARS cohorts and identified ICH presentation and increasing age as significant predictors of ICH during follow-up, but was not powered to detect predictors in those with uBAVM. Thus, the goals of this project are to identify risk factors for ICH in uBAVMs, to estimate the risk with precision, and to create personalized, risk-prediction models. Methods: MARS is an international, multi-center study of 11 cohorts with target enrollment of 4,500 uBAVM patients ascertained through population-based or referral-based studies. We are harmonizing both retrospective and prospective data, including clinical, lifestyle, imaging, and angiographic factors. Treatments, complications, and functional outcomes (physician and patient-reported) will be updated annually between 2018-2022. We propose to: 1) identify predictors of outcome in uBAVMs using IPDMA; 2) test whether long-term outcomes differ by treatment using statistical approaches for causal inference and unbiased estimates; 3) compare treatment outcomes in randomized and non-randomized data to address generalizability; and 4) validate models and provide a novel tool for calculating individualized risks. Eligible sites have: a) prior BAVM publications; b) data from a minimum of 100 uBAVM patients; c) agree to random outcome adjudication; and d) agree to MARS data sharing policy. Discussion: The NIH-funded MARS consortium will provide important and comprehensive characterization of the untreated and treated course of uBAVMs, using large observational datasets and sophisticated epidemiological approaches. The data and models generated will be a useful resource for decision-making. We welcome participation from eligible sites with longitudinal data on uBAVM patients

Introduction Temporal bone anatomy is complex and demands a profound anatomical knowledge. Association between surgery and imaging helps in the process of learning three-dimensional (3D) anatomy and surgical techniques. High definition temporal bone imaging can play an important role in dissection training. Objective To describe a computed tomography (CT) image-guided temporal bone dissection course for surgical training in otolaryngology and to verify the satisfaction level of the students with the course. Methods Descriptive research. The course took place at a research laboratory, with three experienced temporal bone surgeons. The participants were 12 otolaryngology residents. The laboratory has 7 modern workstations with microscope and monitors linked with a computerized video system. Cadaveric temporal bones were donated to the university. Imaging acquisition of the cadaveric temporal bones used in the course was performed in a multislice CT scanner. The CT images of cadaveric temporal bones were available with real-time access on the laboratory monitor's screens during dissections. Results A total of 13 temporal bones were included for dissection. Students had the opportunity to view on the same screen, simultaneously, both the dissection video and the respective CT images of their temporal bone anatomical specimens. This allowed correlating surgical and imaging aspects of temporal bone anatomy. At the end of the course, participants answered a satisfaction survey. Conclusion Considering imaging methods are routinely used during most otologic surgeries, detailed knowledge of CT imaging should be explored in conjunction with the temporal bone anatomical dissection.