Our Group's Purpose


We are focused on providing clinical excellence, innovation in research, and high-quality education. We aim to push the boundaries of neurovascular surgery for the benefit of our patients and the future generation of providers.

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Our Team

Our team consists of medical students, research and clinical fellows, and residents who are focused on bringing about innovation in neurovascular surgery.

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Featured Publications

  • Pettersson SD, Koga S, Ali S, Enríquez-Marulanda A, Taussky P, Ogilvy CS. Cerebral artery overexpression of the NMUR1 gene is associated with moyamoya disease: a weighted gene co-expression network analysis.. Cerebrovascular diseases (Basel, Switzerland). Published online 2024. doi:10.1159/000538035

    INTRODUCTION: This study aimed to elucidate mechanisms underlying moyamoya disease (MMD) pathogenesis and to identify potential novel biomarkers. We utilized gene coexpression networks to identify hub genes associated with the disease.

    METHODS: Twenty-one middle cerebral artery (MCA) samples from MMD patients and 11 MCA control samples were obtained from the Gene Expression Omnibus (GEO) dataset, GSE189993. To discover functional pathways and potential biomarkers, weighted gene coexpression network analysis (WGCNA) was employed. The hub genes identified were re-assessed through differential gene expression analysis (DGEA) via DESeq2 for further reliability verification. An additional 4 samples from the superficial temporal arteries (STA) from MMD patients were obtained from GSE141025 and a subgroup analysis stratified by arterial type (MCA vs. STA) DGEA was performed to assess if the hub genes associated with MMD are expressed significantly greater on the affected arteries compared to healthy ones in MMD.

    RESULTS: WGCNA revealed a predominant module encompassing 139 hub genes, predominantly associated with the neuroactive ligand-receptor interaction (NLRI) pathway. Of those, 17 genes were validated as significantly differentially expressed. Neuromedin U receptor 1 (NMUR1) and thyrotropin-releasing hormone (TRH) were 2 out of the 17 hub genes involved in the NLRI pathway (log fold change [logFC]: 1.150, p = 0.00028; logFC: 1.146, p = 0.00115, respectively). MMD-only subgroup analysis stratified by location showed that NMUR1 is significantly overexpressed in the MCA compared to the STA (logFC: 1.962; p = 0.00053) which further suggests its possible localized involvement in the progressive stenosis seen in the cerebral arteries in MMD.

    CONCLUSION: This is the first study to have performed WGCNA on samples directly affected by MMD. NMUR1 expression is well known to induce localized arterial smooth muscle constriction and recently, type 2 inflammation which can predispose to arterial stenosis potentially advancing the symptoms and progression of MMD. Further validation and functional studies are necessary to understand the precise role of NMUR1 upregulation in MMD and its potential implications.

  • Ramirez-Velandia F, Enríquez-Marulanda A, Filo J, et al. Comparison of Thromboembolic Events Between Pipeline Embolization Device (PED) Shield and PED/PED Flex: A Propensity Score-Matched Analysis.. Neurosurgery. Published online 2024. doi:10.1227/neu.0000000000002883

    BACKGROUND AND OBJECTIVES: The pipeline embolization device (PED) Flex with Shield technology is a third-generation flow diverter used for intracranial aneurysm treatment designed to decrease thrombogenicity through a phosphorylcholine coating. Herein, we aim to compare the rate of thromboembolic events in PED with Shield technology and PED without it through propensity score matching.

    METHODS: We conducted a retrospective analysis of aneurysms treated with PED first-generation/PED Flex and PED with Shield between 2013 and 2023 at a single academic institution. Patients were matched through propensity score by controlling for confounding factors including age, smoking history, diabetes, previous subarachnoid hemorrhage, modified Rankin Scale pretreatment, location, aneurysm size, previous treatment, and clopidogrel or aspirin resistance. After matching, we evaluated for periprocedural and postoperative thromboembolic events. Data analysis was performed using Stata 14.

    RESULTS: A total of 543 patients with 707 aneurysms treated in 605 procedures were included in the analysis. From these, 156 aneurysms were treated with PED with Shield (22.07%) and 551 (77.93%) without Shield technology. Propensity score matching resulted in 84 matched pairs. The rate of thromboembolic events was 3.57% for PED Shield and 10.71% for PED first-generation/PED Flex (P = .07), while retreatment rates were 2.38% for PED Shield and 8.32% for PED Flex (P = .09). Complete occlusion at first (P = .41) and last imaging follow-up (P = .71), in-stent stenosis (P = .95), hemorrhagic complications (P = .31), and functional outcomes (P = .66) were comparable for both groups.

    CONCLUSION: This is the first study in the literature performing a propensity scored-matched analysis comparing PED with PED with Shield technology. Our study suggests a trend toward lower thromboembolic events for PED Shield, even after controlling for aspirin and clopidogrel resistance, and a trend toward lower aneurysm retreatment rates with PED Shield, without reaching statistical significance.