Federal and foundational research funding trends for cerebrovascular neurosurgeons: the decline of the cerebrovascular surgeon-scientist?

Objective: The number of cerebrovascular (CV) surgeons has grown with the rise of endovascular neurosurgery. However, it is unclear whether the number of CV surgeon-scientists has concomitantly increased. With increasing numbers of CV neurosurgeons in the US workforce, the authors analyzed associated changes in National Institutes of Health (NIH) and Neurosurgery Research and Education Foundation (NREF) funding trends for CV surgeons over time.

Auricular Vagus Nerve Stimulation Mitigates Inflammation and Vasospasm in Subarachnoid Hemorrhage: A Randomized Trial.

Background: Inflammation contributes to morbidity following subarachnoid hemorrhage (SAH). Transauricular vagus nerve stimulation (taVNS) offers a noninvasive approach to target the inflammatory response following SAH.

Methods: In this prospective, triple-blinded, randomized, controlled trial, twenty-seven patients were randomized to taVNS or sham stimulation.

The effect of transcutaneous auricular vagus nerve stimulation on cardiovascular function in subarachnoid hemorrhage patients: a safety study.

Introduction: Subarachnoid hemorrhage (SAH) is characterized by intense central inflammation, leading to substantial post-hemorrhagic complications such as vasospasm and delayed cerebral ischemia. Given the anti-inflammatory effect of transcutaneous auricular vagus nerve stimulation (taVNS) and its ability to promote brain plasticity, taVNS has emerged as a promising therapeutic option for SAH patients. However, the effects of taVNS on cardiovascular dynamics in critically ill patients, like those with SAH, have not yet been investigated.

Non-invasive Auricular Vagus nerve stimulation for Subarachnoid Hemorrhage (NAVSaH): Protocol for a prospective, triple-blinded, randomized controlled trial.

Background: Inflammation has been implicated in driving the morbidity associated with subarachnoid hemorrhage (SAH). Despite understanding the important role of inflammation in morbidity following SAH, there is no current effective way to modulate this deleterious response. There is a critical need for a novel approach to immunomodulation that can be safely, rapidly, and effectively deployed in SAH patients.

Comparative cost analysis of endovascular and open approaches for elective treatment of middle cerebral artery aneurysms.

Background: Intracranial aneurysms of the middle cerebral artery can be treated using several open surgical and endovascular approaches. Given the growing evidence of clinical equipoise between these various treatment strategies, there is a need to assess the costs associated with each.

Methods: Cost of aneurysm treatment was divided into two categories for comparison.

Peripheral macrophages in the development and progression of structural cerebrovascular pathologies.

The human cerebrovascular system is responsible for maintaining neural function through oxygenation, nutrient supply, filtration of toxins, and additional specialized tasks. While the cerebrovascular system has resilience imparted by elaborate redundant collateral circulation from supportive tertiary structures, it is not infallible, and is susceptible to developing structural vascular abnormalities. The causes of this class of structural cerebrovascular diseases can be broadly categorized as 1) intrinsic developmental diseases resulting from genetic or other underlying aberrations (arteriovenous malformations and cavernous malformations) or 2) extrinsic acquired diseases that cause compensatory mechanisms to drive vascular remodeling (aneurysms and arteriovenous fistulae).

In-hospital imaging utilization after elective endovascular brain aneurysm treatment: a surrogate metric for the value of hospitalization.

Objective: Despite the adoption of same-day outpatient surgical procedures in some specialties, it remains common practice to admit patients for monitoring after elective endovascular treatment of brain aneurysms to monitor for complications. The necessity of such monitoring has not been fully characterized. Here, the authors reviewed the utilization of imaging during posttreatment hospitalization, a surrogate measure for workup of suspected complications requiring hospital resources, to infer the value of inpatient monitoring after endovascular aneurysm treatment.

Isoflurane Conditioning-Induced Delayed Cerebral Ischemia Protection in Subarachnoid Hemorrhage-Role of Inducible Nitric Oxide Synthase.

Background Recent evidence implicates inflammation as a key driver in delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage (SAH). Inducible nitric oxide synthase (iNOS) is one of the known major mediators of inflammation. We previously showed that an inhalational anesthetic, isoflurane, provides strong protection against delayed cerebral ischemia after SAH.

Isoflurane Conditioning Provides Protection against Subarachnoid Hemorrhage Induced Delayed Cerebral Ischemia through NF-kB Inhibition.

Delayed cerebral ischemia (DCI) is the largest treatable cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Nuclear Factor Kappa-light-chain-enhancer of Activated B cells (NF-kB), a transcription factor known to function as a pivotal mediator of inflammation, is upregulated in SAH and is pathologically associated with vasospasm. We previously showed that a brief exposure to isoflurane, an inhalational anesthetic, provided multifaceted protection against DCI after SAH.

A review of technological innovations leading to modern endovascular brain aneurysm treatment.

Tools and techniques utilized in endovascular brain aneurysm treatment have undergone rapid evolution in recent decades. These technique and device-level innovations have allowed for treatment of highly complex intracranial aneurysms and improved patient outcomes. We review the major innovations within neurointervention that have led to the current state of brain aneurysm treatment.

A pilot study of lymphoscintigraphy with tracer injection into the human brain.

Many groups have reported lymphatic and glymphatic structures in animal and human brains, but tracer injection into the human brain to demonstrate real-time lymphatic drainage and mapping has not been described. We enrolled patients undergoing standard-of-care resection or stereotactic biopsy for suspected intracranial tumors. Patients received peritumoral injections of Tc-tilmanocept followed by planar or tomographic imaging.

Early Brain Injury After Subarachnoid Hemorrhage: Incidence and Mechanisms.

Aneurysmal subarachnoid hemorrhage is a devastating condition causing significant morbidity and mortality. While outcomes from subarachnoid hemorrhage have improved in recent years, there continues to be significant interest in identifying therapeutic targets for this disease. In particular, there has been a shift in emphasis toward secondary brain injury that develops in the first 72 hours after subarachnoid hemorrhage.

Surgery for Pituitary Tumor Apoplexy Is Associated with Rapid Headache and Cranial Nerve Improvement.

Pituitary tumor apoplexy (PTA) classically comprises sudden-onset headache, loss of vision, ophthalmoparesis, and decreased consciousness. It typically results from hemorrhage and/or infarction within a pituitary adenoma. Presentation is heterologous, and optimal management is debated.

SIRT1 mediates hypoxic postconditioning- and resveratrol-induced protection against functional connectivity deficits after subarachnoid hemorrhage.

Functional connectivity (FC) is a sensitive metric that provides a readout of whole cortex coordinate neural activity in a mouse model. We examine the impact of experimental SAH modeled through endovascular perforation, and the effectiveness of subsequent treatment on FC, through three key questions: 1) Does the endovascular perforation model of SAH induce deficits in FC; 2) Does exposure to hypoxic conditioning provide protection against these FC deficits and, if so, is this neurovascular protection SIRT1-mediated; and 3) does treatment with the SIRT1 activator resveratrol alone provide protection against these FC deficits? Cranial windows were adhered on skull-intact mice that were then subjected to either sham or SAH surgery and either left untreated or treated with hypoxic post-conditioning (with or without EX527) or resveratrol for 3 days. Mice were imaged 3 days post-SAH/sham surgery, temporally aligned with the onset of major SAH sequela in mice.

Endovascular Treatment of Acute Stroke.

Purpose Of Review: In the USA, around 30% of 795,000 strokes per year are due to proximal large-vessel occlusion, and these are a major cause of death and disability. We review the most recent advances regarding treatment of ischemic stroke amenable to mechanical thrombectomy.

Recent Findings: In the last four years, clinical trial evidence has expanded the time window for successful endovascular treatment to 24 h.

Inhalational Versus Intravenous Anesthetic Conditioning for Subarachnoid Hemorrhage-Induced Delayed Cerebral Ischemia.

Background: Inhalational anesthetics were associated with reduced incidence of angiographic vasospasm and delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (SAH). Whether intravenous anesthetics provide similar level of protection is not known.

Methods: Anesthetic data were collected retrospectively for patients with SAH who received general anesthesia for aneurysm repair between January 1, 2014 and May 31, 2018, at 2 academic centers in the United States (one employing primarily inhalational and the other primarily intravenous anesthesia with propofol).

Sirtuin 1 Mediates Protection Against Delayed Cerebral Ischemia in Subarachnoid Hemorrhage in Response to Hypoxic Postconditioning.

Background Many therapies designed to prevent delayed cerebral ischemia (DCI) and improve neurological outcome in aneurysmal subarachnoid hemorrhage (SAH) have failed, likely because of targeting only one element of what has proven to be a multifactorial disease. We previously demonstrated that initiating hypoxic conditioning before SAH (hypoxic preconditioning) provides powerful protection against DCI. Here, we expanded upon these findings to determine whether hypoxic conditioning delivered at clinically relevant time points after SAH (hypoxic postconditioning) provides similarly robust DCI protection.

Return of the lesion: a meta-analysis of 1134 angiographically cured pediatric arteriovenous malformations.

Objective: Brain arteriovenous malformations (AVMs) carry a risk of rupture and subsequent morbidity or mortality unless fully treated. AVMs in pediatric patients are known to occasionally recur after obliteration. The objective of this study was to characterize the risk of AVM recurrence following angiographically confirmed obliteration in children.

Endovascular Thrombectomy Treatment: Beyond Early Time Windows and Small Core.

Tremendous advancements in the treatment of acute ischemic stroke in the last 25 years have been based on the principle of reperfusion in early time windows and identification of small core infarct for intravenous thrombolysis and mechanical thrombectomy. Advances in neuroimaging have made possible the safe treatment of patients with acute ischemic stroke in longer time windows and with more specific selection of patients with salvageable brain tissue. In this review, we discuss the history of endovascular stroke thrombectomy trials and highlight the neuroimaging-based trials that validated mechanical thrombectomy techniques in the extended time window with assessment of penumbral tissue.

Endovascular Considerations in Traumatic Injury of the Carotid and Vertebral Arteries.

Cervical carotid and vertebral artery traumatic injuries can have a devastating natural history. This article reviews the epidemiology, mechanisms of injury, clinical presentation, and classification systems pertinent to consideration of endovascular treatment. The growing role of modern endovascular techniques for the treatment of these diseases is presented to equip endovascular surgeons with a framework for critically assessing patients presenting with traumatic cervical cerebrovascular injury.