Use of a dedicated open transcarotid access system for neurovascular disease.

BACKGROUND: Transcarotid artery revascularization (TCAR) is an increasingly popular technique for the management of extracranial carotid stenosis. Its off-label use in the treatment of intracranial neurovascular disease is poorly described. Our objective is to describe the use of a dedicated open transcarotid access system for the treatment of neurovascular pathologies other than extracranial carotid stenosis. METHODS: We conducted a retrospective review of a prospectively maintained database of consecutive patients who underwent treatment of neurovascular disease at a single academic center using the ENROUTE Transcarotid Arterial Sheath. Demographics, procedural characteristics, and patient outcomes were reported. RESULTS: Twenty patients were included in the study between September 2017 and March 2023. The following pathologies were treated: intracranial atherosclerotic disease (ICAD, nine patients), complex cervico-petrous carotid disease (five patients), intracranial aneurysms (three patients), and large vessel occlusion-acute ischemic stroke (three patients). Eighteen of the 20 cases were performed with active carotid flow reversal. All cases were successfully completed. There were no access-related complications. One periprocedural complication was incurred: a microguidewire perforation during an exchange maneuver for the treatment of ICAD. CONCLUSION: An open transcarotid approach using a dedicated transcarotid system may offer a safe alternative access strategy for the endovascular treatment of complex neurovascular pathologies when a traditional transfemoral or transradial approach is contraindicated or failed.

Robotic Diagnostic Cerebral Angiography: A Multicenter Experience of 113 Patients.

BACKGROUND: Neurointerventional robotic systems have potential to reduce occupational radiation, improve procedural precision, and allow for future remote teleoperation. A limited number of single institution case reports and series have been published outlining the safety and feasibility of robot-assisted diagnostic cerebral angiography. METHODS: This is a multicenter, retrospective case series of patients undergoing diagnostic cerebral angiography at three separate institutions - University of California, Davis (UCD); University of California, Los Angeles (UCLA); and University of California, San Francisco (UCSF). The equipment used was the CorPath GRX Robotic System (Corindus, Waltham, MA). RESULTS: A total of 113 cases were analyzed who underwent robot-assisted diagnostic cerebral angiography from September 28, 2020 to October 27, 2022. There were no significant complications related to use of the robotic system including stroke, arterial dissection, bleeding, or pseudoaneurysm formation at the access site. Using the robotic system, 88 of 113 (77.9%) cases were completed successfully without unplanned manual conversion. The principal causes for unplanned manual conversion included challenging anatomy, technical difficulty with the bedside robotic cassette, and hubbing out of the robotic system due to limited working length. For robotic operation, average fluoroscopy time was 13.2 min (interquartile range (IQR), 9.3 to 16.8 min) and average cumulative air kerma was 975.8 mGY (IQR, 350.8 to 1073.5 mGy). CONCLUSIONS: Robotic cerebral angiography with the CorPath GRX Robotic System is safe and easily learned by novice users without much prior manual experience. However, there are technical limitations such as a short working length and an inability to support 0.035" wires which may limit its widespread adoption in clinical practice.

Transcarotid artery revascularization (TCAR): a technical video.

Carotid revascularization is an important method of stroke prevention and includes carotid endarterectomy and transfemoral carotid angioplasty and stenting. More recently, a hybrid open-endovascular approach, termed transcarotid artery revascularization (TCAR), is garnering increased attention. Although fundamentally a 'stenting procedure', unlike transfemoral carotid angioplasty and stenting, TCAR allows for a proximal neuroprotection strategy based on flow reversal. In this technical video, we will review operative techniques and nuances of the TCAR procedure, with a particular focus on the neurovascular proceduralist looking to adopt this technique into routine clinical practice(video 1). neurintsurg;14/8/842/V1F1V1Video 1TCAR Technical Video.

Patient Risk Factors Associated With 30- and 90-Day Readmission After Ventriculoperitoneal Shunt Placement for Idiopathic Normal Pressure Hydrocephalus in Elderly Patients: A Nationwide Readmission Study.

OBJECTIVE: For idiopathic normal pressure hydrocephalus (iNPH), risk stratifying patients and identifying those who are likely to fare well after ventriculoperitoneal shunt (VP) surgery may help improve quality of care and reduce unplanned readmissions. The aim of this study was to investigate the drivers of 30- and 90-day readmissions after VP shunt surgery for iNPH in elderly patients. METHODS: The Nationwide Readmission Database, years 2013 to 2015, was queried. Elderly patients (≥65 years old) undergoing VP shunt surgery were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Unique patient linkage numbers were used to follow patients and identify 30- and 31- to 90-day readmission rates. Patients were grouped by no readmission (Non-R), readmission within 30 days (30-R), and readmission within 31 to 90 days (90-R). RESULTS: We identified 7199 elderly patients undergoing VP shunt surgery for iNPH. A total of 1413 (19.6%) patients were readmitted (30-R: n = 812 [11.3%] vs. 90-R: n = 601 [8.3%] vs. Non-R: n = 5786). The most prevalent 30- and 90-day complications seen among the readmitted cohort were mechanical complication of nervous system device implant (30-R: 16.1%, 90-R: 12.4%), extracranial postoperative infection (30-R: 10.4%, 90-R: 7.0%), and subdural hemorrhage (30-R: 6.0%, 90-R: 16.4%). On multivariate regression analysis, age, diabetes, and renal failure were independently associated with 30-day readmission; female sex, and 26th to 50th household income percentile were independently associated with reduced likelihood of 90-day readmission. Having any complication during the index admission independently associated with both 30- and 90-day readmission. CONCLUSIONS: In this study, we identify the most common drivers for readmission for elderly patients with iNPH undergoing VP shunt surgery.

Neuronal Rac1 is required for learning-evoked neurogenesis.

Hippocampus-dependent learning and memory relies on synaptic plasticity as well as network adaptations provided by the addition of adult-born neurons. We have previously shown that activity-induced intracellular signaling through the Rho family small GTPase Rac1 is necessary in forebrain projection neurons for normal synaptic plasticity in vivo, and here we show that selective loss of neuronal Rac1 also impairs the learning-evoked increase in neurogenesis in the adult mouse hippocampus. Earlier work has indicated that experience elevates the abundance of adult-born neurons in the hippocampus primarily by enhancing the survival of neurons produced just before the learning event. Loss of Rac1 in mature projection neurons did reduce learning-evoked neurogenesis but, contrary to our expectations, these effects were not mediated by altering the survival of young neurons in the hippocampus. Instead, loss of neuronal Rac1 activation selectively impaired a learning-evoked increase in the proliferation and accumulation of neural precursors generated during the learning event itself. This indicates that experience-induced alterations in neurogenesis can be mechanistically resolved into two effects: (1) the well documented but Rac1-independent signaling cascade that enhances the survival of young postmitotic neurons; and (2) a previously unrecognized Rac1-dependent signaling cascade that stimulates the proliferative production and retention of new neurons generated during learning itself.

Absence of CCL2 is sufficient to restore hippocampal neurogenesis following cranial irradiation.

Cranial irradiation for the treatment of brain tumors causes a delayed and progressive cognitive decline that is pronounced in young patients. Dysregulation of neural stem and progenitor cells is thought to contribute to these effects by altering early childhood brain development. Earlier work has shown that irradiation creates a chronic neuroinflammatory state that severely and selectively impairs postnatal and adult neurogenesis. Here we show that irradiation induces a transient non-classical cytokine response with selective upregulation of CCL2/monocyte chemoattractant protein-1 (MCP-1). Absence of CCL2 signaling in the hours after irradiation is alone sufficient to attenuate chronic microglia activation and allow the recovery of neurogenesis in the weeks following irradiation. This identifies CCL2 signaling as a potential clinical target for moderating the long-term defects in neural stem cell function following cranial radiation in children.

Characterization of axon guidance cue sensitivity of human embryonic stem cell-derived dopaminergic neurons.

Dopaminergic neurons derived from human embryonic stem cells will be useful in future transplantation studies of Parkinson's disease patients. As newly generated neurons must integrate and reconnect with host cells, the ability of hESC-derived neurons to respond to axon guidance cues will be critical. Both Netrin-1 and Slit-2 guide rodent embryonic dopaminergic (DA) neurons in vitro and in vivo, but very little is known about the response of hESC-derived DA neurons to any axonal guidance cues. Here we examined the ability of Netrin-1 and Slit-2 to affect human ESC DA axons in vitro. hESC DA neurons mature over time in culture with the developmental profile of DA neurons in vivo, including expression of the DA neuron markers FoxA2, En-1 and Nurr-1, and receptors for both Netrin and Slit. hESC DA neurons respond to exogenous Netrin-1 and Slit-2, showing an increased responsiveness to Netrin-1 as the neurons mature in culture. These responses were maintained in the presence of pro-inflammatory cytokines that might be encountered in the diseased brain. These studies are the first to evaluate and confirm that suitably matured human ES-derived DA neurons can respond appropriately to axon guidance cues.