Citations

Abstract Embolic protection devices (EPDs) have become a standard of care during internal carotid artery revascularization. 1,2 This video is about a 57-yr-old-male who presented with a wake-up stroke with a left hemispheric syndrome. Head computed tomography angiography (CTA) revealed tandem occlusions of the proximal left internal carotid artery (ICA) and of the distal left middle cerebral artery (MCA) with an ASPECT (Alberta Stroke Program Early CT Score) score of 6. The patient underwent a cerebral angiogram and was treated with balloon angioplasty with a distal EPD and mechanical thrombectomy. The EPD became occluded with thrombus from the ICA and was retrieved through a 6-Fr Sofia (MicroVention) under continuous aspiration. Successful revascularization of the proximal ICA and distal MCA was achieved. No procedure-related complications occurred, and the patient's neurological exam improved. Tandem occlusions can occur in up to 15% of strokes. The optimal treatment can be controversial, but mechanical thrombectomy and ICA revascularization with a distal EPD appear to be safe and effective in selected patients. 3 Consent was obtained for the procedure and for the video production.

AbstractFibrin is a degradable biopolymer with an excellent clinical safety profile. Use of higher mechanical strength fibrin hydrogels is limited by the rapid rate of fibrin polymerization. We recently demonstrated the use of higher mechanical strength (fibrinogen concentrations >30 mg/ml) fibrin scaffolds for surgical implantation of cells. The rapid polymerization of fibrin at fibrinogen concentrations impaired our ability to scale production of these fibrin scaffolds. We serendipitously discovered that the azo dye Trypan blue (TB) slowed fibrin gelation kinetics allowing for more uniform mixing of fibrinogen and thrombin at high concentrations. A screen of closely related compounds identified similar activity for Evans blue (EB), an isomer of TB. Both TB and EB exhibited a concentration dependent increase in clot time, though EB had a larger effect. While gelation time was increased by TB or EB, overall polymerization time was unaffected. Scanning electron microscopy showed similar surface topography, but transmission electron microscopy showed a higher cross‐linking density for gels formed with TB or EB versus controls. Based on these data we conclude that addition of TB or EB during thrombin mediated fibrin polymerization slows the initial gelation time permitting generation of larger more uniform fibrin hydrogels with high‐mechanical strength.

Abstract Intracranial atherosclerotic disease (ICAD) is a common cause of stroke. Antiplatelet therapy is the mainstay for symptomatic ICAD treatment. Endovascular management with submaximal angioplasty and/or intracranial stenting is reserved for patients with repeated ischemic events despite optimal medical therapy. We demonstrate intracranial angioplasty and stenting technique, technique indications, and sizing of stent and target vessel diameter. Stenting and angioplasty have been described in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis and Wingspan Stent System Post Market Surveillance trials. 1,2 Submaximal angioplasty has also been described. 3 This patient, who had been on dual antiplatelet therapy for several months, initially presented with occlusion of the left middle cerebral artery M2 inferior division and underwent mechanical thrombectomy with successful reperfusion. Postoperatively, the patient's symptoms did not improve. Medical management was optimized with heparin infusion. However, repeat stroke study demonstrated M2 inferior division reocclusion. A decision was made to proceed with intracranial angioplasty and stenting. P2Y12 levels were therapeutic. Under moderate conscious sedation, submaximal angioplasty of up to 80% of the normal M2 caliber was attempted. However, we observed persistent high-grade stenosis of the M2 inferior division. The major risk of crossing the lesion for angioplasty is vessel perforation. To safely perform this maneuver, we used a J-configured Synchro-2 microwire (Stryker). Because of the patient's recent thrombectomy, we also had prior tactile feedback about how much resistance was encountered while crossing the occlusion. We then deployed a balloon-mounted intracranial stent for optimal radial force across the stenotic area to restore perfusion. Postoperative computed tomography perfusion showed resolution of the previously noticed perfusion deficit. The patient gave informed consent for the procedures and video recording. Institutional review board approval was deemed unnecessary. Video. ©University at Buffalo Neurosurgery, September 2020. With permission.

Abstract INTRODUCTION: Retinal imaging is a non-invasive tool to study retinal vasculature and neurodegeneration. Patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD)-related cognitive disorder exhibit both retinal vascular abnormalities and intraretinal accumulation of amyloid beta-protein (Aβ) plaque. Curcumin-enhanced retinal fluorescence imaging (CRFI) was recently translated as a safe imaging tool for retinal Aβ plaque quantification, holding promise as an early-stage pathological biomarker of AD. In this exploratory study, we sought to determine whether retinal vascular features combined with retinal amyloid burden correlate with the neurocognitive status.METHODS: We used scanning laser ophthalmoscopy to assess quantitative CRFI in a cohort of patients with cognitive impairment that underwent standard neuropsychological testing. Retinal blood vessels were segmented in a predefined circumpapillary region of interest. For each centerline, vessel tortuosity index, vessel inflection index and branching angle was quantified. Additionally, we automatically quantified retinal amyloid count in the supero-temporal quadrant and its subregions: posterior pole, proximal mid-periphery, and distal mid-periphery. Investigators performing quantifications were blinded to the subjects’ clinical characteristics. Linear regression models were used to assess the correlations between retinal vascular and amyloid parameters and cognitive domain Z-scores.RESULTS: In this pilot study, 34 subjects underwent automated retinal amyloid imaging and 29 subjects (55% female, mean age 64±6 years) had the combined retinal amyloid and peripapillary vascular analysis. Eleven subjects had normal cognition, 15 MCI, 2 probable AD and 1 non-AD dementia. CRFI was increased in individuals with impaired versus normal cognitive function (p 0.0012). Venous VTI was the most significant vascular parameter that differ across levels of CDR. Branching angle correlated with amyloid count in the distal mid-periphery (p=0.03), whereas vessel inflexion index correlated with posterior pole amyloid count (p=0.02). The combined proximal mid-periphery amyloid count – venous tortuosity index was found to exhibit highly significant group differences between cognitively impaired and cognitively normal subjects (0.49 ± 1.1 vs 0.91 ± 1.4, p=0.006). The combined proximal mid-periphery amyloid-venous tortuosity index also correlated with verbal memory (Wechsler Memory Scale-IV; p=0.001) and cognitive-related quality of life (SF-36 mental component score Z-scores; p=0.039).CONCLUSION: Retinal venular tortuosity discriminates across cognitive scores and in combination with proximal mid-periphery amyloid count predicts verbal memory and cognitive-related quality-of-life. Future research is needed to confirm the clinical utility of this integrated retinal imaging-based methodology.

Abstract Vascular access for cerebral angiography has traditionally been performed via the common femoral artery. It is crucial to obtain safe access to prevent complications that could lead to limb ischemia, groin hematoma, or retroperitoneal hematoma. This is especially true in neurointervention as many patients are anticoagulated or have received intravenous thrombolytics prior to their intervention. Special attention to anatomic landmarks, both grossly and radiographically, can help to assure safe access. The patient consented for this procedure. This video details rapid but safe femoral artery access in a patient undergoing emergent thrombectomy.

Abstract Management options for carotid stenosis include medical management, carotid endarterectomy, carotid stenting with distal filter protection, or stenting with either flow arrest or flow reversal techniques. 1 Flow reversal with transcarotid artery revascularization (TCAR) technique represents a hybrid approach with surgical access to the common carotid for endovascular placement of a stent in the internal carotid artery. This direct access to the carotid artery avoids navigating the challenging anatomy of the aortic arch with endovascular devices. 2 Compared to transfemoral stenting, TCAR possesses lower risk of transient ischemic attack and stroke, and compared to carotid endarterectomy, there is less risk of cranial neuropathy. 3,4 We present the case of an 87-yr-old man with recurrent severe stenosis (85%) of the right internal carotid artery. The patient had a remote history of bilateral endarterectomies for asymptomatic stenosis and was found with recurrence and progression of right internal carotid artery stenosis. Options were discussed and decision was made to proceed with TCAR after he consented for the procedure. The patient tolerated the procedure well with satisfactory revascularization. Exam remained unremarkable prior to discharge on postoperative day 1 and during follow-up at 1 mo. Patient consented to the publication of their image.

Spinal cord injury (SCI) results in cell death, demyelination, and axonal loss. The spinal cord has a limited ability to regenerate, and current clinical therapies for SCI are not effective in helping promote neurologic recovery. We have developed a novel scaffold biomaterial that is fabricated from the biodegradable hydrogel oligo(poly(ethylene glycol)fumarate) (OPF). We have previously shown that positively charged OPF scaffolds (OPF+) in an open spaced, multichannel design can be loaded with Schwann cells to support axonal generation and functional recovery following SCI. We have now developed a hybrid OPF+ biomaterial that increases the surface area available for cell attachment and that contains an aligned microarchitecture and extracellular matrix (ECM) proteins to better support axonal regeneration. OPF+ was fabricated as 0.08 mm thick sheets containing 100 μm high polymer ridges that self-assemble into a spiral shape when hydrated. Laminin, fibronectin, or collagen I coating promoted neuron attachment and axonal outgrowth on the scaffold surface. In addition, the ridges aligned axons in a longitudinal bipolar orientation. Decreasing the space between the ridges increased the number of cells and neurites aligned in the direction of the ridge. Schwann cells seeded on laminin coated OPF+ sheets aligned along the ridges over a 6-day period and could myelinate dorsal root ganglion neurons over 4 weeks. This novel scaffold design, with closer spaced ridges and Schwann cells, is a novel biomaterial construct to promote regeneration after SCI.

The mammalian cell nucleus consists of numerous compartments involved in the regular unfolding of processes such as DNA replication and transcription, RNA maturation, protein synthesis and cell division. Knowledge is increasing of the relationships between high-order levels of chromatin organization and its spatial organization, and of how these relationships contribute to the various functions carried out in the nucleus. We have studied the spatial arrangement of mouse telocentric chromosomes 5, 11, 13, 15, 16 and 17, some of their metacentric Robertsonian derivatives, and X and Y chromosomes by whole chromosome painting in male germ (spermatogonia, pachytene spermatocytes and spermatids) and Sertoli cells of homozygous and heterozygous individuals. Using dual-colour fluorescence in situ hybridization we found that these chromosomes occupy specific nuclear territories in each cell type analysed. When chromosomes are present as Robertsonian metacentrics in the heterozygous state, that is, as Robertsonian metacentrics and their homologous telocentrics, differences in their nuclear positions are detectable: heterozygosity regularly produces a change in the nuclear position of one of the two homologous telocentrics in all the cell types studied. In the Robertsonian heterozygotes, the vast majority of the Sertoli cells show the sex chromosomes in a condensed state, whereas they appear decondensed in the Robertsonian homozygotes. As the Robertsonian heterozygosities we studied produce a chromosomally derived impairment of male germ-cell differentiation, we discuss the possibility that changes in chromosome spatial territories may alter some nuclear machinery (e.g., synapsis, differential gene expression) important for the correct unfolding of the meiotic process and for the proper functioning of Sertoli cells.

Abstract Cerebral venous sinus stenting has gained popularity in recent years as a safe and efficacious treatment of selected patients with idiopathic intracranial hypertension (IIH) and focal venous sinus stenosis.1–3 - 3 The main goal of treatment is to prevent visual loss, and often patients report resolution of headache and visual symptoms within 21 mo of mean follow-up.4–8 - 8 We present the case of a 57-yr-old woman with medically refractory IIH, bilateral sinus stenosis, and a mass lesion causing stenosis on the left. Venous angiogram with pressure monitoring was completed with the patient awake, which showed a significant pressure gradient on the right (19 mm Hg) and borderline gradient on the left (8 mm Hg). Options were reviewed and decision was made to proceed with the treatment of the right-sided stenosis with stenting and continue with the observation of the lesion on the left to prevent further visual deterioration. The patient consented for the procedure, and she tolerated the procedure well. Neurological exam remained at baseline, and she was discharged home on post-operative day #1. At 2 mo’s follow-up, the patient reported improvement in headaches and remained intact neurologically.