Increased Success of Single-Pass Large Vessel Recanalization Using a Combined Stentriever and Aspiration Technique: A Single Institution Study.

BACKGROUND: Extensive evidence supports mechanical thrombectomy using stentrievers (SR) for acute large vessel occlusion (aLVO). Aspiration is also used as a first pass or adjunct technique during clot removal. Here we report technical results from mechanical thrombectomy cases using SR alone, aspiration alone (AD), or a combination of SR and aspiration (SA) as a first pass for aLVO. METHODS: An institutional stroke database was reviewed for patients presenting to a single academic institution with anterior circulation aLVO and who were treated with mechanical thrombectomy from 2011 to 2017. Patients managed with SR alone, AD, or a combination of these 2 techniques (SA) were identified. The rate of successful recanalization after the first thrombectomy attempt was compared between the 3 groups. RESULTS: A total of 353 patients were analyzed, including 215 in SR, 32 in AD, and 106 in SA groups. There was no significant difference for age and admission National Institutes of Health Stroke Scale between the groups. Successful recanalization rates after the first pass were 35.8% in the SR group, 34.4% in aspiration as a first pass technique, and 55.7% in SA, with a statistically significant higher rate of first pass success in the SA group (P = 0.002). Using balloon-guide catheter doubled the rate of successful first pass recanalization from 21.3% to 41.6% in the SR group (P = 0.005); however, the SA technique was more effective for first pass recanalization when compared with an SR and balloon-guide catheter combination (55.7% vs. 41.6%, P = 0.025). CONCLUSIONS: The combination of SR and catheter aspiration can increase the rate of single pass successful recanalization compared with these techniques individually.

Age-related changes in dentate gyrus cell numbers, neurogenesis, and associations with cognitive impairments in the rhesus monkey.

The generation of new neurons in the adult mammalian brain is well-established for the hippocampal dentate gyrus (DG). However, the role of neurogenesis in hippocampal function and cognition, how it changes in aging, and the mechanisms underlying this are yet to be elucidated in the monkey brain. To address this, we investigated adult neurogenesis in the DG of 42 rhesus monkeys (39 cognitively tested) ranging in age from young adult to the elderly. We report here that there is an age-related decline in proliferation and a delayed development of adult neuronal phenotype. Additionally, we show that many of the new neurons survive throughout the lifetime of the animal and may contribute to a modest increase in total neuron number in the granule cell layer of the DG over the adult life span. Lastly, we find that measures of decreased adult neurogenesis are only modestly predictive of age-related cognitive impairment.

High-flow carotid cavernous fistula and the use of a microvascular plug system: initial experience.

PURPOSE: We report our initial experience using a detachable microvascular plug system to occlude the internal carotid artery during endovascular treatment of high-flow carotid cavernous fistula. CASE AND TECHNIQUE: An 87-year-old patient was admitted for acute-onset double vision with associated right-eye ptosis. Exam revealed a pupil-sparing, partial right third cranial nerve palsy. MRI showed a carotid cavernous fistula with high-flow drainage. Digital subtraction angiography showed a high-flow, right-sided, direct carotid cavernous fistula with flow from the proximal right internal carotid artery. The ophthalmic artery, posterior communicating artery and anterior communicating arteries supplied retrograde flow to the fistula through the internal carotid artery. Obliteration of the fistula was achieved through coil embolization in combination with proximal and distal microvascular plugs (Reverse Medical, Irvine, Calif., USA). CONCLUSION: The microvascular plug is a new addition to current endovascular embolization devices for the treatment of high-flow, direct carotid cavernous fistulas. This technique offers easy navigability through tortuous arteries, precise localization and immediate occlusion, which may allow shorter procedure and fluoroscopy times and increased cost-effectiveness. Larger case series are needed to support our observation.

Expression of hypoxia-inducible factor-1 and vascular endothelial growth factor in response to venous hypertension.

OBJECTIVE: Experimentally, a fistula created surgically between the carotid artery and jugular vein, together with occlusion of venous sinuses, generate venous hypertension, which can induce dural arteriovenous fistula formation intracranially in rats. Our aim was to study the effect of nonischemic venous hypertension on the elaboration of the angiogenic signal, hypoxia-inducible factor-1 (HIF-1), and its downstream signal, vascular endothelial growth factor (VEGF). METHODS: Sixty rats were exposed to venous hypertension for periods ranging from 4 hours to 3 weeks. Western blot analysis, transbinding assays, enzyme-linked immunosorbent assays, and immunohistochemistry quantified HIF-1 and VEGF expression in brain. Forty-eight control rats underwent similar surgical procedures without creating venous hypertension. Cerebral blood flow was measured at baseline, after surgery, and before sacrifice. RESULTS: Venous hypertension did not impair cerebral blood flow. Relative to controls, HIF-1 expression increased fivefold in response to venous hypertension (P < 0.005), with peak expression 1 day later localized to endothelial cells in venules next to the sagittal sinus. VEGF expression also increased threefold in response to venous hypertension (P < 0.05), with peak expression 7 days later localized to parasagittal astrocytes. HIF-1 and VEGF were minimally expressed in rat normal venous pressures. CONCLUSION: In this model, venous hypertension stimulates angiogenesis by a mechanism other than ischemia. HIF-1 expression may result from dilation of parasagittal veins and endothelial deformation. HIF-1 and VEGF seem to be molecular agents that convert venous hypertension into intracellular signals and angiogenesis activity.