Publications by authors named "Vamsi Gontu"

Introduction: Mechanical thrombectomy (MT) is the standard of care in anterior circulation large vessel occlusion. A vital modifiable factor is successful reperfusion. While multiple passes improve the rates of successful reperfusion, previous studies have reported progressively diminishing returns.

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Purpose: Cone-beam CT in the interventional suite could be an alternative to CT to shorten door-to-thrombectomy time. However, image quality in cone-beam CT is limited by artifacts and poor differentiation between gray and white matter. This study compared non-contrast brain dual-layer cone-beam CT in the interventional suite to reference standard CT in stroke patients.

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Article Synopsis
  • - The study compared the effectiveness and safety of four first-generation flow diverters (FDs) used for treating sidewall ICA intracranial aneurysms, which include Pipeline, Silk, FRED, and Surpass devices, using data from 444 patients across 18 institutions from 2009-2016.
  • - Analysis revealed no significant differences in retreatment rates or complications among the devices; however, the Surpass device showed the highest probability of achieving effective occlusion at follow-up, followed by FRED, Pipeline, and Silk.
  • - Although all devices had good clinical outcomes, the study highlights the need for prospective research to further clarify the differences and long-term effects of these flow diverters.
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Article Synopsis
  • Cell therapy is crucial for regenerative medicine, with macrophages playing key roles in responding to injury and recruiting other immune cells.* -
  • The study evaluated the effects of radiolabelling and catheter transport on activated macrophages during selective intra-arterial delivery to the rabbit brain, confirming cell preservation and safety.* -
  • Results showed that while activated macrophages remain suitable for this treatment, unstimulated cells are not, as they were negatively affected by the procedures.*
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Background: Mechanical thrombectomy (MT) is an effective treatment for patients with acute ischemic stroke (AIS) from basilar artery occlusion (BAO).

Objective: To compare the clinical outcomes of MT, with and without bridging intravenous thrombolysis (IVT), in acute BAO through a systematic review and meta-analysis of the current literature.

Methods: Systematic searches of Medline, EMBASE, and Cochrane Central were undertaken on August 1, 2022.

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Introduction: Identifying differences in outcome of basilar artery occlusion (BAO) between males and females may be useful in aiding clinical management. Recent studies have demonstrated widespread underrepresentation of women in acute stroke clinical trials. This international multicentre study aimed to determine sex differences in outcome after mechanical thrombectomy (MT) for patients with acute BAO.

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Purpose: The vasodilatory response to inhaled CO occurs in the acute stroke ischemic penumbra and may be a potential therapeutic modality.

Methods: Twenty-two Sprague-Dawley rats were subjected to 90-min occlusion of the M2 segment of the middle cerebral artery (M2CAO) by endovascular technique. The animals were administered different C02 concentrations and scanned serially with 9.

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Background And Purpose: Mechanical thrombectomy (MT) is an effective treatment for patients with basilar artery occlusion (BAO) acute ischemic stroke. It remains unclear whether bridging intravenous thrombolysis (IVT) prior to MT confers any benefit. This study compared the outcomes of acute BAO patients who were treated with direct MT versus combined IVT plus MT.

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Background: The use of a combination of balloon guide catheter (BGC), aspiration catheter, and stent retriever in acute ischemic stroke thrombectomy has not been shown to be better than a stent retriever and BGC alone, but this may be due to a lack of power in these studies. We therefore performed a meta-analysis on this subject.

Methods: A systematic literature search was performed on PubMed, Scopus, Embase/Ovid, and the Cochrane Library from inception to October 20, 2021.

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Background And Purpose: Dual energy CT is increasingly available and used in the standard diagnostic setting of ischemic stroke patients. We aimed to evaluate how different dual energy CT virtual monoenergetic energy levels impact identification of early ischemic changes, compared to conventional polyenergetic CT images.

Materials And Methods: This retrospective single-center study included patients presenting with acute ischemic stroke caused by an occlusion of the intracranial internal carotid artery or proximal middle cerebral artery.

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Background: Endovascular thrombectomy (ET) has transformed acute ischemic stroke (AIS) therapy in patients with large vessel occlusion (LVO). Left ventricular systolic dysfunction (LVSD) decreases global cerebral blood flow and predisposes to hypoperfusion. We evaluated the relationship between LVSD, as measured by LV ejection fraction (LVEF), and clinical outcomes in patients with anterior cerebral circulation LVO who underwent ET.

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Background: Collateral blood flow is known to be an important factor that sustains the penumbra during acute stroke. We looked at both the leptomeningeal collateral circulation and the presence of anterior and posterior communicating arteries to determine the factors associated with good outcomes and mortality.

Methods: We included all patients with acute ischaemic stroke in the anterior circulation, who underwent thrombectomy with the same thrombectomy device from 2013 to 2016.

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Background: Studies have shown that the modified thrombolysis in cerebral ischemia (mTICI) 2B score is associated with better functional outcome; however, 50-99% reperfusion is a large range and there may be factors which can differentiate this further. The effects of very late leptomeningeal collaterals (VLLC) on mTICI-2B patients were studied.

Method: A prospectively collected registry of anterior circulation AIS patients treated with the EmboTrap revascularization device from 2013 to 2016 was evaluated.

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Background: We studied patients treated with the EmboTrap revascularization device in a prospective registry which is core laboratory evaluated by physicians from external centers. The goal was to determine how the EmboTrap would perform under the everyday conditions of a high-volume stroke center.

Methods: We examined all patients with acute stroke treated with the Embotrap device from October 2013 to March 2017 in our center.

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Background: Distal embolization or movement of the thrombus to previously uninvolved vasculature are feared complications during stroke thrombectomy. We looked at associated factors in a consecutive series of patients who underwent thrombectomy with the same endovascular device.

Methods: We included all patients with acute ischemic stroke in the anterior or posterior circulation, who underwent thrombectomy with the same thrombectomy device for acute stroke from 2013 to 2016.

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Background Emergency stent placement in the extracranial internal carotid artery in combination with anterior circulation thrombectomy is a routine procedure. Yet, precise indications and clinical safety in this setting remains controversial. Present data for mechanical thrombectomy include few studies with acute stenting of tandem occlusions.

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The arterial blood supply to the dura mater is rich, complex and is derived from both the internal and external carotid systems. Endovascular management of a variety of intracranial diseases necessitates a thorough understanding of the dural arterial network. In this article we review the normal contributions of the pial arteries to the blood supply of the dura mater and discuss some aspects of its role in the supply of dural arteriovenous shunts (DAVS).

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Unfused basilar arteries, frequently but erroneously referred to as 'fenestrations', are not uncommonly associated with aneurysms. The difficulty in treating these aneurysms lie in the fact that they are often wide necked and frequently incorporate both channels of the unfused segment, with varying calibres of the channels, necessitating technically challenging treatment strategies. It is important to preserve both channels because of the potential presence of perforating arteries originating from these segments.

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Magnetic resonance angiography (MRA) is commonly used to follow up patients after endovascular treatment for intracranial aneurysms. Magnetic resonance artefacts from coil constructs may impair image quality and jeopardise the evaluation of the effectiveness of treatment and review of adjacent vasculature. We present here a technical note on the usage of Barricade coils recently introduced at our institution.

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There is increasing interest in developing a reliable, affordable and accessible disease biomarker of Parkinson's disease (PD) to facilitate disease modifying PD-trials. Imaging biomarkers using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) can describe parameters such as fractional anisotropy (FA), mean diffusivity (MD) or apparent diffusion coefficient (ADC). These parameters, when measured in the substantia nigra (SN), have not only shown promising but also varying and controversial results.

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Depigmentation of the substantia nigra is a conspicuous pathological feature of Parkinson's disease and related to a loss of neuromelanin. Similar to melanin, neuromelanin has paramagnetic properties resulting in signal increase on specific T1-weighted magnetic resonance imaging. The aim of this study was to assess signal changes in the substantia nigra in patients with Parkinson's disease using an optimized neuromelanin-sensitive T1 scan.

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Background: Previous studies have compared the accuracy of spiral analysis in distinguishing essential tremor (ET) from PD. In this study, we have used this technique to distinguish cases of tremulous PD (TDPD) (N = 24) from tremulous parkinsonian subjects without evidence of dopaminergic deficit (N = 41).

Methods: All patients were characterized on clinical and (123)I-N-ω-fluoro-propyl-2ß-carbomethoxy-3ß-(4-iodophenyl) nortropane ([(123)I] FP-CIT) SPECT scan data, which were concordant in every case.

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Background: This study examines the clinical accuracy of movement disorder specialists in distinguishing tremor dominant Parkinson's disease (TDPD) from other tremulous movement disorders by the use of standardised patient videos.

Patients And Methods: Two movement disorder specialists were asked to distinguish TDPD from patients with atypical tremor and dystonic tremor, who had no evidence of presynaptic dopaminergic deficit (subjects without evidence of dopaminergic deficit (SWEDDs)) according to (123)I-N-ω-fluoro-propyl- 2β-carbomethoxy-3β-(4-iodophenyl) nortropane ([(123)I] FP-CIT) single photon emission computed tomography (SPECT), by 'blinded' video analysis in 38 patients. A diagnosis of parkinsonism was made if the step 1 criteria of the Queen Square Brain Bank criteria for Parkinson's disease were fulfilled.

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