Publications by authors named "Arun Amar"

Early evidence-based medical interventions to improve patient outcomes after traumatic brain injury (TBI) are lacking. In patients admitted to the ICU after TBI, optimization of nutrition is an emerging field of interest. Specialized enteral nutrition (EN) formulas that include immunonutrition containing omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been developed and are used for their proposed anti-inflammatory and proimmune properties; however, their use has not been rigorously studied in human TBI populations.

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Background: Early evidence-based medical interventions to improve patient outcomes after traumatic brain injury (TBI) are lacking. In patients admitted to the ICU after TBI, optimization of nutrition is an emerging field of interest. Specialized enteral nutrition (EN) formulas that include immunonutrition containing omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been developed and are used for their proposed anti-inflammatory and pro-immune properties; however, their use has not been rigorously studied in human TBI populations.

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Background: Juvenile nasopharyngeal angiofibromas (JNAs) are characterized by expansive and destructive growth, often invading the midline/paranasal sinuses, pterygopalatine fossa, and infratemporal fossa and can extend into the orbit, cavernous sinus, or intracranially.

Objective: To evaluete the major benefits of the extended endoscopic endonasal approach (EEA) for JNA resection as compared with more traditional and invasive transpalatal and transfacial approaches. When JNAs extend into lateral anatomic compartments, the optimal operative trajectory often requires additional approach strategies or surgical staging.

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Background And Purpose: The treatment of complex intracranial aneurysms can be challenging with stand-alone open or endovascular techniques, particularly after rupture. A combined open and endovascular strategy can potentially limit the risk of extensive dissections with open-only techniques, and allow for aggressive definitive endovascular treatments with minimized downstream ischemic risk.

Materials And Methods: Retrospective, single-institution review of consecutive patients undergoing combined open revascularization and endovascular embolization/occlusion for complex intracranial aneurysms from 1/2016 to 6/2022.

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Acute brain injury is a leading cause of morbidity and mortality worldwide. The term is inclusive of traumatic brain injury, cerebral ischemia, subarachnoid hemorrhage, and intracerebral hemorrhage. Current pharmacologic treatments have had minimal effect on improving neurological outcomes leading to a significant interest in the development neuroprotective agents.

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Purpose: Characterizing vessel territories can provide crucial information for evaluation of cerebrovascular disorders. In this study, we present a novel postprocessing pipeline for vascular territorial imaging of cerebral arteries based on a noncontrast enhanced time-resolved 4D magnetic resonance angiography (MRA).

Methods: Eight healthy participants, 1 Moyamoya patient, and 1 arteriovenous malformations patient were recruited.

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Coronavirus disease-19 (COVID-19) pandemic continues to grow all over the world. Neurological manifestations related to COVID-19, including acute ischemic Stroke (AIS), have been reported in recent studies. In most of these, the patients are older, have multiple co-morbidities as risk factors for AIS and have developed a severe respiratory illness.

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National and regional systems of stroke care are designed to provide patients with widespread access to hospitals with thrombolytic capabilities. However, such triaging systems may contribute to fragmentation of care. This study aims to compare rates of readmission and outcomes between index and non-index hospitals for stroke patients following intravenous thrombolytic therapy (IVT).

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Objective: To investigate potential health care discrepancies in patients with ruptured cerebral aneurysms undergoing microsurgical intervention.

Methods: We retrospectively reviewed patients with ruptured intracranial aneurysms treated at our tertiary referral university hospital (UH) and safety net county hospital (CH) from 2010 to 2015. We identified 73 UH patients and 58 CH patients.

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Background: Stroke systems of care employ a hub-and-spoke model, with fewer centers performing mechanical thrombectomy (MT) compared with stroke-receiving centers, where a higher number offer high-level, centralized treatment to a large number of patients.

Objective: To characterize rates and outcomes of readmission to index and non-index hospitals for patients with ischemic stroke who underwent MT.

Methods: This study leveraged a population-based, nationally representative sample of patients with stroke undergoing MT from the Nationwide Readmissions Database between 2010 and 2014.

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Background: Aneurysmal subarachnoid hemorrhage (aSAH) requires complex multidisciplinary care. After initial treatment (index hospital), readmission to a different hospital (nonindex) can compromise quality of care, resulting in increased morbidity. We aimed to evaluate factors associated with nonindex readmission and evaluate association of nonindex hospital readmission on outcomes in patients with ruptured aneurysm.

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Purpose: Noncontrast enhanced dynamic magnetic resonance angiography delineates the pattern of dynamic blood flow of the cerebral vasculature. A model-free solution was proposed to quantify arterial blood flow (aBF) by using the monotonic property of the residual function.

Theory And Methods: Analytical simulations and in-vivo studies were performed to evaluate the performance of the proposed method by comparing the aBF values generated from the proposed and conventional singular value decomposition methods.

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Fusiform aneurysms of the vertebral artery (VA) involving the posterior inferior cerebellar artery (PICA) origin are uncommon and challenging. The anterior spinal artery (ASA) commonly originates from a unilateral ramus just distal to the PICA. Occlusion of an unpaired ASA can result in bilateral medial medullary syndrome.

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Background: Venous thromboembolism (VTE) is responsible for many hospital readmissions each year, particularly among postsurgical cohorts. Because early and indiscriminate VTE prophylaxis carries catastrophic consequences in postcraniotomy cohorts, identifying factors associated with a high risk for thromboembolic complications is important for guiding postoperative management.

Objective: To determine VTE incidence in patients undergoing nonemergent craniotomy and to evaluate for factors that predict 30-day and 90-day readmission with VTE.

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Background: A3-A3 side-to-side bypass is an intracranial-to-intracranial (IC-IC) revascularization option when aneurysm treatment involves occlusion of one anterior cerebral artery (ACA).

Objective: To describe applications of A3-A3 side-to-side bypass in the management of ACA true and pseudoaneurysms along with a review of pertinent literature.

Methods: Six consecutive patients undergoing an A3-A3 bypass as part of their aneurysm management, representing a single-surgeon experience in a 2-yr period, were included in this retrospective review of a prospectively collected database.

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Background: Successful endovascular management of aneurysmal subarachnoid hemorrhage (aSAH) requires timely access to substantial resources. Prior studies suggest an association between time to treatment and patient outcome. Patients treated at safety-net hospitals are thought to be particularly vulnerable to disparities in access to interventions that require substantial technologic resources.

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Background: Posterior inferior cerebellar artery (PICA) revascularization can be achieved with relative ease when a contralateral PICA is present. However, without a contralateral PICA, identification of a suitable vessel alternative can be challenging due to a size mismatch.

Objective: To propose the descending branch of the lateral circumflex femoral artery (DLCFA) to be an acceptable, if not preferred, arterial graft for PICA revascularization.

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Background: Clinical outcomes in the surgical management of severe traumatic brain injury (TBI) have been shown to vary across different hospital institutions. The effect of the safety-net burden on postoperative mortality, complication rates, and failure to rescue rates is unclear. We evaluated the relationship of the safety-net burden with outcomes in the treatment of patients with severe TBI undergoing neurosurgery.

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Background: Hospital readmissions are commonly linked to elevated health care costs, with significant financial incentive introduced by the Affordable Care Act to reduce readmissions.

Objective: To study the association between patient, hospital, and payer factors with national rate of readmission in acoustic neuroma surgery.

Methods: All adult inpatients undergoing surgery for acoustic neuroma in the newly introduced Nationwide Readmissions Database from 2013 to 2014 were included.

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Surgical revascularization continues to play an important role in the management of complex intracranial aneurysms and ischemic cerebrovascular disease. Graft spasm is a common complication of bypass procedures and can result in ischemia or graft thrombosis. The authors here report on the first clinical use of botulinum toxin to prevent graft spasm following extracranial-intracranial (EC-IC) bypass.

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Background: Nonsaccular vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms have high morbidity and mortality rates and are difficult to treat using standard microsurgical or endovascular techniques. Definitive revascularization can require clip trapping and/or vessel sacrifice, with PICA bypass. The published surgical experience with these approaches is limited.

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Abciximab is a glycoprotein IIb/IIIa receptor antagonist that functions to prevent platelet aggregation, thus reducing thrombus initiation and propagation. It has been widely used during percutaneous endovascular interventions, such as aneurysm coil embolization, angioplasty, atherectomy, and stent placement, as both a preventative and a salvage therapy. The use of abciximab in cardiac and neurosurgical procedures has been associated with a reduced incidence of ischemic complications and a decreased need for repeated intervention.

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In the management of acute ischemic stroke, vessel recanalization correlates with functional status, mortality, cost, and other outcome measures. Thrombolysis with intravenous tissue plasminogen activator has many limitations that restrict its applicability, but recent advances in the development of mechanical thrombectomy devices as well as improved systems of stroke care have resulted in greater likelihood of vessel revascularization. Nonetheless, there remains substantial discrepancy between rates of recanalization and rates of favorable outcome.

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Neurovascular surgery is a broad and challenging, yet exciting field within neurologic surgery. The neurovascular surgeon must be meticulous; because the brain and spinal cord are unforgiving to ischemic insults. Along with the pressures of this demanding subspecialty comes the potential to help patients recover from potentially devastating pathology to go on and lead normal, healthy lives.

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