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Papers by Guilherme Dabus

Research paper thumbnail of Cerebrovascular Anatomy Part II

Research paper thumbnail of SNIS Programming: Coils, Pipes and Webs: State of the Art Treatment - An Update on Embolization Treatment of Dural AVF and AVM

Research paper thumbnail of Carotid and Subclavian Stenting Workshop

Research paper thumbnail of Vertebral Artery Stenosis: when and how to treat

Research paper thumbnail of Stroke: Imaging and Intervention

Research paper thumbnail of Wake Up Call: Vascular Malformations

Research paper thumbnail of Dangerous Arterial Connections In The Head And Neck: Avoiding Neurological Complications

Research paper thumbnail of Intracranial Stenting in Acute Stroke

Research paper thumbnail of Cranio-Facial Vascular Anomalies: Update on Diagnosis and Interventional Management

Research paper thumbnail of Stroke Set Up and Workflow

Research paper thumbnail of Newer Generation Hydrogel Coils: Clinical Experience with Hydrosoft Helical and 3D

Research paper thumbnail of Stroke Intervention: From Basics to Advanced

Research paper thumbnail of Dural Arteriovenous Fistula

Research paper thumbnail of Off-label Use of Flow Diverters

Research paper thumbnail of Acute ischemic stroke. Introduction

Techniques in vascular and interventional radiology, 2012

Research paper thumbnail of Interaction between time to treatment and reperfusion therapy in patients with acute ischemic stroke

Journal of NeuroInterventional Surgery, 2013

‘Time is brain’ is a slogan that has been used by stroke advocacy groups to raise public awarenes... more ‘Time is brain’ is a slogan that has been used by stroke advocacy groups to raise public awareness that stroke is a medical emergency which requires timely treatment.1 Similarly, the acronym FAST (face, arm, speech, time) has been advertised as an easy way to remember the most common stroke symptoms and the need to act quickly.2 The time dependent nature of brain injury following an ischemic event has been characterized in animal experiments. Early studies have shown that brain tissue gradually undergoes irreversible damage following an acute ischemic stroke. These studies suggest that infarct growth can be described by a logarithmic or a sigmoidal function. The rate at which tissue transitions from reversible to irreversible injury is dependent on the depth of the ischemia; with mild reductions in cerebral blood flow, brain tissue remains viable for a relatively long duration, whereas cerebral injury becomes irreversible rapidly when cerebral blood flow is severely impaired (figure 1).3 ,4 Another factor that determines the rate at which tissue undergoes irreversible ischemic injury is the type of tissue that is involved. For example, gray matter, which has a higher metabolic demand, is more susceptible to ischemia than white matter.5 The average rate of neuronal loss in humans is estimated to be 1.9 million neurons per minute during the first 10 h after stroke onset.1 These data indicate that stroke treatments aimed at restoring blood flow are most effective when they are initiated early. Figure 1 Schematic representation of infarct volume evolution. A schematic representation of the evolution of infarct volume is shown for three hypothetical scenarios: the patient with a severe reduction in cerebral blood flow (CBF) (purple line) experiences rapid expansion of the infarct, which reaches its final volume early; moderate growth is seen in the patient with a …

Research paper thumbnail of Valor preditivo da distensão de alças intestinais em radiografias no prognóstico de enterocolite necrosante

Radiologia Brasileira, 2007

OBJETIVO: Avaliar o valor prognóstico da distensão de alças intestinais observada em radiografias... more OBJETIVO: Avaliar o valor prognóstico da distensão de alças intestinais observada em radiografias na evolução e mortalidade de neonatos com enterocolite necrosante. MATERIAIS E MÉTODOS: Nas radiografias de abdome de 53 pacientes obtidas no momento da suspeita diagnóstica de enterocolite necrosante, foi realizada a medida do diâmetro da alça mais distendida (AD), assim como a distância entre a borda superior da primeira vértebra lombar e a borda inferior da segunda (L1-L2), a distância entre as bordas laterais dos pedículos da primeira vértebra lombar (L1), e foram estabelecidas as associações entre AD/L1-L2 e AD/L1. Esta medida foi considerada como possível determinante de potenciais complicações, intervenção cirúrgica e mortalidade. RESULTADOS: Os pacientes que necessitaram de tratamento cirúrgico, aqueles que tiveram complicações durante a evolução e aqueles que morreram da doença tiveram a relação entre AD e AD/L1-L2 maiores (p < 0,05). Os valores de AD/L1 e a localização da a...

Research paper thumbnail of Percutaneous cholecystostomy: a nonsurgical therapeutic option for acute cholecystitis in high-risk and critically ill patients

Sao Paulo Medical Journal, 2003

Percutaneous cholecystostomy offers a potentially important type of therapy for critically ill pa... more Percutaneous cholecystostomy offers a potentially important type of therapy for critically ill patients with acute cholecystitis who present high risk when undergoing laparotomy or laparoscopy under general anesthesia. It offers a distinct advantage for these kinds of patients by avoiding the risks of the surgical intervention. Percutaneous cholecystostomy is a safe and effective minimally invasive procedure with a high success rate and low procedure-related complications. It should be considered not only in temporary management of calculous cholecystitis, but also in definitive treatment in cases of acalculous cholecystitis.

Research paper thumbnail of Extrarenal Wilms' tumor—A case report

Journal of Pediatric Surgery, 1988

The authors present a literature review on pulmonary embolism and conclude that pulmonary embolec... more The authors present a literature review on pulmonary embolism and conclude that pulmonary embolectomy is indicated in patients in whom thrombolytic therapy is contraindicated, or in those who are so compromised that a trial of medical management is not warranted and in those deteriorating on thrombolytic therapy. They state that patients with acute massive pulmonary emboli should be transferred to a center with full cardiopulmonary bypass capabilities.

Research paper thumbnail of MRI findings in the diagnosis and monitoring of rasmussen's encephalitis

Arquivos de Neuro-Psiquiatria, 2009

Rasmussen's encephalitis is a devastating syndrome of multifocal brain dysfunction and focal ... more Rasmussen's encephalitis is a devastating syndrome of multifocal brain dysfunction and focal seizures. Magnetic resonance (MR) findings, associated with clinical data and electroencephalogram (EEG), may indicate the diagnosis and could be an indicative of prognosis. We studied 5 patients with Rasmussen's encephalitis, assessing clinical history and MR images. All patients had refractory focal seizures with a predominant motor component associated with hemispheric atrophy, that was proportional to severity of disease and neurological deficits in these patients. Gray and white matter abnormal signal on T2 MR images were found in patients who had hemiparesis. It was not related to the duration of the disease but to aggressiveness. MR proton spectroscopy in severe disease showed lactate and choline increase and decreased NAA, reflecting neuronal and axonal loss, gliosis and elevated membrane turnover and recent - crisis (not controlled). MR studies, in addition to help in diagno...

Research paper thumbnail of Cerebrovascular Anatomy Part II

Research paper thumbnail of SNIS Programming: Coils, Pipes and Webs: State of the Art Treatment - An Update on Embolization Treatment of Dural AVF and AVM

Research paper thumbnail of Carotid and Subclavian Stenting Workshop

Research paper thumbnail of Vertebral Artery Stenosis: when and how to treat

Research paper thumbnail of Stroke: Imaging and Intervention

Research paper thumbnail of Wake Up Call: Vascular Malformations

Research paper thumbnail of Dangerous Arterial Connections In The Head And Neck: Avoiding Neurological Complications

Research paper thumbnail of Intracranial Stenting in Acute Stroke

Research paper thumbnail of Cranio-Facial Vascular Anomalies: Update on Diagnosis and Interventional Management

Research paper thumbnail of Stroke Set Up and Workflow

Research paper thumbnail of Newer Generation Hydrogel Coils: Clinical Experience with Hydrosoft Helical and 3D

Research paper thumbnail of Stroke Intervention: From Basics to Advanced

Research paper thumbnail of Dural Arteriovenous Fistula

Research paper thumbnail of Off-label Use of Flow Diverters

Research paper thumbnail of Acute ischemic stroke. Introduction

Techniques in vascular and interventional radiology, 2012

Research paper thumbnail of Interaction between time to treatment and reperfusion therapy in patients with acute ischemic stroke

Journal of NeuroInterventional Surgery, 2013

‘Time is brain’ is a slogan that has been used by stroke advocacy groups to raise public awarenes... more ‘Time is brain’ is a slogan that has been used by stroke advocacy groups to raise public awareness that stroke is a medical emergency which requires timely treatment.1 Similarly, the acronym FAST (face, arm, speech, time) has been advertised as an easy way to remember the most common stroke symptoms and the need to act quickly.2 The time dependent nature of brain injury following an ischemic event has been characterized in animal experiments. Early studies have shown that brain tissue gradually undergoes irreversible damage following an acute ischemic stroke. These studies suggest that infarct growth can be described by a logarithmic or a sigmoidal function. The rate at which tissue transitions from reversible to irreversible injury is dependent on the depth of the ischemia; with mild reductions in cerebral blood flow, brain tissue remains viable for a relatively long duration, whereas cerebral injury becomes irreversible rapidly when cerebral blood flow is severely impaired (figure 1).3 ,4 Another factor that determines the rate at which tissue undergoes irreversible ischemic injury is the type of tissue that is involved. For example, gray matter, which has a higher metabolic demand, is more susceptible to ischemia than white matter.5 The average rate of neuronal loss in humans is estimated to be 1.9 million neurons per minute during the first 10 h after stroke onset.1 These data indicate that stroke treatments aimed at restoring blood flow are most effective when they are initiated early. Figure 1 Schematic representation of infarct volume evolution. A schematic representation of the evolution of infarct volume is shown for three hypothetical scenarios: the patient with a severe reduction in cerebral blood flow (CBF) (purple line) experiences rapid expansion of the infarct, which reaches its final volume early; moderate growth is seen in the patient with a …

Research paper thumbnail of Valor preditivo da distensão de alças intestinais em radiografias no prognóstico de enterocolite necrosante

Radiologia Brasileira, 2007

OBJETIVO: Avaliar o valor prognóstico da distensão de alças intestinais observada em radiografias... more OBJETIVO: Avaliar o valor prognóstico da distensão de alças intestinais observada em radiografias na evolução e mortalidade de neonatos com enterocolite necrosante. MATERIAIS E MÉTODOS: Nas radiografias de abdome de 53 pacientes obtidas no momento da suspeita diagnóstica de enterocolite necrosante, foi realizada a medida do diâmetro da alça mais distendida (AD), assim como a distância entre a borda superior da primeira vértebra lombar e a borda inferior da segunda (L1-L2), a distância entre as bordas laterais dos pedículos da primeira vértebra lombar (L1), e foram estabelecidas as associações entre AD/L1-L2 e AD/L1. Esta medida foi considerada como possível determinante de potenciais complicações, intervenção cirúrgica e mortalidade. RESULTADOS: Os pacientes que necessitaram de tratamento cirúrgico, aqueles que tiveram complicações durante a evolução e aqueles que morreram da doença tiveram a relação entre AD e AD/L1-L2 maiores (p < 0,05). Os valores de AD/L1 e a localização da a...

Research paper thumbnail of Percutaneous cholecystostomy: a nonsurgical therapeutic option for acute cholecystitis in high-risk and critically ill patients

Sao Paulo Medical Journal, 2003

Percutaneous cholecystostomy offers a potentially important type of therapy for critically ill pa... more Percutaneous cholecystostomy offers a potentially important type of therapy for critically ill patients with acute cholecystitis who present high risk when undergoing laparotomy or laparoscopy under general anesthesia. It offers a distinct advantage for these kinds of patients by avoiding the risks of the surgical intervention. Percutaneous cholecystostomy is a safe and effective minimally invasive procedure with a high success rate and low procedure-related complications. It should be considered not only in temporary management of calculous cholecystitis, but also in definitive treatment in cases of acalculous cholecystitis.

Research paper thumbnail of Extrarenal Wilms' tumor—A case report

Journal of Pediatric Surgery, 1988

The authors present a literature review on pulmonary embolism and conclude that pulmonary embolec... more The authors present a literature review on pulmonary embolism and conclude that pulmonary embolectomy is indicated in patients in whom thrombolytic therapy is contraindicated, or in those who are so compromised that a trial of medical management is not warranted and in those deteriorating on thrombolytic therapy. They state that patients with acute massive pulmonary emboli should be transferred to a center with full cardiopulmonary bypass capabilities.

Research paper thumbnail of MRI findings in the diagnosis and monitoring of rasmussen's encephalitis

Arquivos de Neuro-Psiquiatria, 2009

Rasmussen's encephalitis is a devastating syndrome of multifocal brain dysfunction and focal ... more Rasmussen's encephalitis is a devastating syndrome of multifocal brain dysfunction and focal seizures. Magnetic resonance (MR) findings, associated with clinical data and electroencephalogram (EEG), may indicate the diagnosis and could be an indicative of prognosis. We studied 5 patients with Rasmussen's encephalitis, assessing clinical history and MR images. All patients had refractory focal seizures with a predominant motor component associated with hemispheric atrophy, that was proportional to severity of disease and neurological deficits in these patients. Gray and white matter abnormal signal on T2 MR images were found in patients who had hemiparesis. It was not related to the duration of the disease but to aggressiveness. MR proton spectroscopy in severe disease showed lactate and choline increase and decreased NAA, reflecting neuronal and axonal loss, gliosis and elevated membrane turnover and recent - crisis (not controlled). MR studies, in addition to help in diagno...