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1.
Can J Neurol Sci ; : 1-6, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38465386

RESUMO

The carotid artery is unique; it is the only vessel to bifurcate into a bulb larger than itself. The history of its anatomic description, understanding of its pathophysiology and evolution of its imaging are relevant to current controversies regarding measurement of stenosis, surgical/endovascular therapies and medical management of carotid stenosis in stroke prevention. Treatment decisions on millions of symptomatic and asymptomatic patients are routinely based on information from clinical trials from over 30 years ago. This article briefly summarizes the highlights of past research in key areas and discuss how they led to current challenges of diagnosis and treatment.

3.
Can J Neurol Sci ; 50(5): 651-655, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36245094

RESUMO

BACKGROUND AND PURPOSE: Cerebral emboli are generated by every step of standard carotid angioplasty and stenting. Primary carotid stenting (PCS) is a technique in which the use of balloon angioplasty (BA) is minimized to decrease the embolic load. The primary aim of this study is to establish the number of emboli generated by each step of primary stenting and determine the relationship to new diffusion (DWI) lesions on subsequent magnetic resonance imaging (MRI). METHODS: Eighty-five patients with severe, symptomatic carotid stenosis were prospectively recruited and underwent carotid stenting. Intraoperative transcranial Doppler was performed in 77 patients. The number and size of microemboli for each of seven procedural steps were recorded. Correlation was made with the number and location of new DWI lesions. RESULTS: PCS was performed in 73 patients. BA was required in 12 patients. The mean number of microemboli was 114, and most microemboli were generated by stent deployment, followed by BA. Balloon techniques generated significantly more emboli than primary stenting (p = 0.017). There was a significant relationship between total microemboli and new DWI lesions (p = 0.009), and between new DWI lesions in multiple territories and the severity of pretreatment stenosis (p = 0.002). CONCLUSIONS: During PCS, more emboli are generated by stent deployment than during any other stage of the procedure. When BA is necessary, more malignant emboli are generated but total emboli are unchanged and there is no difference in new diffusion lesions on MRI. PCS is safe and is not inferior to historical controls for the generation of new DWI lesions.


Assuntos
Estenose das Carótidas , Embolia , Embolia Intracraniana , Humanos , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Artérias Carótidas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Ultrassonografia Doppler Transcraniana , Stents , Imagem de Difusão por Ressonância Magnética , Embolia Intracraniana/diagnóstico por imagem , Embolia Intracraniana/etiologia , Embolia Intracraniana/patologia , Resultado do Tratamento
4.
Can J Neurol Sci ; 49(6): 741-745, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-34526172

RESUMO

The goal of effective neuroprotection in acute ischemic stroke remains elusive. Despite decades of experimental preclinical and clinical experience with innumerable agents, no strategy has proven to be beneficial in humans. As endovascular therapies mature and approach the limits of speed and efficacy, neuroprotection will become the next frontier of acute stroke care. This review will briefly summarize the history, preclinical and clinical triumphs and failures, and future directions of cerebral neuroprotection.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Fármacos Neuroprotetores , Acidente Vascular Cerebral , Humanos , Neuroproteção , Acidente Vascular Cerebral/tratamento farmacológico , Isquemia Encefálica/terapia , Isquemia Encefálica/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico
5.
Can J Neurol Sci ; 49(3): 364-367, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33988114

RESUMO

BACKGROUND: There is an association between anterior cerebral artery vessel asymmetry and anterior communicating artery aneurysm, presumably based on flow dynamics. The purpose of this study is to investigate the potential relationship between aortic arch branching patterns and incidence of intracranial aneurysm. METHODS: This study included patients scanned over 1 year at our tertiary care center who underwent high-resolution imaging (computed tomography angiography or digital subtracted angiogram) of the head and neck arteries, aortic arch, and superior mediastinum. Exclusion criteria included patients with suboptimal images. Patient age, gender, aortic arch branching pattern, and the presence, location, and number of aneurysms were documented. RESULTS: Among the 1082 patients analyzed, 250 (23%) patients had a variant aortic arch branching pattern, 22 (8.8%) of whom had aneurysms. There were 104 patients with 126 aneurysms, with majority of patients with normal aortic arch branching pattern (n = 82, 79%). The most common variant was a common origin of the left common carotid artery and brachiocephalic trunk with or without direct origin of the left vertebral artery. Twenty-two patients with aneurysms had an aberrant aortic arch (21%), compared to 232 patients without an aneurysm (24%). Fischer exact test showed no statistically significant difference between the incidence of aneurysm with different aortic arch variant groups (two-tailed p-value = 0.715). CONCLUSION: To our knowledge, this is the first study to examine the association between aortic arch branching patterns and incidence of intracranial aneurysm. No significant association was found between aortic arch branching pattern and the incidence of intracranial aneurysm.


Assuntos
Aorta Torácica , Aneurisma Intracraniano , Aorta Torácica/diagnóstico por imagem , Tronco Braquiocefálico , Artéria Carótida Primitiva , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/epidemiologia , Artéria Vertebral
7.
Can J Neurol Sci ; 48(2): 172-188, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32669144

RESUMO

Interventional neuroradiology (INR) has evolved from a hybrid mixture of daring radiologists and iconoclastic neurosurgeons into a multidisciplinary specialty, which has become indispensable for cerebrovascular and neurological centers worldwide. This manuscript traces the origins of INR and describes its evolution to the present day. The focus will be on cerebrovascular disorders including aneurysms, stroke, brain arteriovenous malformations, dural arteriovenous fistulae, and atherosclerotic disease, both intra- and extracranial. Also discussed are cerebral vasospasm, venolymphatic malformations of the head and neck, tumor embolization, idiopathic intracranial hypertension, inferior petrosal venous sinus sampling for Cushing's disease, and spinal interventions. Pediatric INR has not been included and deserves a separate, dedicated review.


Assuntos
Malformações Vasculares do Sistema Nervoso Central , Transtornos Cerebrovasculares , Embolização Terapêutica , Malformações Arteriovenosas Intracranianas , Acidente Vascular Cerebral , Vasoespasmo Intracraniano , Malformações Vasculares do Sistema Nervoso Central/diagnóstico por imagem , Malformações Vasculares do Sistema Nervoso Central/terapia , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/terapia , Criança , Humanos , Acidente Vascular Cerebral/terapia
10.
J Neurointerv Surg ; 10(2): 150-155, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28465402

RESUMO

INTRODUCTION: Brain arteriovenous malformations are abnormal connections between arteries and veins without an intervening capillary bed. Endovascular glue embolization with N-butyl cyanoacrylate (NBCA) is an accepted form of treatment. The reported complication rates vary widely from 2% to 15%, and timing of polymerization appears to play a major role. Additionally, the interaction between NBCA and vessel surface as well as the presence of biological catalysts are poorly understood. METHODS: Polymerization time was measured for mixtures of Lipiodol/NBCA of 50/50, 70/30, and 60/40. The influence of pH, temperature, and the presence of biological catalysts on polymerization time was investigated. Contact angles were measured on polyvinyl alcohol cryogel (PVA-C), silicone, and endothelial surfaces in a submerged aqueous environment to assess physical surface interactions. High speed video analysis of glue injection through a microcatheter was performed to characterize simulated coaxial flow. RESULTS: NBCA polymerization rate increased with pH and temperature. A hydrophilic surface such as PVA-C was better than silicone at mimicking the physical properties of endothelium. Live endothelium provided a catalytic surface that at least doubled the rate of polymerization. Blood products further increased the polymerization rate in the following order (slowest to fastest): plasma, platelets, red blood cells (RBCs), and lysed RBCs. These factors could explain the discrepancy between in vitro and in vivo results reported in the current literature. High speed video analysis of NBCA injection showed dripping to jetting transition with significant wall effect which deviated from previous ideal assumptions. CONCLUSIONS: The determinants of NBCA polymerization rate are multifactorial and dependent mainly on the presence of biological catalysts coupled with flow related wall interaction.


Assuntos
Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Embucrilato/química , Embucrilato/metabolismo , Polimerização , Adesivos/administração & dosagem , Adesivos/química , Adesivos/metabolismo , Fístula Arteriovenosa/fisiopatologia , Fístula Arteriovenosa/terapia , Velocidade do Fluxo Sanguíneo/fisiologia , Embolização Terapêutica/métodos , Embucrilato/administração & dosagem , Óleo Etiodado/administração & dosagem , Óleo Etiodado/química , Óleo Etiodado/metabolismo , Humanos , Injeções , Malformações Arteriovenosas Intracranianas/fisiopatologia , Malformações Arteriovenosas Intracranianas/terapia
11.
J Neurosurg ; 128(4): 1028-1031, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28474993

RESUMO

The objective of this paper was to report a rare complication of basilar artery (BA) tourniquet treatment of a giant basilar tip aneurysm, and to discuss possible causes for the formation of a de novo giant posterior cerebral artery (PCA) aneurysm. A 34-year-old woman underwent satisfactory treatment of a ruptured giant basilar bifurcation aneurysm by BA ligation (Drake tourniquet) in 1985. She presented 25 years later with a new aneurysm in the left PCA, successfully treated by coil embolization. To the authors' knowledge, this is the first case of de novo aneurysm formation on a PCA, and the first de novo aneurysm reported as a complication of BA ligation therapy by Drake tourniquet. Long-term follow-up is necessary in patients with treated cerebral aneurysms, particularly those occurring in young patients, those with multiple aneurysms, those with complex posterior circulation aneurysms, and those undergoing flow diversion or flow-altering therapies.


Assuntos
Aneurisma Intracraniano/cirurgia , Complicações Pós-Operatórias/cirurgia , Torniquetes , Adulto , Aneurisma Roto/complicações , Angiografia Cerebral , Embolização Terapêutica , Feminino , Humanos , Aneurisma Intracraniano/complicações , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Procedimentos Neurocirúrgicos
12.
J Neurosurg ; 129(1): 205-210, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-28984516

RESUMO

Spontaneous intracranial hypotension (SIH) is a progressive clinical syndrome characterized by orthostatic headaches, nausea, emesis, and occasionally focal neurological deficits. Rarely, SIH is associated with neurocognitive changes. An epidural blood patch (EBP) is commonly used to treat SIH when conservative measures are inadequate, although some patients require multiple EBP procedures or do not respond at all. Recently, the use of a large-volume (LV) EBP has been described to treat occult leak sites in treatment-refractory SIH. This article describes the management of a patient with profound neurocognitive decline associated with SIH, who was refractory to conservative management and multiple interventions. The authors describe the successful use of an ultra-LV-EBP of 120 ml across multiple levels, the largest volume reported in the literature, and describe the technical aspects of the procedure. This procedure has resulted in dramatic and sustained symptom resolution.


Assuntos
Placa de Sangue Epidural/métodos , Hipotensão Intracraniana/terapia , Transtornos Neurocognitivos/terapia , Humanos , Hipotensão Intracraniana/complicações , Masculino , Pessoa de Meia-Idade , Transtornos Neurocognitivos/etiologia
13.
Can J Neurol Sci ; 44(5): 498-502, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28366179

RESUMO

BACKGROUND: In vitro models have suggested that stents affect atherosclerotic plaques symmetrically because of their outward radial forces. We evaluated the effects of stents on carotid plaque and the arterial wall using carotid ultrasound in carotid stenting patients to see whether these effects were borne out in vivo. METHODS: From a carotid stent database, 30 consecutive patients were selected. All had carotid Doppler ultrasound performed pre- and poststenting. The diameters of the lumen at the level of stenotic plaque pre- and poststenting, the dorsal and ventral plaque thickness, and of the outer arterial wall diameter were measured. Plaque thickness was measured at the level of maximal stenosis. Nonparametric tests were used to determine whether the stent effect and luminal enlargement were based on wall remodeling or on total arterial expansion. RESULTS: The patients were followed for an average of 22 months. Eighteen patients were male, with an average age of 70 years. A total of 87% of patients were symptomatic ipsilateral to the side of stenosis. Nine patients had angioplasty intraprocedurally. The luminal diameter increased poststenting in the region of severe stenosis. Plaque thickness, both ventrally and dorsally, decreased poststenting, with no significant difference between the ventral and dorsal plaque effects. The outer arterial wall diameters did not change. The measured lumen in the stent increased over time poststenting. CONCLUSIONS: Self-expanding nitinol stents alter the baseline ventral and dorsal plaque to a significant degree and do not significantly affect the native arterial wall and the overall arterial diameter.


Assuntos
Estenose das Carótidas/cirurgia , Placa Aterosclerótica/patologia , Stents , Idoso , Ligas/uso terapêutico , Prótese Vascular/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/terapia , Ultrassonografia Doppler/métodos
15.
20.
J Neurointerv Surg ; 8(4): 418-22, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25676148

RESUMO

BACKGROUND: Total body hypothermia is an established neuroprotectant in global cerebral ischemia. The role of hypothermia in acute ischemic stroke remains uncertain. Selective application of hypothermia to a region of focal ischemia may provide similar protection with more rapid cooling and elimination of systemic side effects. We studied the effect of selective endovascular cooling in a focal stroke model in adult domestic swine. METHODS: After craniotomy under general anesthesia, a proximal middle cerebral artery branch was occluded for 3 h, followed by 3 h of reperfusion. In half of the animals, selective hypothermia was induced during reperfusion using a dual lumen balloon occlusion catheter placed in the ipsilateral common carotid artery. Following reperfusion, the animals were sacrificed. Brain MRI and histology were evaluated by experts who were blinded to the intervention. RESULTS: 25 animals were available for analysis. Using selective hypothermia, hemicranial temperature was successfully cooled to a mean of 26.5 °C. Average time from start of perfusion to attainment of moderate hypothermia (<30 °C) was 25 min. Mean MRI stroke volumes were significantly reduced by selective cooling (0.050±0.059 control, 0.005±0.011 hypothermia (ratio stroke:hemisphere volume) (p=0.046). Stroke pathology volumes were reduced by 42% compared with controls (p=0.256). CONCLUSIONS: Selective moderate hypothermia was rapidly induced using endovascular techniques in a clinically realistic swine stroke model. A significant reduction in stroke volume on MRI was observed. Endovascular selective hypothermia can provide neuroprotection within time frames relevant to acute ischemic stroke treatment.


Assuntos
Oclusão com Balão/métodos , Isquemia Encefálica/terapia , Modelos Animais de Doenças , Hipotermia Induzida/métodos , Acidente Vascular Cerebral/terapia , Animais , Isquemia Encefálica/diagnóstico , Cateterismo/métodos , Acidente Vascular Cerebral/diagnóstico , Suínos
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