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Biomarkers, intravascular ultrasound and near-infrared spectroscopy in the assessment of vulnerable atherosclerotic plaque
Štěchovský, Cyril ; Hájek, Petr (advisor) ; Krajina, Antonín (referee) ; Kaňovský, Jan (referee)
Biomarkers, Intravascular Ultrasound and Near-Infrared Spectroscopy in the Assessment of Vulnerable Atherosclerotic Plaque Abstract The thesis describes pathophysiology of a vulnerable atherosclerotic plaque, detection of the vulnerable plaque in the stenosis of the internal carotid artery (ICA), and optimalization of carotid stenting (CAS) with near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) imaging. NIRS detects lipid core of the vulnerable lipid rich plaque (LRP). We demonstrated safety of NIRS-IVUS imaging during CAS. LRP was detected in one third of ICAs before CAS. Lipid signal was not correlated with plaque morphology (IVUS), biomarkers or clinical variables. CAS caused significant decrease of the lipid signal. Angiography overestimated severity of stenosis of the ICA and vastly underestimated residual stenosis after CAS. Presence of the LRP in the stenosis was neither associated with periprocedural neurological complications of CAS nor long-term adverse cardiovascular events. IVUS identified planimetric features associated with long-term restenosis or stent occlusion. After a median follow-up of 31 months, repeated NIRS-IVUS of the implanted stents showed significant expansion of the stents, diffuse neointimal hyperplasia and further reduction of the lipid signal. We assume,...
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Structural and hemodynamic characteristics of atherosclerotic plaques in carotid arteries with relation to endovascular manipulation during carotid artery stenting.
Špaček, Miloslav ; Zemánek, David (advisor) ; Malík, Jan (referee) ; Pařenica, Jiří (referee)
Atherosclerotic diseases including stroke are the leading causes of morbidity, mortality as well as disability in industrialized countries. Carotid endarterectomy was long considered the stan- dard approach for the treatment of atherosclerotic carotid disease, one of major causes of stroke. Over time, carotid artery stenting (CAS) has evolved as an alternative approach and is considered equivalent to surgical treatment in selected patients. Particularly in the last years, CAS has gained attention with the increasing knowledge regarding atherosclerotic plaque and cerebrovascular flow. In our study, we focused on patients undergoing CAS and evaluated structural and hemodynamic characteristics of atherosclerotic plaques together with relation to endovascular manipulation. The major part of the study includes transcranial doppler ultrasound evaluation which is able to detect flow in major cerebral arteries as well as to detect microembolizations of atherosclerotic particles during CAS. In eligible patients, we investigated the usefulness of cerebrovascular reserve (CVR) testing to predict severe hemodynamic changes in ipsilateral middle cerebral artery induced by temporary carotid occlusion during proximally protected CAS. CVR was tested by means of a breath-holding test and ophthalmic artery flow...
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Therapeutic use of ultrasound in patients with cerebrovascular diseases.
Kuliha, Martin ; Školoudík, David (advisor) ; Beneš, Vladimír (referee) ; Tomek, Aleš (referee)
Background: Sonolysis is an important factor in therapeutic use of ultrasound in patients with cerebrovascular diseases, it is ultrasound induced lysis of thrombus or embolus. The aim of this work was to asses safety and efficacy of therapeutic ultrasound effect (sonolysis) in acute stroke patients and in patients undergoing carotid artery intervention. First partial aim of this work was to confirm the safety and efficacy of endovascular sonolysis by using the EkoSonic Endovascular System in subjects with acute ischemic stroke. Second partial aim of this work was to test the clinical efficacy of sonolysis for reducing the risk of incidence of new brain ischaemic lesions detected on brain magnetic resonance imaging in patients undergoing elective CEA or CAS for severe internal carotid stenosis. In addition, we assessed the effects of sonolysis on cognitive function, morbidity, and mortality at 30 days post-surgery. Methods: Patients with acute ischemic stroke and occlusion of the middle cerebral artery or basilar artery were enrolled consecutively to the prospective study tested safety and efficacy of endovascular sonolysis using the EkoSonic Endovascular System (EKOS) in patients with acute stroke. The control group (44 MCA and 12 BA occlusions) was selected from historical controls. EkoSonic...
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