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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Jämförelsestudie för grey scale median (GSM) värde för plack i carotis från ultraljud med två olika bildinställningar / Comparison of grey scale median (GSM) measurement in carotis plaque with ultrasound using two different image settings

Teodorescu, Crina January 2021 (has links)
Plack i arteria carotis kan ha olika utseende beroende på innehåll och morfologi. Det kan vara lågekogena eller högekogena plack. De lågekogena placken är mest problematiska eftersom de består av lipider och inflammationsceller som ger en mjuk konsistens och kan spricka och ledda till embolisering med stroke och kardiovaskulära incidenter som följd. För mätning av plack-ekogenicitet används i forskningssyfte ett GSM-värde, grey scale median som mäts med en ultraljudapparat med GSM-inställning. Ju lägre GSM-värde desto mer lågekogen är placken. Syftet med denna studie är att jämföra två GSM-värde för samma plack, den ena mätt med ultraljudstandardinställning och den andra mätt med GSM-inställningen för att avgöra om det blir en bra överensstämmelse mellan värdena. Om så är fallet innebär detta att plack-ekogenicitet kan avgöras i framtiden med mätning av GSM-värde med en ultraljudsapparat med standardinställning i forskningssyfte. Resultatet visade att det fanns en god överensstämmelse mellan en stor del av GSM-värdena, men det fanns en del värde där det blev en signifikant skillnad som gjorde att studien inte var tillräcklig övertygande för förväntade utfallet. / Plaque in the carotid artery can have different appearances depending on the content and morphology. It can be echolucent or more-echogenic plaques. The echolucent plaques are most problematic because they consist of lipids and inflammatory cells that give a soft consistency and can crack and lead to embolization with stroke and cardiovascular incidents as a result. For measuring plaque echogenicity for research purposes, a GSM value, gray scale median is used and is measured with an ultrasound device with a GSM setting. The lower the GSM value, the lower echolucent is the plaque. The purpose of this study is to compare two GSM values for the same plaque, one measured with the ultrasonic standard setting and the other measured with the GSM setting to determine if there is a good agreement between the values. If this is the case, this means that plaque echogenicity can be determined in the future by measuring GSM value with an ultrasound device with a standard setting for research purpose. The results showed that there was a good agreement between a large part of the GSM values, but there were some values where there was a significant difference which made the study not sufficiently convincing for the expected outcome.
132

Nachweis von Mikroemboliesignalen mittels transkraniellem Dopplerultraschall nach Stentimplantation der Arteria carotis interna

Zerweck, Christof 21 January 2016 (has links)
Hintergrund: Das Auftreten von frühen postinterventionellen Komplikationen nach Stenting der Arteria carotis interna (ACI) wird auf die Embolisierung von Material aus dem Stentsegment zurückgeführt. Zerebrale Thrombembolien können nicht invasiv mittels transkraniellem Dopplerultraschall (TCD) als mikroembolische Signale (MES) detektiert werden. Studienziel : Die Studie wurde durchgeführt um Prädiktoren zu finden, welche eine hohe Anzahl von MES im Intervall einer Stunde nach dem Eingriff voraussagen könnten. Methodik: Bei 134 konsekutiven Patienten, die ein Stenting der ACI erhielten, wurde postinterventionell über eine Stunde eine TCD der ipsilateralen Arteria cerebri media durchgeführt. Zur Identifizierung von klinischen, morphologischen und prozedurabhängigen Parametern für vermehrte MES, wurde eine multivariate logische Regressionsanalyse durchgeführt. Ergebnisse: Bei 134 Patienten (111 männlich, 23 weiblich, mittleres Alter 69,7 Jahre) wurden in 38% MES detektiert (Mittelwert 4 MES/h; Streuung von 1-62MES/h). Zwei Variablen waren mit einer erhöhten postinterventionellen MES Rate vergesellschaftet. Diese waren: Symptomatische Läsionen (p=0,048) und erhöhtes Gesamtcholesterin (p=0,037). Die duale Thrombozytenaggregationshemmung (ASS und Clopidogrel) konnte als unabhängiger Prädiktor (p=0,0001) für eine erniedrigte MES Rate festgestellt werden. Schlussfolgerungen: Postinterventionelle MES konnten am häufigsten bei symptomatischen Läsionen und bei Patienten mit Hypercholesterinämie festgestellt werden. Deren Anzahl viel im Verlauf ab. Das Stentdesign hatte keinen Einfluss auf die Anzahl der gemessenen MES. Die Kombinationstherapie mit ASS und Clopidogrel war ein Prediktor für eine erniedrigte cerebrale Embolisationsrate. Die TCD der MES Rate könnte eine brauchbare Methode sein um mögliche Risikofaktoren für neurologische Komplikationen nach Stenting der ACI zu entdecken und somit die Sicherheit der Stentingprozedur der ACI zu verbessern.
133

The value of noncoronary atherosclerosis for identifying coronary artery disease: Results of the Leipzig LIFE Heart Study

Weissgerber, Alexander 26 July 2018 (has links)
No description available.
134

Familiární hyperlipoproteinémie a další rizikové faktory kardiovaskulárních onemocnění u mužů s erektilní dysfunkcí / Familiar hyperlipoproteinemias and other risk factors of cardiovascular diseases in men with erectile dysfunction

Prusíková, Martina January 2012 (has links)
Background: The relationship between erectile dysfunction and risk factors of atherosclerosis has been confirmed by a number of previous investigations. There are also plausible pathophysiological mechanisms explaining the observed association. One of the tested hypotheses in our work was the assumption that risk factors of atherosclerosis would be more prevalent in men with erectile dysfunction than in controls selected from the representative sample of the Czech population. Our work did not confirm this hypothesis. Most likely explanation can be greater representation of younger-middle aged men in our group than in the Czech post-Monica study in which the age distribution was equal. On the other hand authors of the Czech post-Monica study admit worse compliance in younger participants of their survey. Nevertheless, the risk factors of atherosclerosis occur very frequently in males with erectile dysfunction. Results: In our group mean cardiovascular risk calculated according to the SCORE chart was 3.39% (±3,39). In the Czech post-MONICA study conducted between 2007 and 2008 the mean SCORE risk reached 2.47%. There was a trend, though not statistically significant, towards direct relationship between the severity of ED and the SCORE CVD risk. Asymptomatic atherosclerosis was detected in 56.25% of our study...
135

Clinical Outcomes of Second- versus First-Generation Carotid Stents: A Systematic Review and Meta-Analysis

Mazurek, Adam, Malinowski, Krzysztof, Rosenfield, Kenneth, Capoccia, Laura, Speziale, Francesco, de Donato, Gianmarco, Setacci, Carlo, Wissgott, Christian, Sirignano, Pasqualino, Tekieli, Lukasz, Karpenko, Andrey, Kuczmik, Waclaw, Stabile, Eugenio, Metzger, David Christopher, Amor, Max, Siddiqui, Adnan H., Micari, Antonio, Pieniazek, Piotr, Cremonesi, Alberto, Schofer, Joachim, Schmidt, Andrej, Musialek, Piotr 04 December 2023 (has links)
Background: Single-cohort studies suggest that second-generation stents (SGS; “mesh stents”) may improve carotid artery stenting (CAS) outcomes by limiting peri- and postprocedural cerebral embolism. SGS differ in the stent frame construction, mesh material, and design, as well as in mesh-to-frame position (inside/outside). Objectives: To compare clinical outcomes of SGS in relation to first-generation stents (FGSs; single-layer) in CAS. Methods: We performed a systematic review and meta-analysis of clinical studies with FGSs and SGS (PRISMA methodology, 3302 records). Endpoints were 30-day death, stroke, myocardial infarction (DSM), and 12-month ipsilateral stroke (IS) and restenosis (ISR). A random-effect model was applied. Results: Data of 68,422 patients from 112 eligible studies (68.2% men, 44.9% symptomatic) were meta-analyzed. Thirty-day DSM was 1.30% vs. 4.11% (p < 0.01, data for SGS vs. FGS). Among SGS, both Casper/Roadsaver and CGuard reduced 30-day DSM (by 2.78 and 3.03 absolute percent, p = 0.02 and p < 0.001), whereas the Gore stent was neutral. SGSs significantly improved outcomes compared with closed-cell FGS (30-day stroke 0.6% vs. 2.32%, p = 0.014; DSM 1.3% vs. 3.15%, p < 0.01). At 12 months, in relation to FGS, Casper/Roadsaver reduced IS (−3.25%, p < 0.05) but increased ISR (+3.19%, p = 0.04), CGuard showed a reduction in both IS and ISR (−3.13%, −3.63%; p = 0.01, p < 0.01), whereas the Gore stent was neutral. Conclusions: Pooled SGS use was associated with improved short- and long-term clinical results of CAS. Individual SGS types, however, differed significantly in their outcomes, indicating a lack of a “mesh stent” class effect. Findings from this meta-analysis may provide clinically relevant information in anticipation of large-scale randomized trials.
136

NOX4 mRNA correlates with plaque stability in patients with carotid artery stenosis

Hofmann, Anja, Frank, Frieda, Wolk, Steffen, Busch, Albert, Klimova, Anna, Sabarstinski, Pamela, Gerlach, Michael, Egorov, Dmitry, Kopaliani, Irakli, Weinert, Sönke, Hamann, Bianca, Poitz, David M., Brunssen, Coy, Morawietz, Henning, Schröder, Katrin, Reeps, Christian 06 June 2024 (has links)
Carotid artery stenosis (CAS) develops from atherosclerotic lesions and plaques. Plaque rupture or stenosis may result in occlusion of the carotid artery. Accordingly, the asymptomatic disease becomes symptomatic, characterized by ischemic stroke or transient ischemic attacks, indicating an urgent need for better understanding of the underlying molecular mechanisms and eventually prevent symptomatic CAS. NOX4, a member of the NADPH oxidase family, has anti-atherosclerotic and anti-inflammatory properties in animal models of early atherosclerosis. We hypothesized that NOX4 mRNA expression is linked to protective mechanisms in CAS patients with advanced atherosclerotic lesions as well. Indeed, NOX4 mRNA expression is lower in patients with symptomatic CAS. A low NOX4 mRNA expression is associated with an increased risk of the development of clinical symptoms. In fact, NOX4 appears to be linked to plaque stability, apoptosis and plaque hemorrhage. This is supported by cleaved caspase-3 and glycophorin C and correlates inversely with plaque NOX4 mRNA expression. Even healing of a ruptured plaque appears to be connected to NOX4, as NOX4 mRNA expression correlates to fibrous cap collagen and is reciprocally related to MMP9 activity. In conclusion, low intra-plaque NOX4 mRNA expression is associated with an increased risk for symptomatic outcome and with reduced plaque stabilizing mechanisms suggesting protective effects of NOX4 in human advanced atherosclerosis.
137

Wertigkeit der Digitalen Subtraktionsangiographie (DSA) gegenüber der Magnetresonanzangiographie (MRA) in der Diagnostik der hirnversorgenden Halsgefässe

Roth, Claudia 25 February 2004 (has links)
Das Ziel: der Arbeit war die Überprüfung der Aussagekraft der MRA in time-of-flight-technique der Arteria caroits bei 1,0 Tesla im Vergleich zur intaarteriellen DSA und der Wertigkeit in der Einsatzfähigkeit in der klinischen Routine bei der Diagnostik von Carotisstenosen. 101 Patienten wurden zur Abklärung einer Stenose der Arteria carotis vergleichend mittels TOF-MRA und i.a. DSA der Arteriae carotis untersucht. Morphologische Veränderungen wurden für sämliche Gefässe erfasst, wobei die Stenosen der Arteriae carotis entsprechend den NASCET-Kriterien graduiert wurden (geringgrade, mittelgradige,hochgradige Stenose oder Verschluss).Die Ergebnisse wurden mit folgenden drei verschiedenen statistischen Tests ausgewertet: Kappa Test, gewichteter Kappa Test und Intraklassenkorrelationskoeffizient. Von den 84 in die Auswertung eingebezogenen Gefässen wurden 66 Stenosen in der DSA als geringgradig klassifiziert. In dieser Kategorie wurden 60 dieser Stenosen von der MRA korrekt als geringgradig klassifiziert. In der DSA wurden 60 Stenosen der Arteria carotis als mittelgradig klassifiziert. 29 dieser Stenosen wurden von der MRA korrekt als mittelgradig eingeschätzt. 21 Stenosen wurden von der DSA als hochgradig klassifiziert. 20 dieser Stenosen wurden von der MRA korrekt als hochgradige Stenosen eingeschätzt. Die 16 kompletten Gefäsverschlüsse wurden alle von der MRA detektiert. Der Kappa Test ergab eine starke Korrelation der Ergebnisse. Insgesamt zeigte sich eine gute Überstimmung zwischen MRA und DSA. Aber gerade im Bereich der mittelgradigen Stenosen neigte die MRA dazu den Stenosegrad zu überschätzen. Das Ziel der Gefässdiagnostik ist eine präzise und reproduzierbare Bestimmung des Stenosegrades. Die Magnetresonanzangiographie kann als eine akkurate und zuverlässige Methode zur Bestimmung von Carotisstenosen angesehen werden / The purpose was to evaluate the efficiacy of the time-of-flight MRA of the carotid artery with a 1.0 Tesla system in comparison to intraarterial digital subtraction angiography for the assessment of carotid artery disease. 101 patients with suspected stenosis of the carotid artery were examined with a 1.0 Tesla scanner in time-of-flight-technique and with the selective i.a. DSA in parallel. Morphological pathologies were registered for all arteries, stenosis of the internal carotid artery of both examinations were blindly graded by applying the NASCET criteria (mild, moderately, severely or occluded). Three different assessment methods were conducted for the MRA data. Kappa, weighted kappa, intraclass correlation were calculated for MRA results compared to DSA. Of the 84 common carotid bifurcation, 66 were classified as mild stenosis by DSA. In this category, MRA correctly identified 60 of these as mild stenosis. Among 60 common carotid artery bifurcation graded as moderate by DSA, 29 were correctly graded as moderate by MRA. Among 21 common carotid artery bifurcation graded as severe by DSA, 20 of these were correctly graded by the MRA. There were 16 complete occlusions which were all correctly graded by MRA. A good kappa value was calculated for the data. In general the MRA were considered to find a good agreement with the DSA, but tended to overestimate stenosis, especially in the range of moderate stenosis. The aim of diagnosis is exact grading of carotid stenosis. MRA with its high agreement with DSA can be regarded as an accurate screening method of the common carotid bifurcation.
138

Syndrom karotického pahýlu / The Carotid Stump Syndrome

Hrbáč, Tomáš January 2012 (has links)
Introduction: Internal Carotid Stump Syndrome may be one of the possible causes of ischemic stroke (iCMP), as well as retinal infarction (RI). Syndrome of the occluded internal carotid (ACI) (stump syndrome) is a nosological unit, which is characterized by an onset of ipsilateral iCMP or RI of thromboembolic ethiology in patients with occlusion of ACI via the externa carotid or arteria ophthalmica. In my thesis, I have concentrated upon the specification of the stump syndrome, its diagnostics and treatment; furthermore I have assessed the appropriateness of surgical approach in comparison with conservative approach. Material and methods: A total of 621 patients with occlusion were treated in two centres in the course of five years. In a group of 40 patients, the ACI occlusion was detected sonographically, the length of the occluded ACI being >5 mm, with normal vasoreactivity based upon SPECT CO2 and excluded cardiogenic cause of iCMP. The patients were divided in two groups - surgical and conservative. Patients were monitored in 6-month intervals for the total period of four years. Results: No RI or iCMP were detected in the surgical group; one patient died six months after surgery. We observed one case of amaurosis fugax in the conservative group. Conclusion: Ultrasound examination is a fully sufficient...
139

Syndrom karotického pahýlu / The Carotid Stump Syndrome

Hrbáč, Tomáš January 2012 (has links)
Introduction: Internal Carotid Stump Syndrome may be one of the possible causes of ischemic stroke (iCMP), as well as retinal infarction (RI). Syndrome of the occluded internal carotid (ACI) (stump syndrome) is a nosological unit, which is characterized by an onset of ipsilateral iCMP or RI of thromboembolic ethiology in patients with occlusion of ACI via the externa carotid or arteria ophthalmica. In my thesis, I have concentrated upon the specification of the stump syndrome, its diagnostics and treatment; furthermore I have assessed the appropriateness of surgical approach in comparison with conservative approach. Material and methods: A total of 621 patients with occlusion were treated in two centres in the course of five years. In a group of 40 patients, the ACI occlusion was detected sonographically, the length of the occluded ACI being >5 mm, with normal vasoreactivity based upon SPECT CO2 and excluded cardiogenic cause of iCMP. The patients were divided in two groups - surgical and conservative. Patients were monitored in 6-month intervals for the total period of four years. Results: No RI or iCMP were detected in the surgical group; one patient died six months after surgery. We observed one case of amaurosis fugax in the conservative group. Conclusion: Ultrasound examination is a fully sufficient...
140

Estudo da anatomia endoscópica do acesso transpterigóideo e da artéria carótida interna por via endonasal / Anatomical study of the endoscopic endonasal transpterygoid approach and the internal carotid artery

Fortes, Felipe Sartor Guimarães 17 August 2011 (has links)
INTRODUÇÃO. Durante a última década, os avanços tecnológicos, o maior domínio da anatomia e das técnicas operatórias e de reconstrução da base do crânio por via endonasal propiciaram a expansão da cirurgia endoscópica para além dos limites da sela túrcica. O acesso transpterigóideo é uma etapa comum ao acesso as fossas cranianas média e posterior, e o conhecimento da anatomia endoscópica da artéria carótida interna (ACI) é um ponto fundamental e comum a estes acessos. OBJETIVO. Descrever a anatomia endoscópica relacionada ao acesso transpterigóideo e da ACI utilizando um modelo anatômico em cabeças cadavéricas frescas procurando definir os parâmetros seguintes: reparos anatômicos do acesso endoscópico a região supra e infrapetrosa, os limites para exposição endoscópica da ACI, os reparos anatômicos para localização dos seus segmentos lacerum, petroso e parafaríngeo. MÉTODOS. Foi realizado estudo anatômico em 20 espécimes (10 cabeças) de cadáveres frescos. As cabeças foram previamente preparadas com a injeção intravascular de silicone corado para enaltecer as estruturas vasculares (ACI, artéria maxilar e seus ramos e seio cavernoso). Em todos os casos foi realizado o acesso transpterigóideo às regiões supra e infrapetrosa, assim como a fossa infratemporal, e a dissecção endoscópica da ACI. RESULTADOS. A injeção de silicone corado no sistema arterial e venoso proporcionou modelo anatômico adequado para dissecção e documentação do acesso transpterigóideo assim como dos diferentes segmentos da ACI. A dissecção por etapas proporcionou exposição adequada da ACI do seu segmento cavernoso ao parafaríngeo distal. O acesso transpterigóideo forneceu exposição adequada do segmento lacerum da ACI e região suprapetrosa e seus principais reparos anatômicos foram o nervo vidiano, nervos maxilar e mandibular (V2, V3) e gânglio de Gasser. A exposição caudal da ACI (segmentos petroso e parafaríngeo) e região infrapetrosa requer maxilectomia medial para exposição e remoção de todo o processo pterigóideo, seguida pela ressecção da tuba auditiva e do tecido fibrocartilaginoso do forame lacerum. Os principais reparos anatômicos desta etapa foram a tuba auditiva e V3. CONCLUSÃO. Durante o acesso endoscópico à região suprapetrosa, o nervo vidiano, os ramos maxilar e mandibular do nervo trigêmeo (V2 e V3) e o gânglio de Gasser são reparos anatômicos para localização da artéria carótida interna e fossa craniana média. Durante o acesso endoscópico à região infrapetrosa, o tecido fibrocartilaginoso do forame lacerum, a tuba auditiva e o nervo mandibular (V3) são reparos anatômicos para identificação da artéria carótida interna. O acesso endoscópico endonasal por etapas permite acesso à artéria carótida interna extracraniana desde o segmento cavernoso até seu segmento parafaríngeo inferiormente ao nível do assoalho da cavidade nasal. O reparo anatômico para localização do segmento lacerum e porção horizontal do segmento petroso da ACI é o nervo vidiano; para as porções petrosa horizontal junto ao joelho posterior e canal carotídeo os reparos anatômicos são o nervo mandibular (V3), forame oval, tecido fibrocartilaginoso do forame lacerum e a tuba auditiva; para o segmento parafaríngeo os reparos anatômicos são o tronco posterior do nervo mandibular (V3) e a tuba auditiva / INTRODUCTION. During the last decade, the technological advances, the mastery of the anatomy and operative techniques and skull base reconstruction using endonasal approaches have propelled endoscopic surgery for beyond the limits of sella turcica. The transpterygoid approach is a common step of the endoscopic approach to the middle and posterior cranial fossa and knowledge of the endoscopic anatomy of the internal carotid artery (ICA) is a common and paramount point to these approaches. OBJECTIVE. Describe the endoscopic anatomy related to the transpterygoid approach and ICA using an anatomical model with fresh human cadaveric heads to define: anatomical landmarks related to the endoscopic supra and infrapetrous areas approach, limits for endoscopic exposure of the ICA, anatomical endoscopic landmarks to lacerum, petrous and parapharyngeal ICA segments. METHODS. An anatomical study was performed using 20 specimens (10 heads) of fresh cadaveric heads. The heads were previously prepared with the injection of colored silicone to enhance the vascular structures (ICA, maxillary artery and its branches and cavernous sinus). In all cases we performed the transpterygoid approach to the supra and infrapetrous areas, as well as the infratemporal fossa, and the endoscopic dissection of the ICA. RESULTS. The injection of colored silicone in the arterial and venous system provided an adequate anatomical model for dissection and documentation of the transpterygoid approach as well as the different segments of the ICA. A stepwise dissection provided adequate exposure of the ICA from its cavernous to the distal parapharyngeal segment. The transpterygoid approach provided adequate exposure of the lacerum segment of the ICA and suprapetrous area and the landmarks were the vidian nerve, maxillary and mandibular nerves (V2, V3) and the Gasserian ganglion. Exposure of the caudal ICA (petrous and parapharyngeal) and the infrapetrous area required a medial maxillectomy for exposure and resection of the entire pterygoid process, followed by the Eustachian tube and the fibrocartilaginous tissue of the foramen lacerum. The main anatomical landmarks to this step were V3 and the Eustachian tube. CONCLUSION. During the endoscopic approach to the suprapetrous area, the vidian nerve, the maxillary and mandibular divisions of the trigeminal nerve (V2, V3) and the Gasserian ganglion are the anatomical landmarks to the internal carotid artery and middle cranial fossa. During the endoscopic approach to the infrapetrous area, the fibrocartilaginous tissue of the foramen lacerum, the Eustachian tube and V3 are the landmarks to the internal carotid artery. A stepwise endoscopic endonasal approach provided access to the extracranial internal carotid artery from its cavernous to the parapharyngeal segment down to the level of the nasal fossa floor. The anatomical landmark to the lacerum and horizontal petrous segments of the internal carotid artery is the vidian nerve; to the horizontal petrous segment before the posterior bend and carotid canal, the anatomical landmarks are the mandibular nerve (V3), foramen ovale, fibrocartilaginous tissue of the foramen lacerum and the Eustachian tube; to the parapharyngeal segment, the anatomical landmarks are the posterior trunk of the mandibular nerve (V3) and the Eustachian tube

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