The aim - to assess the carotid artery angioplasty and stenting early and late results and influencing factors. Methods. The study assessed CAS procedures performed in 2006-2013. A total of 227 procedures performed in 211 patients, of which 156 (75.3%) males and 55 (24.7%) females. Results. The study revealed that CAS procedure duration among patient with 3 aortic arch type was significantly longer and the microemboli protection systems were used more frequently. Protection systems were used more frequently when the CAS procedure lasted longer. Protection systems in CAS procedure was used in 70.9% patients. In men and younger patients protection system has been used more frequently. Microemboli in the protection systems have been identified by 17.6% patients and were more determined using the EZ FilterWire and Emboshield-NAV protection system. Increased right ICA stenosis was more common in patients who smoke, and left ICA with a history of myocardial infarction and smoking. Protection system was often used in patients who have had severe left ICA stenosis. The lethality rate in the early post procedural period among men and women was 1.2% and 1.8%, and in 2-year period was 18.7% and 28.6%, respectively. The lethality rate during 2-year period, which have been used for protective systems have been lower. The possibility to experience complications (stroke or TIA) increased 3 aortic arch type and the right common carotid artery stenosis, reduced protection systems using. Focal... [to full text] / Darbo tikslas – įvertinti miego arterijų angioplastikos ir stentavimo ankstyvuosius ir vėlyvuosius rezultatus bei poveikį darančius veiksnius. Metodai. Tyrimo metu vertintos VMAS procedūros atliktos 2006-2013 metais. Iš viso buvo atliktos 227 procedūros 211 pacientų; iš jų 156 (75,3 proc.) vyrams ir 55 (24,7 proc.) moterims. Rezultatai. Tyrimas atskleidė, kad esant 3 aortos lanko tipui VMAS procedūros trukmė buvo reikšmingai ilgesnė, o mikroembolai apsaugos sistemose buvo nustatyti dažniau. Mikroembolai apsaugos sistemose buvo nustatyti dažniau kai VMAS procedūra truko ilgiau. Apsaugos sistemos atliekant VMAS procedūrą buvo naudotos 70,9 proc. pacientų. Vyrams ir jaunesnio amžiaus pacientams VMAS procedūros metu apsauga buvo taikyta dažniau. Mikroembolai apsaugos sistemose buvo nustatyti 17,6 proc. pacientų ir dažniau buvo nustatyti naudojant FilterWire EZ ir Embo-shield-NAV apsaugos sistemas. Didesnė dešinės VMA stenozė buvo dažnesnė rūkantiems pacientams, o kairės VMA sirgusiems miokardo infarktu bei rūkantiems. Apsauga dažniau buvo taikyta pacientams kurie turėjo didelio laipsnio kairės VMA stenozę. Ankstyvuoju po procedūriniu periodu vyrų ir moterų mirštamumas atitinkamai buvo 1,2 proc. ir 1,8 proc., o 2 metų laikotarpyje buvo 18,7 proc. ir 28,6 proc. Pacientų mirštamumas 2 metų laikotarpyje, kuriems buvo naudotos apsaugos sistemos buvo mažesnis. Galimybę patirti komplikacijas (GSI ar PSIP) didino 3 aortos lanko tipas ir dešinės bendrosios miego arterijos stenozė, mažino... [toliau žr. visą tekstą]

M.Cur. / Coronary stenting as a treatment method for the "in-between" patient with atherosclerosis was instituted in October 1991. It was initially used as secondary treatment to balloon angioplasty as "bail-out", when dissection or secondary closure of the coronary artery occurred. It has now become the primary method of treatment for atherosclerosis. It is apparent that there is a deficit in the information available to patients who have received a coronary stent. The objective of this study was therefore firstly to compile an information booklet for the patient who has received a coronary stent and secondly to set nursing guidelines for use on the implementation of this booklet. A literature study was undertaken on the following topics: atherosclerosis and its associated risk factors; the patient as an adult learner; coronary stents and the function of the nurse. This study showed that the literature covered the procedure of coronary stenting but not patient education. Interviews were conducted with two doctors that do coronary stenting as a method of treatment s as to determine what they see as import ant information to be given to these patients. Further interviews were conducted with patients that have received coronary stents to determine what they wanted and needed to know. From all the information gathered from the literature review and interviews, the information booklet was compiled, as well as the guidelines set for the nurse on how to implement the booklet.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13435号 / 論医博第2234号 / 新制||医||1054(附属図書館) / (主査)教授 石見 拓, 教授 佐藤 俊哉, 教授 湊谷 謙司 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Paper A: In this paper, the development and implementation of a contact algorithm based on C2-continuous surface representations is discussed. In 3D contact simulations involving models with arbitrarily curved surfaces (as in the case of vessel walls), the discretization of the contact surfaces by means of facet-based techniques could lead to numerical instabilities and finally loss of quadratic convergence. These instabilities arise mainly due to the sliding of contractor (slave) nodes over the boundaries of target (master) contact facets, where jumps of the normal vector are experienced. The paper addresses successfully this problem, by discretization of the target surfaces by means of C2-continuous parameterization schemes. Initially, the uniform cubic B-spline surfaces are introduced. Next, in an attempt for more accurate representations of the geometric models of the contact surfaces, a new parameterization based on the expression of cubic B-splines is developed. The two approaches are implemented into a finite element framework and more specifically, into the multipurpose finite element analysis program FEAP. The special merits of the developed algorithms and the advantages of the smooth surfaces over facet-based approaches are exhibited through a classical contact mechanics problem, considering incompressibility, finite deformations and large slidings. Next, a simulation of balloon angioplasty with stenting is presented, where the contact between both medical devices (balloon and stent) with the arterial wall is modeled. The arterial wall is modeled in this first approach, as hyperelastic, homogeneous, isotropic, while a cylindrically orthotropic model is developed to capture the nonlinear, anisotropic behavior of the balloon catheter under pressure. Two stents with the same geometry but different strut thickness, are studied. Both are considered elasto-plastic. The performed simulations point out the outcome of the balloon angioplasty and stenting in terms of luminal gain and mechanical strains. Finally, a comparison between the two stent configurations is presented. Paper B: The second paper makes use of the contact tool developed in Paper A and focuses on the changes of the mechanical environment of the arterial wall due to stenting, as a function of a set of stent design parameters. In particular, Paper B presents a detailed geometric and material model of a postmortem human iliac artery, composed by distinct tissue components, each associated with specific mechanical properties. The constitutive formulation for the artery considers anisotropic, highly nonlinear mechanical characteristics under supraphysiological loadings. The material and structural parameters of the arterial model are obtained through uniaxial tensile tests on stripes extracted from the several arterial tissues that form the stenosis, axially and circumferentially oriented. Through cooperation with a well-established stent manufacturing company, an iliac stent was acquired. The dimensions of the stent are measured under a reflected-light microscope, while it is parameterized in such a way as to enable new designs to be simply generated through variations of its geometric parameters. The 3D balloon-stent-artery interaction is simulated by making use of the smooth contact surfaces with C2-continuity, as previously mentioned. Next, scalar quantities attempt to characterize the arterial wall changes after stenting, in form of contact forces induced by the stent struts, stresses within the individual components and luminal change. These numerically derived quantities allow the determination of the most appropriate stent configuration for an individual stenosis. Therefore, the proposed methodology has the potential to provide a scientific basis for optimizing treatment procedures, stent material and geometries on a patient-specific level. / <p>QC 20101118</p>

To assess the technical success rate, and evaluate the clinical outcome, length of hospital stay, and cost of palliative gastro-duodenal stenting in a single-centre. Materials and methods Eight-seven patients referred for insertion of a gastroduodenal stent between April 1999 and April 2004 were recruited to a non-randomized, before and after intervention study performed in a single centre. Demographic data, diagnosis and symptoms along with clinical and technical outcomes were recorded. Results The technical success rate was 84/87 (96.6%), with inability to traverse the stricture in three patients. No immediate complications were demonstrated. There was marked improvement after stent placement with resolution of symptoms and commencement of dietary intake in 76 patients (87%). Stenting resulted in improved quality of life as reflected by an increase in Karnofsky score from 44/100, to 63/100 post-procedure. Late complications included perforation (n=1), migration (n=1) and stent occlusions due to tumour ingrowth/overgrowth (n=7; mean 165 days). Mean survival was 107 days (range 0¿411 days). Median hospital stay post-stent placement was 5.5 days, (range 1¿55 days) with a majority of patients (75%) discharged home. The mean cost of each treatment episode was £4146 ($7132 $US, ¿6,028 EUROS). Conclusion The present series confirms that combined endoscopic and radiological gastroduodenal stenting is a highly favourable treatment for patients with inoperable malignant gastric outlet obstruction. The results suggest that this minimally invasive procedure has a very high technical success rate, whilst at the same time providing excellent palliation of symptoms with improved quality of life in the majority of patients.

Die ERC ist der diagnostisch Goldstandard bei Patienten mit Klatskintumor und kann auch zur palliativen Stenttherapie eingesetzt werden. Wir konnten die Morbidität und Mortalität der post-ERC-Cholangitis bei Patienten mit Klatskintumor deutlich reduzieren, in dem wir nach MRCP-gestützter Bestimmung des Drainageziels nur eine unilaterale Kontrastierung und Stenteinlage durchführten. Die DNA-Zytometrie war der beste Prognosefaktore für das postoperative Überleben von resezierten Patienten mit Klatskintumor. Im Gegensatz zu diploiden und polyploiden Klatskintumoren hatten Patienten mit aneuploiden Tumoren trotz kurativer Resektion eine sehr schlechte Prognose infolge früher Mikrometastasierung. Bei einigen Patienten mit Klatskintumor liegt eine Billroth II-Gastro-Jejunostomie vor. Trotz der erschwerten Endokoppassage gelang es uns meistens, sowohl die Majorpapille zu erreichen, als auch trotz der inversen Endoskopposition eine sichere Papillotomie durchzuführen. Die perkutane Drainagetherapie mittels PTCD ist eine wertvolle Alternative zur transpapillären Stenttherapie. Als kurative Therapie bei nicht-resezierbaren Cholangiokarzinomen werden Lebertransplantationen durchgeführt. Damit assoziierte biliäre Komplikationen konnten bei uns in den meisten Fällen erfolgreich durch endoskopische Therapie behandelt werden. / ERC is considered as the diagnostic gold standard for patients with Klatskin tumor and can be also used for palliative stenting. We could reduce morbidity as well as mortality due to post-ERC-cholangitis performing MRCP-guided identification of the drainage target and subsequently unilateral contrasting and stenting. DNA-cytomtery was the best prognostic factor predicting the postoperative survival propability of patients with cholangiocarinoma. In contrast to patients resected due to diploid or polyploid Klatskin tumors patients with aneuploid tumors suffered from a bad prognosis due to early micrometastasis. Some patients afflicted from Klatskin tumors have a Billroth II gastro-jejunostomy. In spite of the more difficult endoscopic passage we were mostly able to advance the endoscope to the major papille and to perform a save papillotomy. The percutaneous drainage therapy by means of PTCD is an important alternative to transpapillary stenting. Liver transplantation is performed to cure patients with unresectable Klatskin tumor. Biliary complications which occur after transplantations can be successfully treated in most cases by means of endoscopic therapy.

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...

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.

Stenting remains a common treatment option for atherosclerotic arteries. The main drawback of early stent platforms was restenosis, which has been combated by drug eluting stents; however, these stents have suffered from a higher incidence of late stage thrombosis. To address current stenting limitations, the major research focuses have been the development of the next generation of drug eluting stents and first generation bioabsorbable stents. The main objective of this dissertation was the design and development of a new class of bioabsorbable stent composed of elastin mimetic protein polymers. The first phase explored different stent design schemes and fabrication strategies. Successfully fabricated stents were then mechanically tested to ensure they possessed sufficient mechanical strength. Additionally, described herein is the potential to modulate the properties of the elastin mimetics through different crosslinking strategies. We have demonstrated that chemical crosslinking allows for the tailoring of the physical, mechanical, drug delivery, and endothelialization properties of these materials. The potential for drug delivery from this elastin mimetic stent was benchmarked as was the potential to endothelialize these stents. Furthermore, we developed the necessary delivery systems to allow for deployment in the rat aorta model.