Wuppertal, Universiẗat, Diss., 2002.

Orientador: Winston Bonetti Yoshida / Resumo: Objetivo. A presente revisão se propõe a comparar a eficácia e segurança da angioplastia com stent versus angioplastia percutânea transluminal nas lesões sequenciais através dos desfechos: taxa de abertura do vaso (TICI 2b/3), evolução neurológica (mRs < 2) e taxa de hemorragia sintomática (hematoma grau II). Método. Utilizando como base de dados o PubMed, Scopus, Embase, SciELO/LILACS e outros, a presente revisão sistemática foi realizada até setembro de 2017 com base no PICO: (P) Pacientes com oclusão sequencial da carótida na fase aguda do AVCi tratados ou não com fibrinolítico endovenoso, (I) Angioplastia com stent, (C) Angioplastia percutânea transluminal, (O) TICI, mRs e hemorragia sintomática. As seguintes palavras chaves foram utilizadas: Stroke, Carotid Artery Injuries, Angioplasty, Stent and Safety. Aos artigos encontrados, os critérios de seleção do PRISMA foram aplicados, sendo realizada a análise qualitativa através do cheklist do NIH for before-after studies with no control group e a análise quantitativa através do programa Statdirect. Resultados. Identificados 228 artigos que após ajustes e exclusões restaram 29 para a análise qualitativa e quantitativa. TICI após CAS 0,76 (95% CI = 0,72 a 0,79); I2 = 36,9% versus PTA 0,71 (95% CI = 0,61 a 0,81); I2= 28,5%. mRs < 2 em 90 dias após CAS 0,47 (95% CI = 0,43 a 0,51) ); I2 = 3% versus PTA de 0,46 (95% CI = 0,36 a 0,57) ); I2 = 18,7%. Taxa de hemorragia sintomática após CAS 0,08 (95% CI = 0,06 a 0,10); I2 = 5,3%) ver... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Objective: Compare carotid angioplasty and stent (CAS) versus percutaneous transluminal angioplasty (PTA) measuring the efficacy and safety through Thrombolysis in Cerebral Infarction scale (TICI 2b/3), modified Rankin scale (mRs <2) and symptomatic haematoma (PH2). Method: Using the PubMed and others database, we searched for articles publish until setember 2017. The PRISMA criteria was used and rigorous eligibility were applied. The article quality was assessed by a checklist of “Quality Assessment Tool for Before-After (Pre-Post) Studies With No Control Group published" by NIH and proportional meta-analysis was performed by Statdirect software. Results: 228 articles were identified from the databases, after adjustments due to duplicates and submitted to the eligibility criteria, 29 articles with 1339 patients remained for the qualitative and quantitative analysis. TICI 2b/3 value after CAS was 0,76 (95% CI = 0,72 to 0,79); I2 = 36,9% versus PTA 0.71 (95% CI = 0.61 to 0.81); I2= 28,5%, mRs < 2 in 90 days after CAS 0.47 (95% CI = 0.43 to 0.51) ); I2 = 3% versus PTA 0.46 (95% CI = 0.36 to 0.57) ); I2 = 18,7% and symptomatic haematoma 0,08 (95% CI = 0,06 to 0,10) ); I2 = 5,3% versus PTA 0,06 (95% CI = 0,02 to 0,13); I2 = 35,5% showed no statistical difference. Other analyses of subgroups were done, including the effect of tPA with antiplatelet drugs. Conclusion: CAS is effective and safe when compared to PTA in the outcomes TICI 2b/3, mRs < 2 and PH2. A randomized clinical ass... (Complete abstract click electronic access below) / Doutor

Cardiovascular diseases which include high blood pressure, coronary heart diseases, heart failure, stroke and peripheral arterial diseases (PAD) affect one out of three American adults or 105 million people. By 2030, the prevalence of cardiovascular disease is estimated to rise 10 percent to more than 40 percent of American adults, or 116 million people. Approximately 8 million people in the United States have PAD, including 12-20% of individuals older than age 60. The main reason of PAD is obstruction of blood flow through lower extremities causing Atherosclerosis. The major artery affected in the lower extremities due to PAD is superficial femoral artery (SFA). Huge numbers of clinical procedures like superficial femoral artery stenting, balloon angioplasty, and percutaneous transluminal intervention are done to treat the disease. Thorough in vitro (biological phenomena made to occur outside the human body) testing of this kind should reduce the risk of in vivo (biological phenomena occurring inside the human body) stent failure and thus lead to increased survivability for patients suffering with cardiovascular diseases and PAD. It has been recognized that a metal subjected to a repetitive or fluctuating stress will fail at a stress much lower than that required to cause failure on a single application of load. As per literature review, typically SFA stents survive no more than 12-18 months until the first fracture is detected in MRI. There was a need of a customized designed device such that it would simulate realistic blood pressure conditions and test the capacity the SFA stents. Commercially, the stents are tested under accelerated cyclic loading conditions at different frequencies for longer cycle periods. In order to demonstrate how stents perform once deployed into an artery, a testing device was required which will simulate arterial blood pressure variations and compressive loads over artery as close as possible to human body. The stent tester documented in this report is capable of subjecting a stent to appropriate physiological loading by deploying it in a simulated vessel and subjecting it to external compression. Loading of this kind was performed at frequencies at 60 Hz and, as such, simulating one million heartbeats of artery pulsation. The primary purpose of this thesis was to successfully design stent tester which cycles artificial fluid simulating blood pressure in arteries and superimposing cyclic compression of stent deployed in an artificial artery. The goal was to obtain a test machine that allows for a cost effective testing of cardiovascular and peripheral stents. Another goal was to externally compress the arterial wall subjected to compressive load with the help of an air controlled mechanical piston attached with load cell assembly. The load cell measures the amount of load applied over the silicone tubing. The design of the device contains two peristaltic pumps which alternate pressure every second by pumping distilled water via plastic tubing. The stent was crimped with the guide wire catheter and deployed in the silicone artery (diameter 11mm O.D) from Dynatek labs. Wall and bridge stents (Medtronic, Schneider Inc.) 10 x 39 mm were used for testing with and without external load. Industrial pressure transducer S-10 (Wika Instruments Corporation) ranging from 0-5 PSI (0-259mmHg) is used to monitor the pressure in the artificial artery. The pressure transducer is connected to the data logger (Omega om320) which serially communicates with computer. The silicon mock test artery was 20cm long so that stents used in various arterial interventions can be tested. The silicon artery has primary advantages over rubber latex artery which are clarity and close resemblance to human artery and durable (ideal for long term durability tests). Preliminary results from literature review show that stent materials, based on its mechanical properties survive for more than one million heartbeats. To demonstrate the capacity of current design a nitinol stent was tested under physiological conditions at 60Hz frequency. A load of 980 grams for 2001 - 5000 heartbeats, 1.98 kg for 5001 - 10000 heartbeats, 4.25 kg for 10001 - 25000 heartbeats and 6.54 kg for 25001 - 50000 heartbeats was applied over the artificial artery. The mechanical piston with load cell assembly was allowed to externally compress the artificial artery. Partial functionality of device was demonstrated by running it for one million heartbeats and 48000 compressive cycles. The device was successfully designed and has the capacity to cycle artificial fluid simulating blood pressure changes in arteries and have demonstrated the ability to test any type of stents. The device was designed efficient which was simulated in an acceptable pressure range as compared to human blood pressure and allow for compression of stent in a cyclic testing pattern. The system was maintained to as close as between diastolic value of 76mmHg to diastolic 122mmHg pressure range. The device was run for about one million heartbeats and it was observed that the NiTi stent successfully survived. The stent was observed visually with a magnifying glass for any cracks or failure at intervals of 500, 1000, 2000, 5000, 10000, 25000, 50000 and one million heartbeats respectively. After running the device for one week at a frequency of 60Hz, no fractures on the stent were visually observed. However, the stent was deformed from the center. Data analysis showed that the mean diastolic and systolic pressure measurements for intervals with no load were found to be statistically significant i.e. in acceptable range. However, the device design lacks stability due to various reasons like device operates in an open looped system, has bubbles in the artificial artery which might be producing varying pressure values and variation in applying load. The device was partly unable to simulate arterial blood pressure changes under no loading conditions. Efforts are being made to improve the design of the device to make it realistic simulation of variation in arterial blood pressure for long term durable testing of the stents.

Orientador: Silvana Artioli Schellini / Abstract: Objective: To determine if stents increase the success rate of endoscopic dacryocystorhinostomy (DCR-EN) Method: Systematic review of randomized clinical trials of DCR-EN, comparing surgeries performed with and without stents in children older than 10 years of age and adult patients, with primary lacrimo-nasal duct (LND) obstruction. The outcomes were LND patency and adverse events (complications). We searched the databases of Web of Science, Scopus, Embase, Cochrane, PubMed, Lilacs until May 2018. The RevMan 5.3 software provided by the Cochrane Collaboration was used for meta-analysis. Results: Ten studies involving 887 surgeries were included. Five studies were conducted in India, and each of the others were conducted in Canada, Turkey, Saudi Arabia, China and Finland. Lacrimo-nasal duct patency meta-analysis showed stents did not interfere in the chance of success in relation to non-use of the stents to obtain lacrimal viability (OR 1.62, 95% CI 1.00 to 2.64, I2 = 0%). It was not possible to perform a meta-analysis regarding the adverse effects and a descriptive analysis was made of the general complications and complications due to the stents. Conclusion: The use or no of stents in DCR-EN probably does not make any difference in the NLD patency. Further studies may better define whether there is a trend toward a better success rate with the use of stent. Key words: dacryocystorhinotomy, endoscopic, stent, success, meta-analysis / Resumo: Objetivo: Definir se o uso de stents aumenta a taxa de sucesso da dacriocistorrinostomia endoscópica (DCR-EN). Método: Revisão sistemática de ensaios clínicos randomizados referentes a DCR-EN, comparando as cirurgias realizadas com e sem uso de stents em crianças acima dos 10 anos de idade e adultos, com obstrução adquirida do ducto lacrimo-nasal (DLN). Os desfechos avaliados foram a patência do DLN e os eventos adversos (complicações). Foram pesquisadas as bases de dados: Web of Science, Scopus, Embase, Cochrane, PubMed, Lilacs até maio de 2018. Utilizou-se para metanálise o software RevMan 5.3 fornecido pela Colaboração Cochrane. Resultados: Dez estudos envolvendo 887 cirurgias foram incluidos. Cinco estudos foram realizados na India, um em cada um dos países a seguir: Canada, Turquia, Arabia Saudita, China e Finlândia. A metanálise da patência do DLN mostrou que os stents não interferiram na chance de sucesso em relação ao não uso dos stents para a obtenção de permeabilidade da via lacrimal (OR 1,62, IC 95% 1.00 a 2.64; I2 = 0%). Quanto aos efeitos adversos não foi possível realizar metanálise, tendo sido feita análise descritiva das complicações gerais e complicações dos stents. Conclusão: O uso ou não de stents na DCR-EN provavelmente faz pouca ou nenhuma diferença na patência do DLN. Novos estudos poderão melhor definir se há tendência de melhor taxa de sucesso com o uso de stents. / Mestre

The detection of in-stent restenosis is important in clinical practice by providing useful information to guide therapy. The objectives of this study were to evaluate the effectiveness of the exercise test (ET) in the detection of restenosis after percutaneous transluminal coronary angioplasty with stent conventional implantation (Stent-ATC) and, as a gold standard, coronary angiography. We studied 25 asymptomatic patients, aged between 44 and 83 years, who underwent PTCA-Stent for at least six months. The patients underwent TE employing the Bruce protocol. The positivity criteria for ischemia was ST segment depression > 1mm, measured at the J point and with horizontal or descending. The results obtained in TE were compared with those of coronary angiography is considered the in-stent restenosis lesions with obstruction > 50%. We estimated the sensitivity and specificity and positive predictive value and negative procedure. Of the individuals studied, 10 (40%) had in-stent restenosis by angiographic criteria, and only 3 (12%) had positive TST tests for ischemia. The relationship between the TE and coronary angiography was not significant (p = 0.315), indicating that the tests are independent. The concordance between the diagnoses was low (Kappa coefficient: 0.151), the same occurring with the sensitivity (20%). The specificity of the test was high (93%) and positive predictive value 65.56% and negative predictive value 63.63%. The overall efficiency of the test is estimated with accuracy low 63.98%. We conclude that the TE has low sensitivity and high specificity in detecting in-stent restenosis in asymptomatic patients. The overall efficiency of ET is low. / A detecção da reestenose intrastent é importante na prática clínica fornecendo informações úteis para a orientação terapêutica. Os objetivos deste estudo foram, avaliar a eficácia do teste ergométrico (TE) na detecção de reestenose após angioplastia transluminal coronariana com implante de stent convencional (ATC-stent), comparando este método com os resultados obtidos com a cineangiocoronariografia. Foram estudados 25 pacientes assintomáticos, com idade entre 44 e 83 anos, que realizaram ATC-stent há, no mínimo, seis meses e no máximo um ano. Os pacientes foram submetidos ao TE empregando-se o protocolo de Bruce. O critério de positividade para isquemia foi o infra-desnivelamento do segmento ST > 1mm, aferido no ponto J e com morfologia horizontal ou descendente. Os resultados obtidos no TE foram comparados com aqueles da cineangiocoronariografia sendo considerada como reestenose intrastent a presença de lesões com obstrução >50%. Foram estimadas a sensibilidade e especificidade e o valor preditivo positivo e negativo do procedimento. Dos indivíduos estudados, 10 (40%) apresentaram reestenose intrastent pelo critério angiográfico e apenas 3 (12%) tiveram TE positivo para isquemia. A relação entre o TE e a cineangiocoronariografia não foi significativa (p=0,315), indicando que os testes são independentes. A concordância entre os diagnósticos foi baixa (coeficiente Kappa: 0,151), o mesmo ocorrendo com a sensibilidade (20%). A especificidade do TE foi elevada (93%), sendo o valor preditivo positivo 65,56% e o valor preditivo negativo 63,63%. A eficiência global do teste é baixa com acurácia estimada em 63,98%. Em conclusão, nas condições estudadas o TE tem baixa sensibilidade e alta especificidade na detecção de reestenose intrastent em pacientes assintomáticos. A eficiência global do TE é baixa. / Mestre em Ciências da Saúde

Duas técnicas invasivas para o tratamento da doença aterosclerótica coronariana oclusiva firmaram-se ao longo dos anos: revascularização cirúrgica do miocárdio e angioplastia transcutânea com stents metálicos. O estudo visa comparar as alterações histopatológicas causadas por stents metálicos coronarianos fabricados com a superliga de composição química em porcentagem em peso cromo 20%, tungstênio 15%, níquel 10% e cobalto restante, designada ASTM F.90, revestidos, ou não, com carbeto de silício pelo processo de asperção térmica originando uma superfície hidrofílica. Stents com espessura das hastes entre 80 a 90 nm, área das células entre 1,4 a 2,1 mm² e relação metal-artéria de 13 a 19%, em pacientes reestenosantes que sofreram posteriormente revascularização cirúrgica do miocárdio, com aqueles não submetidos à angioplastia prévia. Foram determinados dois grupos: grupo I ou grupo controle, pacientes que sofreram revascularização cirúrgica do miocárdio sem angioplastia prévia de qualquer natureza; grupo II pacientes submetidos à revascularização cirúrgica do miocárdio, após reestenose intra-stent coronariana. Pacientes de ambos os grupos foram avaliados rotineiramente quanto à indicação e risco cirúrgico e durante o procedimento convencional da revascularização cirúrgica do miocárdio utilizando circulação extracorpórea, antes de realizar a anastomose do enxerto vascular na coronária, amostras contendo pequenos fragmentos de endotélio foram retiradas juntamente com fragmentos dos stents, enviadas para análise histopatológica e produção de laminas coradas com H-E. Observou-se a presença de arterite crônica caracterizada por infiltrado mononuclear em conjunto com fenômeno de proliferação fibroblástica e de musculatura lisa naqueles pacientes que apresentavam reestenose intra-stent, sendo mais intenso no local do stent. A visualização das superfícies dos stents em escala nanometrica (MFA) é de suma importância para análise estrutural das próteses, avaliando irregularidades nas superfícies recobertas das hastes dos stents. A persistência de arterite crônica coronariana avaliada por infiltrado linfomononuclear e proliferação de fibrocolágeno foi constatada em pacientes reestenosantes. / Two invasive techniques for the treatment of occlusive coronary atherosclerosis disease were signed over the years: coronary artery bypass surgery and transcutaneous angioplasty with bare metal stent. The study attempts to compare the histopathological abnormality caused in patients with implantation of bare metal stent in coronary made with: Chromium 20%, Tungsten 15%, Nickel 10% and Cobalt remainder, ASTM F.90 alloy for surgical implant applications, and covered with a thin layer of amorphous silicon carbide, or not, and its total or partial obstruction, after undergoing coronary artery bypass grafting, with those who had coronary artery bypass surgery with no previous angioplasty. Two groups were studied: group I, or control group, patients who underwent coronary artery bypass grafting without previous angioplasty of any kind; group II of patients undergoing coronary artery bypass surgery after coronary-stent restenosis. Patients in both groups were evaluated for the indication and surgical risk; was done routinely during the procedure of conventional coronary artery bypass grafting with cardiopulmonary bypass. Before performing the anastomosis in coronary vascular graft, a small fragment of the endothelium was removed along whit a fragment of the stent, and sent for analysis with hematoxilin-eosin. The presence of chronic inflammatory coronary reaction was detected, mediated by mononuclear cells with phenomenon of fibroblast and smooth muscle proliferation in patients presenting in-stent restenosis. It w coronary reaction as also observed that the inflammatory and proliferative process is more intense at the site of stent implantation. The analysis of surface of the stents used atomic force microscopy proved to be an important method for the surface analysis for stents, and showed on nanometric scale an irregular coverage of silicon carbide. In conclusion, in the patients with restenosis in-stent occurs persistence of chronic inflammation with mononuclear cells and process of fibroblast proliferation.

L’occlusion colique est le mode de révélation de 8 à 29% des cancers du colon. Elle révèle undiagnostic tardif associé le plus souvent à une tumeur localement avancée ou métastatique. Laprise en charge, en urgence, de ces cancers est donc cruciale et doit intégrer l’évaluation del’état général du patient (âge, comorbidités, état nutritionnel), et le stade de la maladie quiauront un impact direct sur les résultats postopératoires précoces et à distance. Les optionsthérapeutiques disponibles pour la prise en charge en urgence de ces tumeurs sontchirurgicales (colostomie de décharge, intervention de Hartmann, colectomie segmentaireavec ou sans lavage per opératoire avec anastomose colorectale, colectomie totale avecanastomose iléorectale) ou endoscopique (prothèse colique).Les objectifs de cette thèse étaient d’évaluer l’impact de la prothèse colique sur la prise encharge à visée curative des cancers coliques en occlusion, l’étude des donnéesanatomopathologiques afin d’expliquer les différences de survie en fonction de la stratégiethérapeutique et l’élaboration de recommandations françaises et européennes afin de préciserla place de la prothèse colique dans la prise en charge des cancers coliques en occlusion / The colonic obstruction is the mode of revelation of 8 to 29% of colon cancers. It reveals latediagnosis most often associated with a tumor locally advanced or metastatic disease. Themanagement, in an emergency, of these cancers is crucial and must include the evaluation ofthe patient's general condition (age, comorbidities, nutritional status), and the stage of thedisease that will have a direct impact on early and late postoperative outcomes. Treatmentoptions available totreat in emergency these tumors are surgical (colostomy, Hartmannprocedure, segmental colectomy with or without intraoperative lavage with colorectalanastomosis, total colectomy with ileorectal anastomosis) or endoscopic (colonic stent).The objectives of this thesis were to assess the impact of the colonic stent in the curativemanagement of obstructive colonic cancer, to study pathological data to explain differences insurvival according to treatment strategy and the development of French and Europeanrecommendations to clarify the role of colonic stent in the treatment of colon cancerocclusion

It is projected that by 2020, there will be 138 million Americans over 45, the age at which the increased incidence of heart diseases is documented. Many will require stents. This multi-billion dollar industry, with over 2 million patients worldwide, 15% of whom use Nitinol stents have experienced a decline in sales recently, due in part to thrombosis. It is a sudden blood clot that forms inside stents. As a result, the Food and Drug Administration and American Heart Association are calling for a new generation of stents, new designs and different alloys that are more adaptable to the arteries. The future of Nitinol therefore depends on a better understanding of the mechanisms by which Nitinol surfaces can be rendered stable and inert. In this investigation, binary and ternary Nitinol alloys were prepared and subjected to various surface treatments such as electropolishing (EP), magnetoelectropolishing (MEP) and water boiling & passivation (W&P). In vitro corrosion tests were conducted on Nitinol alloys in accordance with ASTM F 2129-08. The metal ions released into the electrolyte during corrosion tests were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Biocompatibility was assessed by observing the growth of human umbilical vein endothelial cells (HUVEC) on the surface of Nitinol alloys. Static and dynamic immersion tests were performed by immersing the Nitinol alloys in cell culture media and measuring the amount of metal ions released in solution. Sulforhodamine B (SRB) assays were performed to elucidate the effect of metal ions on the growth of HUVEC cells. The surfaces of the alloys were studied using Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) respectively. Finally, wettability and surface energy were measured by Contact Angle Meter, whereas surface roughness was measured by Atomic Force Microscopy (AFM). All the surface treated alloys exhibited high resistance to corrosion when compared with untreated alloys. SRB assays revealed that Ni and Cu ions exhibited greater toxicity than Cr, Ta and Ti ions on HUVEC cells. EP and MEP alloys possessed relatively smooth surfaces and some were composed of nickel oxides instead of elemental nickel as determined by XPS. MEP exhibited lowest surface energy and lowest surface roughness.

This PhD thesis reports an investigation into medical coronary stent cutting using three different types of lasers and associated physical phenomena. This study is motivated by a gap in the current knowledge in stent cutting identified in an extensive literature review. Although lasers are widely used for stent cutting, in general the laser technology employed is still traditionally based on millisecond pulsed Nd:YAG lasers. Although recent studies have demonstrated the use of fibre lasers, picosecond and femtosecond lasers for stent cutting, it has been preliminary studies.To further understand the role of new types of lasers such as pulsed fibre lasers, picosecond and femtosecond pulsed lasers in stent cutting, these three lasers based stent cutting were investigated in this project. The first investigation was on a new cutting method using water assisted pulsed (millisecond) fibre laser cutting of stainless steel 316L tubes to explore the advantages of the presence of water compared to the dry cutting condition. Significant improvements were observed with the presence of water; narrower kerf width, lower surface roughness, less dross attachment, absence of backwall damage and smaller heat affected zone (HAZ). This technique is now fully commercialised by Swisstec, an industrial project partner that manufactures stent cutting machines.The second investigation used the picosecond laser (with 6 ps pulse duration in the UV wavelength range) for cutting nickel titanium alloy (nitinol) and platinum iridium alloy. The main achievement in this study was obtaining dross-free cut as well as clean backwall, which may eliminate the need for extensive post-processing. Picosecond laser cutting of stents is investigated and reported for the first time. The third area of investigation was on the use of a femtosecond laser at 100 fs pulse duration for cutting nickel titanium alloy tubes. It was found that dry cutting degraded the cut quality due to debris and recast formation. For improvement, a water assisted cutting technique was undertaken, for the first time, by submerging the workpiece in a thin layer of water for comparison with the dry cutting condition. The final part of the thesis presents a three dimensional numerical model of the laser micromachining process using smoothed particle hydrodynamics (SPH). The model was used to provide better understanding of the laser beam and material interaction (with static beam) including the penetration depth achieved, phase changes, melt ejection velocity, also recast and spatter formation. Importantly, the model also simulated the wet machining condition by understanding the role of water removing the melt ejected during the process which avoided backwall damages. Results with the fibre laser in millisecond pulse duration were used for the validation purposes. The conclusions reached in this project and recommendations for future work are enclosed.The work has resulted in the publication of 3 journal papers and 2 additional journal paper submissions.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22339号 / 医博第4580号 / 新制||医||1042(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 木村 剛, 教授 髙橋 良輔, 教授 小池 薫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM