• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 212
  • 84
  • 16
  • 10
  • 6
  • 6
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 361
  • 361
  • 191
  • 189
  • 106
  • 85
  • 83
  • 52
  • 46
  • 45
  • 45
  • 44
  • 43
  • 42
  • 37
  • 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.
91

Prognóstico em portadores de insuficiência cardíaca encaminhados para avaliação de tratamento cirúrgico / Prognosis in outpatients with heart failure referred to surgical treatment

Humberto Felício Gonçalves de Freitas 03 July 2002 (has links)
O objetivo deste estudo foi avaliar o prognostico de portadores de insuficiência cardíacadoe diferentes etiologias, incluindo a Doença de Chagas, na década de noventa ern uma unica intituição. Foram avaliados 1 220 pacientes portadores de insuficiência cardíaca encaminhados para avaliação de tratamento cirúrgico, acompanhados por período de 25,6+- 26 meses. As idades variavarn entre 13 e 72 anos (45,5 +- 11 anos); 952 (78%) pacientes eram do sexo masculino e 268 (22%) do feminino.A insuficiência cardíaca foi considerada idiopática em 454 (37,2%) doentes. A etiologia da insuficiência cardiaca foi a Doença de Chagas em 242 (19,8%) pacientes, a isquemia em 121 (17,4%) a hipertensiva em 170 (13,9%) e outras etiologias em 142 (11,7%). O tratamento medicamentoso padrão incluiu os inibidordes da enzimaa conversora da anqiotensma. Depois da análise exploratória Inicial, foi realizada análise de sobrevivência, pelo método de Kaplan Meier para cada variável clínica observada. Em seguida, realizaram-se análises dos riscos proporcionais pelo método de Regressão de Cox univariada e multivariada para avaliar o proqnostico por meio de variáveis clínicas não invasivas por meio de variáveis clínicas não invasivas (modelo não invasivo) e variáveis obtidas do cateterismo cardíaco direito (modelo invasivo). Quatrocentos e vinte e cinco (34,8%) pacientes morreram na evolução 74 (6,1 %) foram submetidos a transplante cardíaco e 28 (2,3%) foram submetidos a outras intervenções cirúrgicas. Com o emprego do modelo não invasivo, foram identificados a etiologia da Doença de Chagas (risco relativo 2,72), o diâmetro diastólico do ventrículo esquerdo (risco relativo 1,13) e a fração de ejeção do ventrículo esquerdo (risco relativo 0,96), como as variáveis mais importantes relacionadas com o prognóstico. Com o emprego do modelo invasivo foram identificados o índice cardíaco (risco relativo 0,40) e a etiologia da Doença de Chagas (risco relativo 9,13) como as variáveis mais importantes relacionadas com o prognóstico. A Doença de Chagas foi identificada nesta casuística como o principal fator prognóstico em pacientes portadores de insuficiência cardíaca sintomática grave encaminhados para avaliação de tratamento cirúrgico / To evaluate clinical determinants of prognosis in a hospital based series of outpatients with severe failure of differente etiologies, including Chagas\' heart disease, we followed up a large series of patients in the nineties in a Instituition. 1220 outpatients referred for treatment of heart failure in a tertiary care university hospital dedicated to cardiology were followed-up for 25.6 +- months. The ages of the patients ranged between 13 and 72 (45.5 +- 11) years, 952 (78%) patients were men and and 268 patients (22%) women. Heart failure was attrubuted to indiopathic dilated cardiomyopathy in 454 (37.2%) patients. Etiologies were Chagas\' heart disease in 242 (19.8%) patients, ischemic heart disease in 212 (17.4%) in hypertensive heart disease in 170 (13.9%) and others in 142 (11.7% ). Therapy included anqiotensin converting enzimy inhibitors titrated to the patients\' needs and standard therapy to heart failure. The probability of survival of the patients was assessed through Kaplan Meier method for each clinical variable. Subsequently, an univariate Cox proportional hazard was fitted and multivariate analysis was performed for evaluating prognosis, through pooled non-invasive clinical variables (invasive model). 425 (34.8%) patients died in the follow-up, 74 (6.1%) patients underwent heart transplantation and 28 (2.3%) underwent other surgical interventions. Through the non-invasive model Chagas\' heart disease etiology (relative risk 2.72), left ventricular injection fraction (relative risk 0.96) were identified as the leading determinants of prognosis. Through the invasive model Chagas heart etiology (relative risk of 9.13) and the cardiac index (relative risk 0.40) identified as the most important determinants of prognosis. Chagas disease etiology of heart failure referred to surgical treatment.
92

Avaliação clínica do tratamento cirúrgico e não-cirúrgico de pacientes com periodontite agressiva / Clinical evaluation of surgical and nonsurgical treatment of patients with aggressive periodontitis

Cirino, Camila Camarinha da Silva, 1986- 22 August 2018 (has links)
Orientador: Antônio Wilson Sallum / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T19:02:53Z (GMT). No. of bitstreams: 1 Cirino_CamilaCamarinhadaSilva_M.pdf: 1347661 bytes, checksum: 1541e9727de891711daaa2773bd8086f (MD5) Previous issue date: 2013 / Resumo: O presente estudo tem como objetivo avaliar, por meio dos parâmetros clínicos, o efeito das terapias periodontais cirúrgica e não-cirúrgica no tratamento da periodontite agressiva generalizada (PAG). Doze pacientes portadores de periodontite agressiva generalizada foram incluídos neste estudo clínico controlado randomizado com desenho experimental de boca dividida, e foram alocados em dois grupos: Grupo TNC (tratamento não-cirúrgico) - debridamento ultrassônico associado a raspagem manual; e Grupo TC (tratamento cirúrgico) - acesso cirúrgico para debridamento ultrassônico associado a raspagem manual. As avaliações clínicas foram realizadas antes do tratamento (baseline), 3 meses e 6 meses após o mesmo, considerando os seguintes parâmetros: índice de placa (IP), índice de sangramento à sondagem (ISS), profundidade de sondagem (PS), nível de inserção clínico (NIC) e recessão gengival (RG). Ambos os tratamentos promoveram ganho de inserção clínica e redução de profundidade de sondagem para todos os sítios em relação ao baseline, sem diferença estatística entre os grupos. As médias de redução de PS para bolsas moderadas foi de 1,3 mm para o grupo TNC e 1,2 mm para o grupo TC (p=0.79). As médias de ganho de inserção foram também semelhantes, com 1 mm para TNC e 0,8 mm para TC (p=0.44). Nas bolsas profundas, o grupo TNC apresentou 2,2 mm de redução de PS, enquanto o grupo TC apresentou redução de 2,9 mm (p=0.18). Quando NIC foi avaliado, o ganho no grupo TNC foi de 1,6 mm, e o grupo TC apresentou ganho de 2,4 mm (p=0.2). Como consequência de ambas as terapias, houve o surgimento de recessão gengival, com valores semelhantes entre os grupos. Dentro dos limites deste estudo, pode-se concluir que as terapias periodontais cirúrgica e não-cirúrgica foram capazes de promover melhoras clínicas em pacientes com periodontite agressiva generalizada / Abstract: This present study aimed to evaluate, based on clinical parameters, the effect of surgical and non surgical periodontal therapy in treatment of generalized aggressive periodontitis (GAP). Twelve patients with generalized aggressive periodontitis were included in this randomized controlled clinical study with experimental split-mouth design, and were allocated into two groups: NST Group (non surgical treatment) - ultrasonic debridement associated with manual scaling, and ST Group (surgical treatment) - access to surgical ultrasonic debridement associated with scaling manual. Clinical evaluations were performed before treatment (baseline), 3 months and 6 months after treatment, considering the following parameters: plaque index (PI), bleeding on probing index (BOP), probing depth (PD), clinical attachment level (CAL) and gingival recession (GR). Both treatments promoted gain in CAL and reduction in pocket depth for all sites, with no statistical difference between groups. Means of reduction of PD to moderate pockets was 1.3 mm for NST group and 1.2 mm for ST group (p=0.79). Gain of attachment were also similar, with group NST presenting 1 mm and 0.8 mm for group ST (p=0.44). In deep pockets, the NST group showed 2.2 mm of reduction of PD, while ST group decreased 2.9 mm (p=0.18). When CAL was evaluated, the gain in group NST was 1.6 mm, and ST group presented gain of 2.4 mm (p=0.2). The development of gingival recession was observed after both therapies, with similar values among groups. Within the limits of this study, it can conclude that surgical and non-surgical periodontal therapies were able to promote clinical improvements in patients with generalized aggressive periodontitis / Mestrado / Periodontia / Mestra em Clínica Odontológica
93

Incidência de embolia gordurosa pós-cirurgia de lipoaspiração com ou sem lipoenxertia = estudo em animais / Occurrence of fat embolism after liposuction surgery, with or without lipografting : in animal study

Franco, Fernando Fabricio, 1978- 18 August 2018 (has links)
Orientadores: Alfio José Tincani, Luciana Rodrigues de Meirelles / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T22:17:19Z (GMT). No. of bitstreams: 1 Franco_FernandoFabricio_D.pdf: 2115089 bytes, checksum: b74f7a822f16bf0228730d3a2f4ab28a (MD5) Previous issue date: 2011 / Resumo: Introdução: A lipoaspiração é um procedimento cirúrgico que consiste na retirada do excesso de tecido gorduroso localizado, em indivíduos saudáveis. Este procedimento, que muito aumentou nas últimas décadas em todo o mundo, pode ser associado à lipoenxertia. Ambos são empregados para melhora do contorno corporal. Uma das principais complicações relacionadas com a lipoaspiração é a embolia gordurosa. O presente estudo tem por objetivo verificar qualitativamente se existe mobilização intravascular da gordura após lipoaspiração manual pela técnica de infiltração superúmida para pulmões, fígado, rins e cérebro, em ratos da raça Wistar, seguida ou não de lipoenxertia. Método: Utilizou-se 30 modelos animais de ratos da linhagem Wistar. Os animais foram submetidos ao método usual da lipoaspiração e analisados em três diferentes grupos. Todos os animais foram anestesiados e infiltrados no subcutâneo do abdome com soro fisiológico contendo adrenalina, distribuídos da seguinte forma: no grupo A, dez animais serviram de controle, no grupo B, 10 animais foram lipoaspirados na região abdominal e no grupo C outros 10 animais, além de lipoaspirados, foram lipoenxertados na região dorsal inferior. Uma amostra de sangue foi colhida logo após a anestesia e após 48h dos procedimentos em todos os grupos, para gota de esfregaço em lâmina. Esse procedimento analisou os valores da hemoglobina, bem como a oxigenação sanguínea. Todos os animais foram submetidos á eutanásia após 48h, e os pulmões, rins, fígado e cérebro analisados histologicamente por duas colorações diferentes: Hematoxilina e Eosina (H&E) e Sudan Negro. Resultado: Foram encontradas partículas de gordura nos pulmões de três animais do Grupo B que foram apenas lipoaspirados e, em seis animas do grupo C, lipoaspirados e lipoenxertados. Nos animais do grupo controle, não foram identificados à presença de partículas de gordura em nenhum órgão estudado. Conclusão: Este estudo demonstra que há risco de mobilização sistêmica de gordura, após lipoaspiração e este risco aumenta, quando o procedimento está associado à lipoenxertia, em ratos Wistar / Abstract: Introduction: Liposuction is a surgical procedure that consists of the removal of excess fatty tissue found in health subjects. This procedure, which has become increasingly common in recent decades throughout the world, can be associated with fat grafting. Both are employed to improve the body contour. One of the main complications of liposuction is fat embolism. The present study aims to verify whether there is qualitative intravascular mobilization of fat after the employment of the liposuction technique manual super wet infiltration of the lungs, liver, kidneys and brain in Wistar rats followed or not by fat grafting. Method: We used animal models of 30 Wistar rats. The animals were subjected to the usual method of liposuction and analyzed in three different groups. All animals were anesthetized and infiltrated with saline solution containing epinephrine, distributed as follows: Group A, ten animals served as controls, in group B, 10 animals were liposuction in the abdominal region in group C and 10 other animals, and liposuction were in the lower back fat grafting. A blood sample was collected immediately after anesthesia and 48h of procedures in all groups, to drop the smear slide and examine the values of hemoglobin, and blood oxygenation. All animals were euthanized after 48h, and the lungs, kidneys, liver and brains were histologically examined by two different colors: hematoxylin and eosin (H & E) and Sudan Black. Results: There were fat particles in the lungs of three animals in Group B that were only subject to liposuction and six animals in group C, subject to liposuction and fat grafting. Fat particles were not found in any organ studied in the control group. Conclusion: This study demonstrates that there is risk of systemic fat mobilization after liposuction and this risk increases when the procedure is associated with fat grafting in Wistar rats / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências
94

The impact of surgical day care on hospital inpatient utilization in a paediatric population

Elo, Jyrki A. I. January 1987 (has links)
Day care surgical services have been marketed as a cost saving alternative for inpatient care. There is evidence that the cost per episode of day care surgery is 50-70 percent less than a comparable episode in an inpatient ward. In addition, avoiding hospitalization has particular relevance for paediatrics, because of the undesirable effects of hospital stay on children. However, both cost savings and the quality-based need to decrease hospitalizations of children will be fullfilled only if each patient cared for in a day care surgery unit would otherwise have been an inpatient and the bed vacated by day care surgery use would not be filled in by other patients. In a previous B.C. study based on the total population a significant component of day care surgery was found to augment total utilization, suggesting generation of surgical activity rather than substitution. The present study was designed to examine the substitution/generation issue in the paediatric (0-14 years) population, both because experts questioned the generalizability of the findings to the paediatric population, and because of the dramatic reduction in paediatric utilization in Canada during the period since the mid-1960s. The contention was that the introduction of day care surgery may have been an important factor in this downtrend. The relationship between paediatric day care surgery use and hospital inpatient utilization was analyzed in B.C. in each of the years 1968-1976 and 1981/82-1982/83 and using a time series/cross-section study design. The data frame consisted of all B.C. school districts, in each of the study years, yielding 825 data points. Using a multivariate regression analysis, it was possible to estimate what hospital utilization patterns would have been in the absence of day care surgery capacity, and hence isolate estimates of the net impact of day care surgery on paediatric inpatient use. Findings on the relationship between day care surgery use and paediatric medical/surgical and surgical inpatient utilization strongly support the view that paediatric day care surgery has been largely an add-on to the total hospital care system. Statistically significant substitution effect was revealed only for the most narrowly defined inpatient surgery category which more closely resembled day care surgery-type cases, after controlling for potential confounding effects of age and sex, paediatric bed capacity, different socioeconomic characteristics and time- and district-specific factors. Even here, less than 10 percent of day care surgery represented substitution for inpatient surgery and over 90 percent appeared to be generation of new activity to the hospital system as a whole. Furthermore, paediatric beds which were "saved" by day care surgery use were filled with increased utilization by non-day care surgery eligible surgical patients and by medical cases. The main driving force behind hospital utilization in the 0-14 year age group was paediatric bed availability even after standardization for age, sex, physician stock, measures of socioeconomic status, and other district- and year-specific effects. According to this study paediatric day care surgery has not been a cost saving alternative for inpatient care in B.C. in 1968-1982/83. Neither has it reduced overall hospitalizations in the paediatric population. / Medicine, Faculty of / Population and Public Health (SPPH), School of / Graduate
95

Influência da terapia cirúrgica periodontal no controle glicêmico de pacientes diabéticos tipo 2

LUCENA, Keila Cristina Raposo 10 February 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-20T13:01:25Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE FINAL keila.pdf: 532756 bytes, checksum: c49aa0e3efc358990d4c25a3cdffcf32 (MD5) / Made available in DSpace on 2017-07-20T13:01:25Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE FINAL keila.pdf: 532756 bytes, checksum: c49aa0e3efc358990d4c25a3cdffcf32 (MD5) Previous issue date: 2015-02-10 / CNPQ / OBJETIVO:este estudo avaliou os efeitos clínicos e metabólicos, além da avaliação polimórfica da Il-1ß, IL-12 e IL-10, de pacientes com periodontite crônica e diabetes tipo 2, comparando a terapia periodontal convencional e a terapia cirúrgica no tratamento de bolsas residuais nos períodos de 0, 3 e 6 meses. MATERIAL E MÉTODOS:este ensaio clínico randomizado controlado foi conduzido em 30 pacientes com bolsas residuais contralaterais, alocados randomicamente em dois grupos: G1 (n=16) - terapia cirúrgica – e G2 (n=14) – terapia convencional. Os parâmetros clínicos periodontaise metabólicos foram avaliados nos meses 0, 3 e 6. Também foi avaliada a distribuição de genótipos polimórficos das interleucinas IL-1, IL-10 e IL-12. RESULTADOS:houve uma melhora significativa nos níveis de Hb1Ac no G1 quando comparada ao G2 nos meses 3 e 6 (p<0,05). As médias da profundidade de sondagem (PS) e do nível de inserção clínica (NIC) foram reduzidas no G1 no tempo (0-6) (p<0,05) sem diferença estatisticamente significante quando comparado ao G2 nos tempo avaliados. Houve uma redução significativa no G2 quanto ao NIC no tempo (3-6) (p<0,05). Não houve diferença significativa quando avaliada e comparada a distribuição dos polimorfismos no G1 e G2 com os parâmetros clínicos avaliados (p>0,05). CONCLUSAO:a terapia cirúrgica periodontal trouxe melhorias no controle da Hb1Ac de pacientes diabéticos tipo 2 embora quando avaliados os parâmetros clínicos periodontais PS , NIC, as duas modalidades terapêuticas comportaram-se de forma semelhante. A presença de polimorfismos não influenciou a resposta ao tratamento periodontal nos dois grupos estudados. / OBJECTIVES: this study evaluated the effects clinical and metabolic moreover evaluated polimorphisms of IL-1ß, IL-12 and IL-10 inpacients with chronic periodontitis and diabetes type 2 comparing surgical and non surgical therapies on residual pockets over at baseline, 3 and 6 months post-therapy. MATERIAL AND METHODS:this randomized controlled trial was conduzed in 30 subjects presents contralateral residual pockets randomicaly allocated in 2 groups: G1 (n=16) – surgical therapy – and G2 (n=14) – non surgical therapy. Metabolics and periodontal clinical parameters were assessed at baseline, 3 and 6 months post-therapy. Distribution of polymorphic genotypes of IL-1, Il-10 and IL-12 was assessed. RESULTS:there was a significant improvement in Hb1Ac levels in G1 compared to G2 in the months 3 and 6 (p<0,05). The mean number, PD and CAL improved significantly after therapy in G1 (0-6) (p<0,05) without differences between groups at any timepoint(p>0,05).CAL was improved significantlyin G2 ate (3-6) (p<0,05). There was no significant difference when evaluated and compared the distribution of polymorphisms of interleukins in the G1 and G2 with clinical parameters evaluated (p>0,05). CONCLUSION: periodontal surgical therapy improves Hb1Ac levels in diabetics type 2 although when evaluated PD and CALboth therapisbehaved similarly.The presence of polymorphisms did not influence the response to periodontal treatment in both groups.
96

Minimally Invasive Approach to Vascular Compression of The Duodenum

Ahmed, Aws E., Strand, Matthew S., Iannitti, David A. 25 April 2023 (has links)
Complete or partial obstruction of the duodenum by the superior mesenteric artery (SMA) is a rare cause of bowel obstruction. SMA syndrome results from the compression of the 3rd part of the duodenum between the superior mesenteric artery and the abdominal aorta. Causes include anatomical variation in the superior mesenteric artery, trauma, burns, surgeries, malignancy, and rapid weight loss. Diagnosis of SMA syndrome in patients may be difficult, as the clinical findings often resemble other forms of small bowel obstructions. This syndrome was first described in the literature by Carl Freiherr von Rokitansky in 1861. Subsequently, David Wilke provided a comprehensive description of the disease in a series of 75 patients. There has been skepticism about the existence of SMA syndrome due to scant literature reports and non-specific symptomatology. However, modern cross-sectional imaging has confirmed the existence of this rare syndrome. Here we present the case of a 50-year-old female with longstanding symptoms of gastrointestinal discomfort, weight loss, nausea, and vomiting. She underwent an exhaustive gastrointestinal workup until a diagnosis of SMA syndrome was made. We elected to proceed with a minimally invasive three-port laparoscopic, trans-mesenteric side-to-side duodenojejunostomy. The patient was discharged on postoperative day one after tolerating a regular diet. On one month follow-up, our patient reported improvement in symptoms with no postprandial pain or nausea and normal bowel movements. In conclusion, we report a case of superior mesenteric artery syndrome in a patient with recurrent abdominal pain and nausea. CT scan has the highest sensitivity for the diagnosis of SMA syndrome, findings suggestive of the diagnosis include an abnormal aortomesenteric angle and distance. While supplemental tube feeds and gastric drainage may resolve the condition without the need for surgery, this often takes many weeks to months to be effective. Minimally invasive surgical bypass is an attractive option because of the rapidity of symptom resolution, lack of need for long-term invasive tubes, short inpatient length of stay, and high success rate.
97

A simulation system of vascular interventional radiology procedures for training endovascular skills. / 一套训练用的血管介入式手术模拟系统 / CUHK electronic theses & dissertations collection / Yi tao xun lian yong de xue guan jie ru shi shou shu mo ni xi tong

January 2012 (has links)
近年来,血管类疾病已经成为人类健康的第一杀手。每年有成百上千万人死于血管疾病。血管介入术是一种非常有前景的血管类疾病的治疗手段。血管介入术是一种微创手术,它已经被广泛的用于治疗中风,血管狭窄,血管瘤等疾病。相对于传统的开放式手术,它具有风险低,恢复快,住院时间短等优点。该疗法通常在透视影像的引导下由导管和导线在血管内协同完成手术过程。因为介入术的复杂性和特殊性,作为介入手术医生的必要技能,掌握手术中手眼协同,各种手术器具的使用和复杂细致的手术流程无疑是一个巨大的挑战。因此,迫切地需要一种高效、安全的训练系统。相对于传统的训练方法,基于虚拟现实技术的训练系统是一种非常好的训练手段。 / 为了建立一套高仿真的介入手术训练模拟器,首先,我们要为病人的血管网重建三维模型。我们提出了一种自动的提取中心线的方法,用来从分割好的CTA/MRA体数据中获取病人血管网的中心线。基于改进的平行传递算法,沿着这些中心线,生成了一系列连续的标架。根据这些标架,我们构造了血管的横截面,并在此基础上生成了光滑连续的三维血管模型。 / 其次,作为血管介入术中最基础和最重要的手术器械,我们为导管和导线建立了物理模型。我们提出了一种基于最小势能原理的可变形的模型用于模拟导管和导线对于受力的反应。我们还提出了一个快速并且稳定的多网格算法来保证模拟的真实性和严格的实时交互要求。另外,我们做了几组实验。通过这些实验,验证了多网格算法在稳定性、实时性、模拟的真实性等方面满足了我们对于训练用模拟系统的要求。 / 再次,为了模拟血管栓塞术的手术过程,我们提出了一种模拟线圈填充血管瘤的过程的新方法。通过加总线圈弯曲变形的弹性势能、血管瘤变形的弹性势能以及外力做的功,我们建立了在血管栓塞术的环境下的总势能模型。为了求解这个模型,我们提出了一个基于有限元方法的求解器。从而模拟了线圈在介入医生的操作下慢慢的进入血管瘤,并缠绕起来的过程。 / 另外,我们提出了一个分层圆柱网格模型(LCGM)用于模拟在血管网中血流的运动。这一模型在几何上和拓扑结构上都非常适合我们的应用。我们将血液在血管中的流动近似为一维的层流,并用一组线性等式描述了血管网中流速与血压的关系。通过求解这一线性系统,得到了在分层圆柱网格模型下血流的速度场。依据这个血流的速度场,我们采用平流-扩散模型来模拟造影剂在血管中的传播的过程。 / Vascular diseases have been becoming the number one cause of death worldwide in recent years. Millions of people were killed by vascular diseases each year. An increasingly promising therapy for treating vascular diseases is Vascular Interventional Radiology (VIR). VIR is a minimally invasive surgery (MIS) procedure, which has been widely used to cure stroke, angiostenosis, aneurysm and etc. A low risk, an accelerated recovery and a shorter stay in hospital are important advantages over the traditional vascular surgery. This therapy is performed by a guidewire-catheter combination inside the blood vessels under the guidance of the fluoroscopic imaging. Because of the complexity and particularity of these procedures, it is a great challenge to master hand-eye coordination, instrument manipulation and procedure protocols for each radiologist mandatory. An efficient and safe training system is needed urgently. In contrast to these traditional training methods, virtual reality (VR) based simulation systems is a pretty good surrogate. / In order to build a high fidelity interventional simulator for physician training, firstly, we reconstructed the three dimensional (3D) model for the vascular network of the patients. An method of automatic skeleton extraction was proposed to acquire the centerline of the vascular network from the segmented volume data from CTA/MRA. A series of continuing frames were generated along with the centerline based on improved parallel transporting method. According to these frames we built the crossections of the vessels and further the 3D vascular model with the smooth meshes. / Secondly, as the most basic and important instruments in the VIR procedure, the catheter and guidewire were modeled and simulated physically. We developed a deformable model to simulate complicated behaviors of guidewires and catheters based on the principle of minimum total potential energy. A fast and stable multigrid solver was proposed to ensure both realistic simulation and real time interaction. A series of experiments were conducted to evaluate our multigrid solver in terms of stability, time performance, the capability of simulating catheter behaviors and the realism of catheter deformation. / Thirdly, to simulate the procedure of embolization, we proposed a novel method to simulate the motion of coil and their interactions with the aneurysm. We formulated the total potential energy in the embolization circumstance by summing up the elastic energy deriving from the bending of coils, the potential energy due to the deformation of the aneurysm and the work by the external forces. A novel FEM-based approach was proposed to simulate the deformation of coils. And the motion of coils and their responses to every input from the interventional radiologist can be calculated globally. / Fourthly, we proposed our Layered Cylindrical Gird Model (LCGM) for simulating blood flow in vascular network, which is pretty suitable for sampling the vascular network geometrically and topologically. The blood flow in vessels was regarded as 1D laminar flow and formulated into a set of linear equations based on the Poiseuille law to describe the relationship between the speed of flow and the pressure. Solving those equations, we got the velocity fields in the blood flow. In terms of the velocity fields, an advection-diffusion model was adopted to simulate the propagation of contrast agent with the blood flow. / Finally, all above techniques and procedures were implemented and integrated into a simulation system for training the medical students to acquire the endovascular skill, and an empirical study was also designed based on a typical selective catheteriza- tion procedure to assess the feasibility and effectiveness of the proposed system. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / 最后,我们将所有以上提到的技术和方法集成到模拟系统中用于训练医学院的学生,并使他们获得血管介入术的技能。并且,我们基于一个典型的导管插入术过程,使用经验分析的方法对模拟系统的可用性和效率进行了评估。 / Li, Shun. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 105-116). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in also Chinese. / Abstract --- p.i / Acknowledgement --- p.vi / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Vascular Modeling --- p.14 / Chapter 2.1 --- Introduction and Related Work --- p.14 / Chapter 2.2 --- Vascular Skeleton Graph Construction --- p.15 / Chapter 2.2.1 --- Chamfer distance transform and Dijkstra's shortest-path algorithm --- p.17 / Chapter 2.2.2 --- End vertices retrieval --- p.19 / Chapter 2.2.3 --- The algorithm of vascular skeleton extraction --- p.21 / Chapter 2.3 --- Vascular Modeling --- p.21 / Chapter 2.3.1 --- Tubular Model --- p.21 / Chapter 2.3.2 --- Bifurcation Model --- p.23 / Chapter 3 --- Catheter Simulation --- p.28 / Chapter 3.1 --- Introduction and Related Works --- p.28 / Chapter 3.2 --- Catheter Simulation --- p.31 / Chapter 3.2.1 --- Kirchhoff Theory of Elastic Rod --- p.32 / Chapter 3.2.2 --- Problem Formulation --- p.34 / Chapter 3.2.3 --- The Multigrid Iterative Solver --- p.38 / Chapter 3.3 --- Collision detection --- p.45 / Chapter 3.4 --- Validation of the Catheter Simulation Method --- p.47 / Chapter 3.4.1 --- Stability --- p.49 / Chapter 3.4.2 --- Time Performance --- p.50 / Chapter 3.4.3 --- Preservation of Curved Tip --- p.51 / Chapter 3.4.4 --- The realism of catheter deformation --- p.53 / Chapter 4 --- Coil Embolization Simulation --- p.59 / Chapter 4.1 --- Introduction and Related Work --- p.59 / Chapter 4.2 --- Methodology --- p.61 / Chapter 4.2.1 --- Total potential energy of a coil --- p.61 / Chapter 4.2.2 --- The FEM-based numeric solver for interactive coil simulation --- p.61 / Chapter 5 --- Angiography Simulation --- p.70 / Chapter 5.1 --- Introduction and related works --- p.70 / Chapter 5.2 --- The Equations of Fluid --- p.72 / Chapter 5.3 --- Layered Cylindrical Gird Model --- p.73 / Chapter 5.4 --- Numerical Method --- p.76 / Chapter 5.4.1 --- Evaluation of the velocity field of blood flow --- p.76 / Chapter 5.4.2 --- Evaluation of the density field --- p.78 / Chapter 5.5 --- Results --- p.81 / Chapter 6 --- System Implementation and Evaluation --- p.84 / Chapter 6.1 --- Introduction and Related Work --- p.84 / Chapter 6.2 --- System Construction --- p.85 / Chapter 6.3 --- Empirical Study of the Training System --- p.89 / Chapter 7 --- Conclusion and Discussion --- p.98 / Chapter 7.1 --- Geometric Modeling of Vasculature --- p.99 / Chapter 7.2 --- Catheterization Simulation --- p.99 / Chapter 7.3 --- Embolization Simulation --- p.100 / Chapter 7.4 --- Angiography Simulation --- p.101 / Chapter 7.5 --- System and Evaluation --- p.102 / Publication List --- p.103 / Bibliography --- p.105
98

Histerectomia laparoscópica: estudo comparativo entre laparoscopia com múltiplas punções e punção única umbilical / Laparoscopic hysterectomy: Comparative study between multiport and single-port laparoscopy

Renata Assef Tormena 18 August 2016 (has links)
A histerectomia é um dos procedimentos cirúrgicos mais frequentes em Ginecologia. As técnicas minimamente invasivas trazem benefícios às pacientes e possibilitam o retorno precoce às atividades diárias. O presente estudo envolveu 42 pacientes do Setor de Laparoscopia da Divisão de Clínica Ginecológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo com indicação de histerectomia. As pacientes foram randomizadas em dois grupos: HLM (21 pacientes submetidas à histerectomia total laparoscópica com 3 punções) e HLU (21 pacientes submetidas à histerectomia total laparoscópica com punção única umbilical). Foram analisados tempo cirúrgico, sangramento operatório (variação de hemoglobina pré e pós-operatória, e volume de sangue aspirado durante a cirurgia), resposta inflamatória aguda (dosagens seriadas de Proteína C Reativa, de citocinas: interleucina-6, interleucina-10, fator de necrose tumoral alfa, fator de crescimento endotelial vascular e de leucócitos), complicações operatórias imediatas e tardias, dor pós-operatória (escala visual analógica de dor) e grau de satisfação das pacientes (questionário validado de qualidade de vida SF36). O tempo cirúrgico foi significativamente maior no grupo das histerectomias por punção única umbilical comparado ao grupo de múltiplas punções (p= 0,001). O sangramento operatório foi semelhante entre os dois grupos. Não ocorreram complicações imediatas maiores, porém, em um caso de HLU, houve necessidade de realização de duas punções auxiliares para lise de extensas aderências pélvicas. Em relação à resposta inflamatória, os grupos se comportaram de forma semelhante nas dosagens de IL-6 (p = 0,833), IL-10 (p = 0,420), TNF alfa (p = 0,098), VEGF (p =0,092) e leucograma (p = 0,712). Embora o comportamento da proteína C-reativa tenha sido diferente entre os dois grupos, seus valores médios não apresentaram diferença estatisticamente significativa em nenhum momento avaliado (p = 0,666). A análise subjetiva da dor foi semelhante nos dois grupos estudados. Um ano após a cirurgia, verificamos a presença de hérnia umbilical em três pacientes submetidas à histerectomia por punção única umbilical, sem diferença significativa em relação à cirurgia com múltiplas punções (p = 0,09). Além disso, houve melhora da qualidade de vida em ambos os grupos, segundo avaliação feita antes e um ano após a cirurgia. Conclusões: A HLU apresentou tempo cirúrgico maior do que HLM; entretanto, não observamos diferença entre os grupos em relação ao sangramento operatório, à resposta inflamatória, à dor pós-operatória, às complicações e à qualidade de vida. As duas técnicas propostas para realização de histerectomia laparoscópica foram viáveis e seguras. Há limitações da técnica com punção umbilical única para pacientes com úteros volumosos ou com múltiplas aderências pélvicas / Hysterectomy is one of the most common surgical procedures in gynecology. Minimally invasive techniques bring benefits to patients and including early return to normal activities. This study included 42 women candidates to hysterectomy at the Gynecological Clinic Division of Clinics Hospital of São Paulo University Medical School. The patients were randomized in two groups: HLM (21 patients underwent to total laparoscopic hysterectomy with three abdominal incisions) and HLU (21 patients underwent to total laparoscopic hysterectomy with single umbilical incision). The surgical time, blood loss (pre and postoperative hemoglobin variation and total blood volume aspirated during the surgery), complications rate, acute inflammatory response (C-reactive protein, interleukin-6, interleukin-10, tumor necrosis factor alpha, vascular endothelium growth factor and leucogram), postoperative pain (Visual Analogical Pain Score) and patient satisfaction (Short Form 36 Health Survey) were analyzed. The operative time was significantly larger in the umbilical single incision hysterectomy group compared to the multiple incisions group (p = 0,001). Blood loss was similar in both groups. There were no major immediate complications; however, one hysterectomy started with single incision needed two additional trocars to remove extensive pelvic adhesions. In terms of inflammatory response, both groups were similar in terms of IL-6 (p = 0,833), IL- 10 (p = 0,420), TNF alfa (p = 0,098), VEGF (p =0,092) and leucogram (p = 0,712) measures. Although the C-reactive protein behavior was different between the groups, their average values showed no statistically significant difference in any evaluated moment (p = 0,666). Pain evaluation was similar in both groups. Twelve months after surgery we observed the presence of umbilical hernia in three patients submitted to single-port hysterectomy, with no significant difference compared to multiport hysterectomy (p = 0,098). There was improvement in quality of life, according assessment before and after surgery in both groups. Conclusions: Singleport laparoscopic hysterectomy did have significantly larger operative time than multiport laparoscopic hysterectomy; however, no difference was observed between the groups in terms of operative bleeding, inflammatory response, postoperative pain and quality of life. Both techniques for laparoscopic hysterectomy were feasible and safe. Single-port hysterectomy presented technical limitations in patients with large uterus or extensive pelvic adhesions
99

Histerectomia laparoscópica: estudo comparativo entre laparoscopia com múltiplas punções e punção única umbilical / Laparoscopic hysterectomy: Comparative study between multiport and single-port laparoscopy

Tormena, Renata Assef 18 August 2016 (has links)
A histerectomia é um dos procedimentos cirúrgicos mais frequentes em Ginecologia. As técnicas minimamente invasivas trazem benefícios às pacientes e possibilitam o retorno precoce às atividades diárias. O presente estudo envolveu 42 pacientes do Setor de Laparoscopia da Divisão de Clínica Ginecológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo com indicação de histerectomia. As pacientes foram randomizadas em dois grupos: HLM (21 pacientes submetidas à histerectomia total laparoscópica com 3 punções) e HLU (21 pacientes submetidas à histerectomia total laparoscópica com punção única umbilical). Foram analisados tempo cirúrgico, sangramento operatório (variação de hemoglobina pré e pós-operatória, e volume de sangue aspirado durante a cirurgia), resposta inflamatória aguda (dosagens seriadas de Proteína C Reativa, de citocinas: interleucina-6, interleucina-10, fator de necrose tumoral alfa, fator de crescimento endotelial vascular e de leucócitos), complicações operatórias imediatas e tardias, dor pós-operatória (escala visual analógica de dor) e grau de satisfação das pacientes (questionário validado de qualidade de vida SF36). O tempo cirúrgico foi significativamente maior no grupo das histerectomias por punção única umbilical comparado ao grupo de múltiplas punções (p= 0,001). O sangramento operatório foi semelhante entre os dois grupos. Não ocorreram complicações imediatas maiores, porém, em um caso de HLU, houve necessidade de realização de duas punções auxiliares para lise de extensas aderências pélvicas. Em relação à resposta inflamatória, os grupos se comportaram de forma semelhante nas dosagens de IL-6 (p = 0,833), IL-10 (p = 0,420), TNF alfa (p = 0,098), VEGF (p =0,092) e leucograma (p = 0,712). Embora o comportamento da proteína C-reativa tenha sido diferente entre os dois grupos, seus valores médios não apresentaram diferença estatisticamente significativa em nenhum momento avaliado (p = 0,666). A análise subjetiva da dor foi semelhante nos dois grupos estudados. Um ano após a cirurgia, verificamos a presença de hérnia umbilical em três pacientes submetidas à histerectomia por punção única umbilical, sem diferença significativa em relação à cirurgia com múltiplas punções (p = 0,09). Além disso, houve melhora da qualidade de vida em ambos os grupos, segundo avaliação feita antes e um ano após a cirurgia. Conclusões: A HLU apresentou tempo cirúrgico maior do que HLM; entretanto, não observamos diferença entre os grupos em relação ao sangramento operatório, à resposta inflamatória, à dor pós-operatória, às complicações e à qualidade de vida. As duas técnicas propostas para realização de histerectomia laparoscópica foram viáveis e seguras. Há limitações da técnica com punção umbilical única para pacientes com úteros volumosos ou com múltiplas aderências pélvicas / Hysterectomy is one of the most common surgical procedures in gynecology. Minimally invasive techniques bring benefits to patients and including early return to normal activities. This study included 42 women candidates to hysterectomy at the Gynecological Clinic Division of Clinics Hospital of São Paulo University Medical School. The patients were randomized in two groups: HLM (21 patients underwent to total laparoscopic hysterectomy with three abdominal incisions) and HLU (21 patients underwent to total laparoscopic hysterectomy with single umbilical incision). The surgical time, blood loss (pre and postoperative hemoglobin variation and total blood volume aspirated during the surgery), complications rate, acute inflammatory response (C-reactive protein, interleukin-6, interleukin-10, tumor necrosis factor alpha, vascular endothelium growth factor and leucogram), postoperative pain (Visual Analogical Pain Score) and patient satisfaction (Short Form 36 Health Survey) were analyzed. The operative time was significantly larger in the umbilical single incision hysterectomy group compared to the multiple incisions group (p = 0,001). Blood loss was similar in both groups. There were no major immediate complications; however, one hysterectomy started with single incision needed two additional trocars to remove extensive pelvic adhesions. In terms of inflammatory response, both groups were similar in terms of IL-6 (p = 0,833), IL- 10 (p = 0,420), TNF alfa (p = 0,098), VEGF (p =0,092) and leucogram (p = 0,712) measures. Although the C-reactive protein behavior was different between the groups, their average values showed no statistically significant difference in any evaluated moment (p = 0,666). Pain evaluation was similar in both groups. Twelve months after surgery we observed the presence of umbilical hernia in three patients submitted to single-port hysterectomy, with no significant difference compared to multiport hysterectomy (p = 0,098). There was improvement in quality of life, according assessment before and after surgery in both groups. Conclusions: Singleport laparoscopic hysterectomy did have significantly larger operative time than multiport laparoscopic hysterectomy; however, no difference was observed between the groups in terms of operative bleeding, inflammatory response, postoperative pain and quality of life. Both techniques for laparoscopic hysterectomy were feasible and safe. Single-port hysterectomy presented technical limitations in patients with large uterus or extensive pelvic adhesions
100

Patients’ perspectives on recovery from day surgery

Berg, Katarina January 2012 (has links)
A large number of elective surgical patients in Sweden and elsewhere have their surgical procedure performed in a day surgery context. The surgical care event, with its postoperative surveillance, is brief at the surgery unit and patients are discharged home with the intention that they should manage postoperative recovery mainly themselves. However, several patients attest to being in an exposed situation when assuming responsibility for recovery at home. The overall aim of this thesis was to attain comprehensive knowledge of postoperative recovery following day surgery from a patient perspective. A questionnaire, the Post-discharge Surgical Recovery scale, was translated into Swedish and evaluated regarding its psychometric properties in a Swedish context. A sample of 607 day surgery patients who had undergone orthopaedic, general or gynaecological surgery self-rated their recovery at postoperative Days 1, 7 and 14 using the Post-discharge Surgical Recovery scale and the Quality of Recovery-23. Health-related quality of life was assessed before and 30 days after the surgical procedure, using the EQ-5D. In a second sample, 31 patients were interviewed in their homes regarding their recovery after day surgery. The interviews were conducted on postoperative Days 11-37, and focused on the meaning of recovery, self-care and perceptions of recovery. Data were explored by means of a phenomenographic analysis. The Post-discharge Surgical Recovery scale showed satisfactory psychometric properties when used among Swedish day surgery patients. Following discharge, recovery included both physical and emotional perspectives. Recovery varied, and influencing factors were found to be type of surgery, age, perceived health and emotional status on the first postoperative day. Orthopaedic patients had a more protracted recovery process compared to general surgery and gynaecological patients, along with more postoperative pain and lower health-related quality of life. Patients perceived that postoperative recovery comprised different internal and external factors and a large amount of responsibility regarding their recovery and surgical outcome. To be prepared for recovery at home, patients wanted knowledge and understanding about the normal range of recovery following their specific surgical procedure, and needed support from different sources in their surroundings. This thesis provides insight into day surgery patients’ postoperative situation. Based on the studies, individualized and well thought-out support appears favourable in order to have confident and well prepared patients at home. In contrast to smooth and easy patient care at the surgery unit, the postoperative phase seems to be a weak link in the day surgical continuity of patient care. Postoperative care needs to be further improved to increase quality and patients’ overall satisfaction with the day surgical experience. Attention should be paid to patients’ physical and emotional resources and needs.

Page generated in 0.5798 seconds