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Bebek, Ozkan. "ROBOTIC-ASSISTED BEATING HEART SURGERY." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1201289393.
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Kesner, Samuel Benjamin. "Robotic Catheters for Beating Heart Surgery." Thesis, Harvard University, 2011. http://dissertations.umi.com/gsas.harvard:10016.
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Compliant and flexible cardiac catheters provide direct access to the inside of the heart via the vascular system without requiring clinicians to stop the heart or open the chest. However, the fast motion of the intracardiac structures makes it difficult to modify and repair the cardiac tissue in a controlled and safe manner. In addition, rigid robotic tools for beating heart surgery require the chest to be opened and the heart exposed, making the procedures highly invasive. The novel robotic catheter system presented here enables minimally invasive repair on the fast-moving structures inside the heart, like the mitral valve annulus, without the invasiveness or risks of stopped heart procedures. In this thesis, I investigate the development of 3D ultrasound-guided robotic catheters for beating heart surgery. First, the force and stiffness values of tissue structures in the left atrium are measured to develop design requirements for the system. This research shows that a catheter will experience contractile forces of 0.5 – 1.0 N and a mean tissue structure stiffness of approximately 0.1 N/mm while interacting with the mitral valve annulus. Next, this thesis presents the catheter system design, including force sensing, tissue resection, and ablation end effectors. In order to operate inside the beating heart, position and force control systems were developed to compensate for the catheter performance limitations of friction and deadzone backlash and evaluated with ex vivo and in vivo experiments. Through the addition of friction and deadzone compensation terms, the system is able to achieve position tracking with less than 1 mm RMS error and force tracking with 0.08 N RMS error under ultrasound image guidance. Finally, this thesis examines how the robotic catheter system enhances beating heart clinical procedures. Specifically, this system improves resection quality while reducing the forces experienced by the tissue by almost 80% and improves ablation performance by reducing contact resistance variations by 97% while applying a constant force on the moving tissue.Engineering and Applied Sciences
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Hellgren, Laila. "Heart Valve Surgery : Preoperative Assessment and Clinical Outcome." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5929.
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Lickteig, Crista. "Probiotics: Healthy Bacteria Used in Heart Surgery Patients." Thesis, The University of Arizona, 2011. http://hdl.handle.net/10150/144599.
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Post-operative infections are of high concern and are a great risk to patients who have just had an open-heart surgical procedure. Exposing the human body to elements it's clearly not used to, by opening the chest to perform heart surgery, greatly increases a patient's risk of infection. Surgery is usually the last line of defense used by physicians. This is not only because the invasiveness of the procedure, but because of the heightened risk of infection for the patient. In the treatment of surgical patients, the possibility of infection and protocol for treatment must be taken into account. Patients who undergo open-heart procedures, such as CABG's, Valve Repair/Replacement, Aneurysms, and Aortic Root Repair/Replacement, often have compromised immune systems. A compromised immune system, exposure of the chest cavity during surgery, and length of hospital stay are all contributing factors to hospital acquired infections (HAI). Infections vary depending on the nature of the surgery, the institution, surgical technique, and also varies by patient. Pneumonia, sepsis, bacterial endocarditis, and mediastinitis are all potential concerns in patients who have undergone recent open-heart surgery. The recent societal push for a more holistic approach to medicine and an effort for treatments with fewer side effects have lead to increased research in the realm of probiotics. Probiotics are "good bacteria" that are thought to aid in the intestinal microbial balance. They also have been shown to improve gastrointestinal problems. By integrating the use of probiotics into the treatment of post cardiac surgery patients, we expect to see a decrease in gastrointestinal problems and infections. We also believe that this will improve patients' overall health. This preventative treatment will save the hospital millions of dollars in revenue that is spent on treating infections and will also increase hospital bed turnover.
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Alshvang, Sofya. "Preoperative Nurses' Teaching for Open Heart Surgery Patients." ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/4587.
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Every year thousands of patients in the United States undergo cardiothoracic surgery. These patients have high levels of anxiety because they do not know what to expect. At the same time, many nurses on the cardiac telemetry/surgical floor are not aware that effective preoperative teaching can make a significant difference in patients' outcomes; thus, nurses had focused on postoperative teaching. The purpose of this project was to develop a preoperative teaching program through which nurses could help patients undergoing open heart surgery. The mentioned above practice initiative used Neuman's systems model as a framework. The project used a before-and-after design: Data were analyzed by comparing the results of preeducational and posteducational questionnaires. The goal of the program was to increase the level of knowledge of the nurses about preoperative education to a minimum of 90% correct answers. The findings showed that the knowledge of the nurses who attended the 1st educational intervention session increased from a baseline score of 87% to a posttest score of 95%, and the knowledge of the nurses who attended the 2nd session increased from a baseline score of 90% to a posttest score of 100%. The educational intervention also helped to improve communication between nurses and patients, and consequently, the quality of care. This project has implications for positive social change: The nurses' improved knowledge led to improved patient education, decreased patient anxiety and fear of the unknown, increased compliance with postoperative instructions, improved satisfaction with treatment, and positive postoperative outcomes.
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Limperopoulos, Catherine. "Neurodevelopmental sequelae in young children with congenital heart defects undergoing open heart surgery." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38223.
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Recent medical and surgical advances have greatly enhanced the survival of children with congenital heart defects that were once considered lethal or extremely debilitating. Consequently there now is a shift in concern from the integrity of the heart to that of the brain. Studies that describe the spectrum of developmental disabilities are lacking in these new survivors.The primary objective of this doctoral thesis was to characterize the extent and nature of neurodevelopmental impairments and disabilities in young infants with congenital heart defects, using a range of standardized developmental and functional measures, as well as electrophysiological techniques. A high prevalence of acute neurologic, motor, and global developmental impairments were present in our cohort at the time of surgery, and persisted well after surgical intervention. Moreover, functional difficulties and greater dependence in self-care and mobility were also common in this population. Somatosensory evoked potential abnormalities in newborns were found to be very predictive of developmental delays. Multiple markers (i.e. medical, surgical, developmental, and environmental) of brain injury were identified that appear to collectively mediate the outcome of this vulnerable group of children.
Clearly, this is a high-risk population that would benefit from routine developmental screening by rehabilitation specialists. This would facilitate early identification of those at risk and permit the institution of early intervention programs to maximize outcome and minimize burden of care.
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Sheppard, Stuart Vincent. "Leucocyte filtration and cardiac surgery." Thesis, University of Portsmouth, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310490.
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Collin, Sophie. "Preoperative planning and simulation for artificial heart implantation surgery." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S025/document.
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L'utilisation d'Assistance Circulatoire Mécanique (ACM) augmente dans le cas d'insuffisance cardiaque terminale ne répondant pas aux traitements médicaux. Dans ce contexte nous avons: 1) présenté une vue d'ensemble des problématiques cliniques, 2) élaboré une nouvelle approche de planification assistée par ordinateur pour l'implantation d'ACM, 3) implémenté un modèle CFD pour comprendre l'hémodynamique ventriculaire induite par la canule apicale. Afin de diminuer les complications, des critères quantitatifs optimisant la décharge ventriculaire pourraient être déterminés par CFD. La planification fournirait des informations permettant de choisir le dispositif et adapter la stratégie cliniqueMechanical Circulatory Support (MCS) therapy is increasingly considered for patients with advanced heart failure unresponsive to optimal medical treatments. In this context, we: 1) presented an overview of clinical issues raised by MCS implantation, 2) designed a novel computer-assisted approach for planning the implantation, 3) implemented a CFD model to understand the ventricle hemodynamics induced by the inflow cannula pose. With the aim of decreasing complications and morbidity, quantitative criteria for optimizing ventricle unloading could be determined through CFD, and the planning approach may provide valuable information for choosing the device and adapting the clinical strategy
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Wood, Nathan A. "Organ-Mounted Robots for Minimally Invasive Beating-Heart Surgery." Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/612.
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In the push to improve patient outcomes in cardiac interventions, minimally invasive beating-heart surgery is a major field of surgical research. However, interventions on a soft tissue organ under continuous motion through remote incisions pose a significant challenge. Endoscopic approaches eliminate the associated morbidity of median sternotomy, but they require either mechanical immobilization of the heart or robotic motion compensation of the tools, both of which have serious drawbacks. While mechanical immobilization may cause electrophysiological and hemodynamic changes in the performance of the heart, active compensation requires high-bandwidth manipulators to track the complex motion of the heart. In this thesis, we address the issue of physiological motion during minimally invasive beating-heart surgery through the use of organ-mounted robots. These devices eschew the high dexterity and actuation effort required of traditional surgical robots in favor of miniature robots that adhere directly to the operating site using vacuum pressure. Unlike mechanical stabilizers these devices are not fixed in the world frame and therefore do not immobilize the heart but instead move in unison with the heart providing a stable platform from which interventions may be administered. This thesis is built around two main contributions to the state of the art in robotic MIS. The first major contribution of this work is the development of spatiotemporal registration methods to improve positioning accuracy under virtual image guidance for organ-mounted robots. These efforts rely on frequencybased models, which capture the periodic motion of the heart, and anatomical models constructed from preoperative imaging. Using these models we estimate when in the physiological cycles the images were captured and the pose of the robot at that time to spatially align the models. Finally, we introduce a method for localizing these robots on the beating heart using function approximation that provides more accurate estimates over short time horizons. The second major contribution is the design and construction of new robots that provide a wider array of interventions using the organ-mounted paradigm. These efforts use emerging therapies as motivation for the design of an active cooling system for minimally invasive delivery of thermosensitive materials and a new parallel wire robot, known as Cerberus, for therapies that require coverage over large areas of the surface of the heart. Both of these new capabilities are demonstrated successfully in closed-chest beating-heart procedures. Overall, our contributions take a holistic approach to the advancement of the capabilities of organ-mounted robots. New form-factors provide specialized capabilities, while new approaches to registration improve our ability to accurately position these robots on the beating heart. Most importantly, everything presented in this thesis is demonstrated in closed-chest beating-heart procedures, or on data recorded in such a procedure.
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Masetti, Marco <1981>. "The medical management after surgery for advanced heart failure." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7101/1/masetti_marco_tesi.pdf.
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The aim of the Research of this Ph D Project is to improve the medical management after surgery for advanced heart failure, both after left ventricular assist devices (LVAD) implantation, and after heart transplantation in the long-term. Regarding heart transplantation (HTx), the Research Project is focused on diagnostics, classification, prevention and treatment of cardiac allograft vasculopathy (CAV), and on treatment of post-HTx cancers; the results are presented in the first part of this Thesis. In particular, the main aspect investigated are the prognostic role of information derived from coronary angiography, coronary tomography and intravascular ultrasound, and the different sensitivity of these techniques in predicting outcomes and in diagnosing CAV. Moreover, the role of mTOR inhibitors on CAV prevention or treatment is investigated, both alone and in combination with different anti-CMV prevention strategies, as well as the impact of mTOR inhibitors on clinical outcomes in the long term.
Regarding LVAD, the main focus is on the role of transthoracic echocardiography in the management of patients with a continuous-flow, centrifugal, intrapericardial pump (HVAD, Heartware); this section is reported in the second part of this Thesis. The main aspects investigated are the use of echocardiography in patients with HVAD device and its interaction with the information derived from pump curves' analysis in predicting aortic valve opening status, a surrogate of the condition of support provided by the LVAD.
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Masetti, Marco <1981>. "The medical management after surgery for advanced heart failure." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7101/.
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The aim of the Research of this Ph D Project is to improve the medical management after surgery for advanced heart failure, both after left ventricular assist devices (LVAD) implantation, and after heart transplantation in the long-term. Regarding heart transplantation (HTx), the Research Project is focused on diagnostics, classification, prevention and treatment of cardiac allograft vasculopathy (CAV), and on treatment of post-HTx cancers; the results are presented in the first part of this Thesis. In particular, the main aspect investigated are the prognostic role of information derived from coronary angiography, coronary tomography and intravascular ultrasound, and the different sensitivity of these techniques in predicting outcomes and in diagnosing CAV. Moreover, the role of mTOR inhibitors on CAV prevention or treatment is investigated, both alone and in combination with different anti-CMV prevention strategies, as well as the impact of mTOR inhibitors on clinical outcomes in the long term.
Regarding LVAD, the main focus is on the role of transthoracic echocardiography in the management of patients with a continuous-flow, centrifugal, intrapericardial pump (HVAD, Heartware); this section is reported in the second part of this Thesis. The main aspects investigated are the use of echocardiography in patients with HVAD device and its interaction with the information derived from pump curves' analysis in predicting aortic valve opening status, a surrogate of the condition of support provided by the LVAD.
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Padalino, Massimo. "Surgery for congenital heart disease in the adult age." Doctoral thesis, Università degli studi di Padova, 2008. http://hdl.handle.net/11577/3425554.
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Despite congenital heart malformations are currently treated in infancy and childhood, a great number of patients still need surgical treatment in adult age. For this reason, we have embarked on a multicentric study involving 7 major italian centers (Padova, Milano S.Donato, Milano Niguarda, Bergamo, Bologna, Massa, Napoli), so as to evaluate the impact of cardiac surgery in adults with congenital heart disease in our country and survival determinants. In addition, clinical late morbidity was analyzed in order to to evaluate correlated pre-operative and operative risk factors.
Methods
We collected data of 856 patients who underwent 1179 procedures from January,1st 2000 to December 31st 2004. Patients were divided into three groups: Group I- Palliation (3.1%): any operation performed to improve patientâ's clinical status without restoring normal anatomy or physiology. Bidirectional cavopulmonary anastomosis and pulmonary artery banding were the most frequent procedures.
Group II- Repair (69.7%): first operation performed in the patient, to achieve an anatomic or physiologic repair by separation of the pulmonary from systemic circulation (including also Fontan-types, and 1 and ’½ ventricle repairs). Most frequent procedures were: atrial septal defect closure (35.8%), partial anomalous pulmonary venous connection repair (7.2%), ventricular septal defect closure (5.3%).
Group III- Reoperation (27.4%): all procedures performed after repair either anatomic or physiologic. The most frequent procedures were conduit replacement (9.8%), aortic (8.6%) or pulmonary valve replacement (7.7%) .
Results
Preoperatively 34.6% of patients were in NYHA class I, 48.4% in class II, 14.2% in class III and 2.8% in class IV. Sinus rhythm was present in 83%.
There were 1179 procedure performed in 856 patients (1.37 procedure/patient), with a hospital mortality of 3.1%. Overall mean intensive care unit stay was 2.3 days (range:1-102 days). Major complications were reported in 247 pts (28.8%), with postoperative arrhythmias being the most frequent (26%).
At mean follow-up of 22 months (range 1 month- 5.5 years), 86% of data were available. Late death occurred in 5 patients (0.5%). Patients were in NYHA class I in 79.3 % , II in 17.6%, III in 2.9%, and only one patient in class IV (0.11%). Ability index was class I in 82%, class II in 13.7% and class III in 2.3%. Overall survival estimates is 82.6% , 99% and 91.8% at 5 years for groups I, II, III respectively. Freedom from adverse events at 5 years is 91% for acyanotic vs 63.9 % for preoperative cyanotic patients (p < 0.0001). Multivariate Cox analysis identifies among the most powerful incremental risk factors for survival preoperative NYHA class IV in cyanotic patients (Hazard Ratio-HR- 8.6, p value 0.001), preoperative NYHA class III (HR 2.7, p value 0.023), and reoperation (HR 2.3, p value 0.029). In addition, multivariate Cox analysis for postoperative morbidity expressed as NYHA class greater than 1, identifies among the most powerful incremental risk factors the length of ICU stay (HR 1.037, CI=1.002-1.072, p=0.036), number of operations (HR 1,445 CI=1,1213-1,721, p<0.001), cyanosis (HR 1,555, CI1,035-2,335, p=0,034), alteration of cardiac rhythm before surgery (HR 1,124, CI=1,040-1,215, p=0,03), pre-operative NYHA class>1 (Hazard Ratio 1,573, CI=0,954-2,593, p=0.076), age > 40y (HR 1,466, CI1,014-2,119, p=0.042).
Conclusions
Surgery for congenital heart disease in adult age is a safe and a low risk treatment. However patients with preoperative cyanosis show a higher incidence of late non-fatal complications. In addition, better preoperative clinical conditions are correlated with better late clinical outcomes, thus early repair (before cardiac and non cardiac organ deterioration occurs) is advocated.
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Dronavalli, Vamsidhar Bharadwaz. "Identification of heart donors using biochemical probes." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6096/.
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Heart transplantation provides a substantial survival benefit for selected patients with advanced heart failure, achieving a 1 year survival rate of ≥80%. Up to two thirds of hearts offered for transplantation are rejected before detailed organ inspection as being likely to fail if transplanted. The decision to discount these organs is based on clinical factors (e.g. blood pressure, electrocardiographic changes, prior cardiopulmonary resuscitation, drug history, history of hypertension and the need for inotropic support). However, none of these factors necessarily preclude successful transplantation. Thus, there is a pool of unused hearts, for which permission for heart donation has been granted, from which additional transplants could be generated if we could be more confident about their current and future function. My research prospectively validated a definition of primary allograft dysfunction following heart transplantation that is suitable for use in multicentre studies. I then investigated the role of biomarkers in the evaluation of potential cardiac donors with objective of increasing the number of donor hearts that will be assessed by direct inspection. This lead to the design of a scoring system to guide donor evaluation.
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Theobald, Karen. "Influences on Post-Discharge Recovery Following Coronary Artery Bypass Graft Surgery." Thesis, Griffith University, 2001. http://hdl.handle.net/10072/367398.
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Many things change following Coronary Artery Bypass Graft (CABG) surgery for both the patient and his/her carer. The major aim of this research was to provide an indepth examination of these changes to investigate influences on recovery. The study was devised on the premise that this information would provide a significant basis for hospital discharge planning.
A qualitative research approach, naturalistic inquiry, guided the study. Sixty people were interviewed, including thirty patients and their carers. Interviews were undertaken four to five weeks following discharge from hospital after CABG surgery. Subsequently, twelve months after the initial interview, patients and carers were again contacted to verify the findings generated from the first phase of the study, and to gain further data on his/her current health status.
Data analysis revealed a number of maj or themes and sub themes for patients and carers. Almost half the patients stated that heart surgery was a huge personal shock. Adjusting to life after surgery was difficult, and patients experienced some form of physical pain or change. An unexpected finding was the extent to which many of the patients were attuned to their post-operative physical adjustments. They spoke of mental and emotional changes as well as concerns over the financial burden of the surgery. Coming to terms with lifestyle adjustments and worrying about the future were other themes that emerged in patients’ accounts. They offered suggestions to improve support services, like establishing a twenty-four hour telephone chat line and forming community clubs to link up with other patients. In assisting to better prepare for discharge home, they suggested providing more information about what to expect during recovery, like the up and down days that they might experience.
Carers experienced a separate set of issues/needs and concerns as they came to terms with their loved one’s cardiac surgical recovery. The major findings for carers fell under four major themes, Events Surrounding Another’s Heart Surgery; Adjusting to the Surgery; Personal Changes Due to Surgery and Discovering Pathways to Recovery. Carers were shocked with the news that a family member required urgent cardiac surgery and theft reactions suggested a sequence of experiences that encountered in coming to terms with the event. Carers adjusted to the situation by taking on the role of watcher or minder and monitored the patient’s recovery. Some of the personal changes that carers dealt with, were changes in their activities and responsibilities; tiredness; experiencing a range of emotions and wonying about the unknown. Carers also offered suggestions for improved support services, like identifying a range of community services in close locality to his/her home. In better preparing for discharge home, some carers wanted more assistance and advice on how to be an effective carer.
This research study provides unique insights into the experiences of patients and carers after coronary bypass graft surgery in the first four to five weeks following discharge home from hospital. The study outlines the issues/concerns and needs of CABG patients and their carers after they leave hospital, highlighting those related to age, gender, and family support. For example, many patients commented that they were too young for this to occur. Gender differences included, that the majority of carers were females and male patients reported experiencing more pain following cardiac surgery. Family support was a critical factor in enhancing recovery. Study findings suggest the need for a re-examination of hospital discharge preparation and the further provision and monitoring of home support services.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Nursing
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Dunckley, Maria. "Barriers to recovery after coronary artery bypass grafting surgery." Thesis, Coventry University, 2007. http://curve.coventry.ac.uk/open/items/cb90ef80-269b-6eb1-2986-bb2c61227bb3/1.
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Introduction: Coronary artery bypass grafting surgery is an effective treatment for coronary heart disease for many patients; however, evidence suggests that there are some patients who do not report a good post-operative recovery. Although several studies have begun investigating possible reasons for these observations, little is known about the impact of CABG on quality of life and there still remains a lack of information that can help clinicians identify those people more likely to experience poorer recovery so that interventions can be targeted appropriately. Aims: The overall aim was to investigate barriers to and facilitators of recovery after CABG. Method: Phase 1 was a retrospective qualitative study involving semi-structured interviews with eleven patients who had undergone CABG and with ten health professionals experienced in caring for these patients. Data were analysed using thematic analysis. Phase 2 was a prospective study comprising two components, questionnaire and interview. The questionnaire included measures of quality of life, perceived recovery, demographic and psychosocial variables and was administered prior to surgery and at six and twelve months post-surgery. A sample of ten people who completed questionnaires were interviewed at the same time points and data analysed using framework analysis. Results: Interview data described the patient experience of undergoing CABG and identified components of a good recovery from the patient perspective. Patient and health professional participants identified numerous barriers and facilitators to recovery at three key time points - prior to surgery, during the hospital inpatient stay and post-CABG - and noted the complex inter-relationships between them, thus emphasising the need for a holistic approach to investigating recovery. Questionnaire data described the pattern of psychosocial functioning, quality of life and perceived recovery across the surgical pathway and identified depression and self-efficacy as the main predictors of post-CABG quality of life and perceived recovery. Using interview and questionnaire data a model of recovery is proposed. Conclusions: Findings from this research have identified a complex inter-related network of barriers and facilitators to recovery, suggested the possible mechanisms by which they impact on post-CABG outcome and identified recommendations for clinical practice.
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McWhorter, Linda G. "A Broken Heart| The Impact of Pediatric Open Heart Surgery on Parents' Wellbeing and Parenting." Thesis, The University of North Carolina at Charlotte, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10746597.
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According to the pediatric medical traumatic stress model, pediatric medical experiences can create posttraumatic stress symptoms (PTSS) in pediatric patients and in their parents and siblings. While the impact of traumatic medical experiences has been studied in parents of children with a variety of pediatric conditions, little is known about how the resulting PTSS may affect parenting. The relational PTSD model suggests that suboptimal parenting patterns can result from parental PTSS. One condition with high potential for traumatic medical events is critical congenital heart disease (CHD), which requires open heart surgery during infancy. This qualitative study examined the experience of parental PTSS and parenting in a sample of parents (N=12; 4 fathers, 8 mothers) of children with critical CHD. Using interpretive phenomenological analysis, focus group data were analyzed to determine 1) the ways in which CHD has affected parents’ lives; 2) the parents’ experience of PTSS related to CHD; 3) parenting patterns; and 4) the relationships between parental PTSS and parenting patterns. The following themes emerged: seeking/receiving social support, giving back, positive changes, overprotective and permissive parenting, and lasting effects of the traumatic medical experiences. Parents reported experiencing PTSS from all four PTSD symptom clusters. In addition, vicarious trauma and continuous traumatic stress were reported. Parents reported parenting patterns of overprotection and permissiveness; overprotection was suggested by the relational PTSD model. Finally, parenting a child with CHD was found to be a gendered experience, with fathers and mothers reporting different experiences on a variety of themes. Clinical considerations include the importance of parent to parent support, the different experiences of fathers and mothers, and the need to screen for PTSS among parents of children with CHD. Future research should consider quantitative studies with larger samples to assess the relationship between PTSD and parenting in this population.
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Brown, Katherine Louise. "The development and initial applications of a risk model to adjust for severity of case mix in paediatric cardiac surgery using the national audit database (UK Congenital Heart Audit)." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708446.
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Young-Raybold, Phillipa. "An investigation of neuropsychological outcome in paediatric heart surgery patients." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288404.
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Brinkman, Karen L. "Design of a microcomputer-based open heart surgery patient monitor." Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/76031.
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A patient monitor device for use during open heart surgery has been designed and constructed. The device uses a VIC 20 microcomputer along with some additional circuitry to monitor 3 separate functions. The first patient variable monitored is the blood flow rate through the extracorporeal blood circuit during surgery. The device also continuously monitors and displays 6 separate temperatures. Finally, 3 individual timers are monitored and displayed with the device. Both the hardware and the software used in the design are fully described.Master of Science
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Hall, Kevin. "Control of abnormal heart rhythms." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0026/NQ50181.pdf.
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Maynard, Charles. "Blacks in the coronary artery surgery study /." Thesis, Connect to this title online; UW restricted, 1986. http://hdl.handle.net/1773/8877.
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Waterhouse, Anna. "Bioengineering a coronary stent with covalently immobilised tropoelastin." Thesis, The University of Sydney, 2011. https://hdl.handle.net/2123/28916.
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This thesis describes the characterisation and development of covalently immobilised recombinant human tropoelastin (TE) on a plasma-activated coating (PAC) as a potential stent coating for the treatment of coronary artery disease. A biomimetic approach was used to create a biocompatible coating with an immobilised human protein to enhance biointegration of an implanted stent. A coating that enhanced endothelialisation while displaying low tbrombogenicity was developed and characterised in vitro and in vivo.
Covalent binding of TE to PAC was verified using ELISA and radiolabelled TE. Modulating the gas composition of the PAC, and therefore its mechanical and biological properties, resulted in varying amounts of covalently bound TE. The nitrogen containing PA Cs covalently bound up to 89± 1 % of physisorbed TE. The N2/Ar PAC covalently bound a monolayer of TE and was chosen for further characterisation. The covalent binding capacity of PAC extended for at least a year, retaining 65±1 % of its covalent TE binding capacity. Restoration of the full covalent binding capacity was achieved upon heat treatment of the PAC.
TE was shown to support the attachment and proliferation of endothelial cells (ECs) when physisorbed to tissue culture plastic (TCP). This was comparable to other adhesive extracellular matrix proteins, fibronectin and collagen. The morphology and distribution of ECs cultured on 316L SS, PAC and PAC+TE was investigated using reflective, fluorescence and scanning electron microscopy. PAC+TE supported increased endothelial attachment and proliferation compared to uncoated 3 l 6L SS and PAC. An EC phenotype was confirmed on 316L SS, PAC and PAC+TE by immunofluorescent labelling of endothelial cell specific markers, CD3 I and vWF.
As the thrombogenicity of blood contacting medical devices is crucial, methodology was developed to test the haemocompatibility of metallic surfaces in vitro. In static adhesion assays using whole heparinised blood, PAC was found to confer low thrombogenicity compared to 3 l 6L SS, and nitrogen again modulated this property. PAC and PAC+TE showed lower thrombogenicity than 316L SS after 60 min incubation. A modified Chandler loop was developed to test the tbrombogenicity of metallic surfaces in the presence of flowing blood. PAC and PAC+TE were again found to display low thrombogenicity, resulting in a 3-fold increase in the time to thrombus formation compared to 3 I 6L SS. This effect correlated with a 65±1 % increase in soluble P-selectin, a platelet activation marker on 3 l 6L SS. No significant platelet activation occurred on PAC or PAC+TE. The low thrombogenicity of PAC was retained for between 3 and 7 months. Furthermore, TE coated 3 I 6L SS displayed lower thrombogenicity than uncoated 316L SS, or fibronectin-or collagen-coated 316L SS.
The PAC was translated to a 316L SS laser cut stent for evaluation and in vivo testing. The PAC deposition was altered to coat all surfaces and resisted delamination. In vitro crimping and expansion of the PAC stent showed only the formation of nanocracks, compared to the large scale delamination observed on a commercially available Taxus Liberte stent. The covalent TE binding capacity and non-thrombogenicity of the PAC were maintained on the stent PAC.
The endothelialisation of PAC and PAC+TE stents was evaluated in vivo. This study marks the first comparator analysis of bare metal stents (BMS), PAC and PAC+ TE stents in a well-characterised model of rabbit bilateral iliac stenting. PAC and PAC+ TE stents were well tolerated and showed no gross inflammatory response. Cell coverage of stent struts occurred by 7 days post-implantation with endotheJialisation occurring both between the struts and over the struts in all samples. PAC and PAC+ TE showed no difference in the rate of endothelialisation compared to BMS, the standard corrunerciaJly available stents.
In further work, covalently immobilised TE was found to be susceptible to proteolytic cleavage by the common blood plasma proteases kallikrein and thrombin, which predominantly cleave TE at its arginine 515 residue. A mutant form of TE, R5 I 5A was shown to resist proteolytic cleavage at the 515 residue and thus retained the C-terminus of the protein which is required for cell attachment. This mutant form of TE retained the equivalent level of covalent binding to PAC and would therefore be a suitable candidate for application to a PAC stent for in vivo evaluation.
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De, Varennes Benoit. "Ex-vivo canine heart preservation : metabolic studies." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56680.
Full textAbstract:
The recently developed method of nuclear magnetic resonance spectroscopy allows for continuous monitoring of high energy phosphate compound (ATP and Phosphocreatine) and intracellular pH of tissues or whole organs. In other to better understand why ex-vivo hearts can be preserved for longer periods when perfused with oxygenated crystalloid solutions under hypothermic conditions, two groups of canine hearts were studied with nuclear magnetic resonance spectroscopy.Group 1 = Canine hearts preserved for 4 hours by immersion into a 4$ sp circ$C saline solution.
Group 2 = Canine hearts preserved for 24 hours by continuous coronary perfusion with a modified oxygenated Krebs solution at 4$ sp circ$C.
The longer preservation of ATP and phosphocreatine, as well as the slower decrease of intracellular pH in Group II hearts are hypothesized to be the reasons why perfused hearts can be preserved for longer periods of time.
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Verwey, Oriana. "The extent of discharge planning by nurses for patients who have undergone valvular surgery." Thesis, Nelson Mandela Metropolitan University, 2006. http://hdl.handle.net/10948/445.
Full textAbstract:
Valvular disorders can be corrected by means of surgery, after which very comprehensive discharge planning should be implemented to prevent the occurrence of post-operative complications. Advances in medical technology and intellect instigate earlier discharge for patients after they have undergone valvular surgery. The aim of this research study is to establish the extent of discharge planning by nurses for patients who have undergone valvular surgery, so that practice guidelines in the form of an in-service educational framework can be compiled for nurses in the management of these patients post-operatively. Patients, many of whom are from rural areas, are discharged without an adequate referral system. There are, currently, no set guidelines or referral persons to direct these patients during their rehabilitation period. Based on the researcher’s personal observations, it is evident that many patients suffer from bacterial endocarditis or clotted valves due to poor post-surgery management. However, both of these conditions could be avoided if proper health education was given to these patients. The study will take the form of a quantitative, exploratory, descriptive and contextual survey. Data will be collected by means of a structured questionnaire that will be completed by the nurses working in the cardiac general ward and the cardiac clinic. Findings of the research study will be used to assist the researcher in developing an in-service educational framework for staff that are both nursing and preparing post valvular surgery patients for discharge. The goal is to prevent complications such as clot formation and endocarditis and to enable patients to deal effectively with their rehabilitation period.
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Von, Oppell Ulrich O. "Myocardial protection during cardiac surgery." Thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/25887.
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Rosenthal, Eric. "Studies of the laser thermal probe in cardiovascular disease." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/25844.
Full textAbstract:
The initial use of optical fibres to transmit laser energy intravascularly was accompanied by a high rate of perforations and the production of inadequate vascular channels when used for recanalisation. The laser thermal probe - in which all laser energy is converted into heat by a metal cap at the tip of the fibre, prior to tissue application - was one of the earliest modifications designed to overcome these problems. The studies in this thesis were concerned with the application of the laser thermal probe to percutaneous peripheral and coronary artery angioplasty and His bundle ablation. In vitro studies were commenced in March 1987 when the first (argon) laser generator was installed in the cardiac catheterisation laboratory at Guy's Hospital and these were followed by clinical studies in three groups of patients: nine with peripheral artery occlusions, three with coronary artery stenoses and four with supraventricular arrhythmias using either argon or Nd-YAG energies. Suggestions that enhanced safety might be possible with on-line monitoring and/or control of the probe temperature were studied by recording the temperature responses in simulated circulations at flow rates observed clinically. The highly variable temperatures recorded in blood indicate that these measures are unlikely to contribute to improvements in either efficacy or clinical safety. An earlier report of successful peripheral artery recanalisation using the laser thermal probe was confirmed in the patients studied here, though a learning curve was evident. Coronary laser angioplasty had also been performed in a few patients with a similar device but without as much success. A more flexible "over the wire" laser probe was assessed here, first in cadaver coronary arteries and then in three patients undergoing coronary angioplasty. The lack of success seen with this laser thermal probe relates to the considerable differences found between peripheral and coronary arteries: percutaneous accessibility, vessel size and the susceptibility to thermal injury being the most important. These aspects and subsequent developments in coronary laser angioplasty are discussed further. The final chapter considers a hitherto new area for laser thermal probe application the interruption of arrhythmia circuits. Cadaver and electrophysiological studies indicated that ablation of the bundle of His might be possible with this device - without the need for a general anaesthetic. The course of the first patient ever to undergo this procedure is described, as well as the implications for percutaneous His bundle ablation using other energy sources.
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Mahjub, Hossein. "Logistic discrimination, screening and the simulation of a heart surgery department." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308030.
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Gold, Sasha Dione, and n/a. "Cognitive functioning of patients who develop delirium after cardiac surgery." University of Otago. Department of Psychology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070205.120554.
Full textAbstract:
In the present study the cognitive outcomes of cardiac surgery were examined in patients who did or did not develop delirium early post-operatively. The study expanded on previous research by investigating: (1) the relationship between delirium and functioning on specific cognitive domains; (2) the relationship between delirium and cognitive functioning after taking into account pre-existing cognitive impairment; and (3) the cognitive profile of delirium.
The study employed a non-equivalent pre-test post-test design. Participants were 80 candidates for coronary artery graft replacement and/or heart valve repair or replacement operations who were 60 years of age or over. Participants underwent a neuropsychological assessment pre-operatively, daily assessments between post-operative days 2-5 for identification of delirium, and a follow-up neuropsychological assessment 12 weeks post-operation.
Twenty-one participants met DSM-IV diagnostic criteria for delirium early post-operation. Participants who experienced delirium performed worse than participants who did not on one global cognitive measure and one specific cognitive domain at follow-up. However, this was likely due to the contribution of other factors such as age, years of schooling, pre-operative performance, and neurological events post-operation. There was no difference in the proportion of participants who did or did not develop delirium who met specified criteria for cognitive decline from pre-operation to follow-up.
Significantly more participants who developed delirium, relative to those who did not, met criteria for pre-existing cognitive impairment. After taking into account pre-existing impairment and other potentially contributing variables, delirium was a significant predictor of performance on an attentional task at follow-up.
There were no significant differences between the cognitive profiles of participants who did or did not develop delirium, at pre-operation or at follow-up. At both time points the profiles of these groups resembled the profile of a group of patients with vascular dementia.
In conclusion, although participants who experienced delirium performed worse on certain cognitive domains, this appeared to be due to factors other than delirium. However, after taking pre-existing cognitive impairment, and other relevant variables into account, delirium adversely affected attentional performance. Delirium was associated with a vascular dementia profile, but this profile was not specific to delirium.
Study findings have both theoretical and clinical implications. Consistent with the theoretical literature, the findings support impaired brain reserve as a risk factor for delirium, and the hypotheses that a combination of impaired brain reserve and events associated with delirium are responsible for subsequent cognitive performance. However, in the case of attention, events associated with delirium appear to be responsible for poorer performance, possibly due to the persistence of impaired attention, which is an essential feature of the delirium episode. A further theoretical implication is that individuals who experience delirium may be particularly vulnerable to developing vascular dementia, however, there needs to be further investigation of this risk in a non-cardiac surgery population. Clinically, study findings highlight the need to investigate possible cognitive impairment in individuals with cardiovascular disease, and in persons who experience delirium. When indicated, appropriate monitoring and/or treatment strategies should be employed to reduce the impact of cognitive deterioration.
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Vallely, Michael. "Inflammation, coagulation and off-pump cardiac surgery / by Michael Vallely." Thesis, The University of Sydney, 2005. https://hdl.handle.net/2123/27959.
Full textAbstract:
An estimated 800,000 patients per year worldwide undergo coronary artery bypass grafting (CABG), with significant survival and quality of life benefits. CABG may be performed with (on-pump) or without (off-pump) cardiopulmonary bypass (CPB).
30
Fisher, John. "Design development and evaluation of an improved pericardial bioprosthetic heart valve." Thesis, University of Glasgow, 1986. http://theses.gla.ac.uk/3994/.
Full textAbstract:
Pericardial bioprosthetic valves have shown good long-term clinical follow-up results over a period of 13 years with a low incidence of thrombo-embolism and calcification, and good haemodynamic function. However, doubts remain about the long-term durability of these valves and a significant incidence of primary tissue failure has been reported and this has been observed in our clinical series in Glasgow. I have identified tears in leaflets of explanted valves close to the edge of the cloth-covered stent which have caused prolapsed leaflets and large regurgitation. The performances of four pericardial valves, the Ionescu-Shiley Standard, Ionescu-Shiley Low Profile, Hancock and Mitral Medical pericardial valves have been evaluated in my test apparatus in an attempt to gain understanding of the mechanisms of these primary tissue failures. A hydrodynamic function test apparatus has been developed which allowed pressure difference, regurgitation and energy loss across the valve to be measured, and leaflet dynamics to be studied. Durability tests were carried out with Rowan Ash accelerated fatigue testers. The valve function and leaflet dynamics were dependent on the method of leaflet fixation, and the leaflet geometries and the coaption sutures used to close the leaflets together at the top of the posts. These could also affect the durability of the valves. However, accelerated fatigue test results showed premature failure for all four types of valves with tears in the leaflets caused by abrasion at the edge of the cloth-covered frames. In the Ionescu-Shiley Standard valve, tears were also seen at the commissure stitches. Although in these laboratory tests the mechanism of failure was abrasion and thinning of the leaflets as they were pulled over the edge of the cloth-covered frame, care has to be taken when extrapolating these results to clinical practice as biological effects, such as blood deposits on the cloth and tissue ingrowth, can reduce the abrasion to the leaflets at the edge of the frame. These processes are variable and leaflet abrasion on the cloth-covered frames remains the major cause of primary tissue failure in clinically explanted valves. The new three leaflet pericardial valve which I have developed has improved durability and comparable function in vitro to existing valves. The valve is based on a unique twin frame design. The inner support frame is covered with a single piece of bovine pericardium to reduce abrasion to the leaflets at the edge of the frame and has an array of radially-projecting pins and studs onto which the leaflets are mounted. The outer frame is covered with polyester cloth and this is located over the same radial pins to retain the leaflets in position. The assembled valve is secured with a fine locking ring in the base of the valve. The sewing ring is constructed from polyester cloth and can be positioned towards the inflow aspect of the valve in the aortic position to give a supra-annular configuration and away from the inflow aspect in the mitral position to reduce the length of post projecting into the ventricle. The posts on the outer frame are rounded to reduce the risk of damage of the ventricular wall, and a protective suture can be placed across the top of the posts to reduce the risk of suture-snaring during implantation in the mitral position. The mechanical properties of the pericardial tissue used for the leaflets have been investigated and fixation conditions analysed to produce uniform cross-linking throughout the tissue. Prototype valves have been tested with different leaflet geometries and differing methods of leaflet fixation, and an optimal leaflet geometry has been developed. The flexing position of the leaflet was moulded during fixation in a shape defined by two cylindrical surfaces which intersect in a spherical surface in the centre of the leaflet. This gave a stable closed position with deep coaption between the leaflets and synchronous movement of the leaflets to a uniform open position. Prototype valves have been manufactured in sizes 19 to 31 mm. Hydrodynamic tests on the prototype valves have shown comparable pressure difference, regurgitation and energy loss to other pericardial valves. Accelerated fatigue testers have shown greatly improved durability with eight out of nine valves cycled to over 400 million cycles, the equivalent of 10 years without failure. Implantation of size 25 mm valves in the mitral position in seven sheep for over three months has shown good short-term in vivo function. A randomised clinical trial is planned comparing a porcine valve with this improved pericardial valve.
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Leefe, Simon Edric. "Pulsatile flow testing and development of prosthetic heart valves in conduits." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335930.
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Mohammad, Sophia Nishat. "Effect of storage on tensile properties of natural heart valve tissue." Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/776190/.
Full textAbstract:
Aortic homograft valves are the preferred choice of replacement valve in aortic valve replacement procedures. The major drawback to their use is their availability. This project addressed two of the methods by which availability can be increased by assessing mechanical properties of the valves. Most pre-operative methods that assess homograft valve post-operative functional ability use biochemical or histological protocols. Rarely is their mechanical ability to sustain the pressure across them tested. Uniaxial tensile tests were performed on radial and circumferential leaflet sections from human and porcine aortic and pulmonary valves. The pulmonary valve has very similar anatomy to the aortic valve, although it is thinner and there is less pressure across it in vivo. When a patients own pulmonary valve is used to replace their aortic (their pulmonary valve is replaced with an aortic homograft), good post-operative results are achieved. The aim of this study was to see if pulmonary homografts would be able to sustain aortic pressures. It is concluded that pulmonary leaflet specimens have comparable mechanical characteristics to aortic and should therefore be suitable for aortic valve replacement. This would double the number of valves available for surgeons to use during valve replacements. Porcine aortic specimens were found to be stiffer and fail at higher stresses than the other valve types. The results from the porcine pulmonary specimen properties indicated that bioprosthetic valve manufacturers can consider their use in bioprosthetic valve manufacture as they are more than able to cope with human aortic valve pressures. Some storage methods have been assigned short duration or 'sell-by' dates, with no evidence that the mechanical integrity of the tissues has been significantly compromised. Currently retrospective studies are used to assess whether the treatments are detrimental to the tissues; the post-operative durability being taken as the indicator! If the storage times can be extended then the number of valves available to surgeons would increase. Four treatments of valves used for storage were tested over three months and their effect on leaflet specimen tensile properties determined. Glutaraldehyde had a significant effect on the tensile properties of the specimens and this suggests that alternative methods should be used to treat bioprosthetic valves, which are fixed in it. Treatment with antibiotics produced losses in stiffness of the tissues at three months, but these were within physiological limits. Therefore valves stored in this manner can be stored as long as three months at least with no effect on valve function in vivo. Cryopreservation with glycerol over three months produced less changes in specimen properties which again should not affect valve function in vivo. Cryopreservation with dimethyl sulphoxide (DMSO) caused the least difference in specimen properties compared to fresh tissues. It is therefore recommended as the first choice in valve treatments for storage. It is suggested that all new valve storage treatments be assessed for their mechanical effects on the tissues routinely. Preliminary work on a non-destructive intact valve test device using polarised light is introduced. This has potential for use in pre-operative assessment of valve mechanical integrity.
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Vosloo, S. M. "Closed mitral valvotomy in pregnancy." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/26260.
Full textAbstract:
Heart disease remains the most important non-obstetric cause of maternal mortality and morbidity during pregnancy, despite its low incidence of less than 1%. This is due to the decline in the number of deaths from haemorrhage, infection and toxemia. In addition, a striking change in the pattern of proportional distribution of organic heart disease in pregnant women is being noted, with a decrease in chronic rheumatic lesions and an increase in congenital cardiac disease. In the Third World rheumatic mitral valve disease remains a most important condition during pregnancy. It is currently rarely seen in Europe and the United States. Mitral stenosis is the most commonly encountered rheumatic heart lesion that complicates pregnancy. The normal circulatory changes during pregnancy aggravate this lesion as the reduced, fixed valve area obstructs blood flow from the left atrium to the left ventricle, causing pulmonary congestion and oedema. Careful and regular follow up of these patients is essential, and surgery is indicated if optimal medical management fails. Cardiac surgery duting pregnancy represents a risk to both the foetus and the mother. For most procedures extracorporeal circulation and heparinization are necessary and adds to the · adverse effects of the operation. Closed mitral valvotomy, however, is an excellent low risk operative procedure in patients with tight mitral stenosis without causing undue harm to the foetus. Cuttler described the first attempted surgery of the mitral valve in 1923 and since then the procedure has been improved to benefit many patients with tight mitral stenosis. The first reports of closed mitral valvotomy during pregnancy were in 1952. Al though a more precise valvotomy can be obtained with an open procedure, the closed operation avoids the risks of extracorporeal circulation, particularly detrimental to the foetus. This report is a review of the Groote Schuur Hospital experience of patients with mitral stenosis requiring closed mitral valvotomy during pregnancy since 1965. The aims of the study are to analyse the outcome of the pregnancy, the effects of valvotomy during pregnancy on both the mother and the foetus, and the outcome regarding restenosis of the mitral valve.
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Roche, Christopher David. "3D bioprinted heart patches for cardiac regeneration." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29577.
Full textAbstract:
BACKGROUND: epicardial patch transplantation is a promising approach to restore some of the cardiac
function lost after myocardial infarction (MI). Advances in 3D bioprinting, 3D cell culture and transplantation
methods at surgery have provided hope that this approach could soon benefit heart failure patients. The
optimal content of 3D bioprinted patches (the “bioink” extruded by a 3D bioprinter) is not known. Patches
containing a suspension of 3D vascularised cardiac spheroids (VCS; 3D aggregates of cells / microtissues) in
hydrogel may confer an advantage compared to freely suspended cells or hydrogel without cells. The
mechanisms underlying the benefit of epicardial patch transplantation approaches have not been fully
elucidated and this is needed for widespread clinical translation. To be fully compatible with cardiothoracic
surgical approaches in future, patches should be transplantable by minimally invasive robotic approaches.
METHOD: Alginate-gelatin (AlgGel) patches were optimised ex vivo for cardiac applications, followed by in
vivo transplantation of patches in mice modelling MI. For the ex vivo optimisation phase, three different
bioprinters were used to bioprint patches with different bioink contents which were incubated up to 28 days
and analysed. For the in vivo phase, new patches were 3D bioprinted using the optimal methods determined
in the previous (ex vivo) experiments and surgically transplanted to the epicardium in infarcted mice. For
these in vivo experiments, we cultured mixed cardiac cells: induced pluripotent stem cell derived
cardiomyocytes (iCMs), human coronary artery endothelial cells (HCAECs) and cardiac fibroblasts (CFs). Cells
were cultured using hanging drops to generate VCS which were suspended in AlgGel to create bioink for 3D
bioprinting of patches. Study control groups (in vivo) were: the same cells freely suspended in AlgGel, AlgGel
without cells, MI without treatment and sham surgery (no MI and no treatment). The primary outcome was
cardiac function (left ventricular ejection fraction, LVEF%) measured up to day 28 post surgery. Additional
analyses included: electrical mapping, histology, cell quantification by flow cytometry and mRNA (gene
expression) profiling. Alongside these experiments, we developed novel surgical robotic minimally invasive
instruments designed to transplant similar patches at human scale. We prototyped a heart patch transplanter
device and demonstrated its potential utility in a world-first operation on a pig cadaver. RESULTS: Ex vivo
patches incubated for 28 days allowed for self-organisation of endothelial cells into networks and contractile
activity within patches. In vivo transplantation of patches in mice modelling MI resulted in a “return to
baseline” improvement in median LVEF%. Our results measured median baseline (pre-surgery) LVEF% for all
mice at 66%. Post-surgery, LVEF% was 58% for Sham (non-infarcted) and 41% for MI (no treatment) mice.
Patch transplantation increased LVEF%: 55% (acellular; p=0.012), 59% (cells; p=0.106), 64% (spheroids;
p=0.010). The VCS group was associated with improved electrical mapping profiles, lower infarct sizes,
changes in host immune cell numbers and a gene expression (mRNA) profile which was closest to sham mice
(with no MI). As proof-of-concept, similar scaled-up AlgGel patches were successfully transplanted in a
porcine cadaver using a prototyped robotic minimally invasive surgical instrument. CONCLUSION: Epicardial
transplantation of patches improves cardiac function in mice modelling MI. The use of VCS in alginate-gelatin
bioink seems to offer advantages compared to freely suspended cells or hydrogel alone. The fact that
hydrogel alone without cells confers some restoration of myocardial function suggests that the mechanism
is not fully accounted for by the cellular portion of the bioink. Further studies are needed with a focus on
whether host immune cell modulation is a key mechanism underlying the benefit of this approach. Since our
most successful treatment group (VCS) had a similar transcriptome compared to non-infarcted (sham) mice,
further studies should also include transcriptomic analyses to confirm reproducibility of this finding. If it is
confirmed that immuno-genetic mechanisms underly patch-based approaches to myocardial protection after
MI, this may change the focus of treatment strategies and avoid wasted resources and potentially patient
harm (from treatments which are not aligned with the underlying mechanism). Our robotic minimally
invasive patch transplantation operation represents a first step on a potential pathway towards
transplantation at human surgery (without the need for traditional open surgery). For translatability, patch
development should work towards being compatible with robotic and/or minimally invasive transplantation.
35
Tseng, Stephanie Y. "Altered Erythropoiesis in Newborns with Congenital Heart Disease." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592170832331138.
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Hanke, Samuel P. M. D. "Readmission within 30 Days of Pediatric Cardiac Surgery: Incidence, Risk Factors and Resource Utilization." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384869980.
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Owen, Mallory. "Relationship between brain structure and function prior to open heart surgery in newborns with complex congenital heart defects." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116929.
Full textAbstract:
Infants with complex congenital heart defects (CHD) show evidence of impaired brain growth as well as neurobehavioural abnormalities prior to undergoing open heart surgery. The aim of this study was to evaluate the relationship between neurobehavioural performance and brain volume as well as white matter microstructure in full-term newborns with complex CHD before cardiac surgery using a standardized neurobehavioural assessment and quantitative magnetic resonance imaging (MRI) measures. Thirty-five newborns (>36 weeks gestational age) were evaluated. Advanced three-dimensional, volumetric MRI was used to measure global and tissue-specific brain volumes. In addition, the integrity of the corpus callosum, corticospinal tracts, and optic radiations was quantified using diffusion tensor imaging and post-acquisition fibre-tracking techniques to measure fractional anisotropy (FA) and mean diffusivity (Dav). Neurobehavioural status was evaluated with the Einstein Neonatal Neurobehavioural Assessment Scale (ENNAS). Reduced subcortical gray matter volume (SCGM) and increased cerebrospinal fluid volume (CSF) were associated with abnormal behavioural state (SCGM, p=0.04; CSF, p=0.007) and visual orienting (CSF, p=0.003) on the ENNAS. Lower Dav in the optic radiations was associated with overall ENNAS score (p=0.02) and active motility (p=0.006). Stratification for cardiac physiology revealed further associations between neurobehavioural performance and brain volumes as well as microstructure. This study demonstrates associations between impaired brain development and neurobehavioural abnormalities in newborns with complex CHD, extending our understanding of early brain structure and function in this population, and emphasizing the importance of early screening and intervention in order to improve developmental outcomes and quality of life.Les enfants ayant une malformation cardiaque congénitale (MCC) sont à risque de présenter un trouble de la croissance cérébrale ainsi que des problèms neurocomporatementaux avant même d'avoir subi une chirurgie cardiaque. L'objectif de cette étude était d'évaluer, dans le contexte préopératoire, les relations existant entre le comportement, le volume cérébral et la microarchitecture de la substance blanche chez les nouveau-nés présentant une MCC complexe en utilisant une évaluation neurocomportementale standardisée et des mesures quantitatives d'imagerie par résonnance magnétique (IRM). Trente-cinq nouveau-nés d'âge gestationnel supérieur à 36 semaines ont été évalués. Une technique de volumétrie cérébrale tridimensionnelle par IRM a été utilisée pour mesurer le volume cérébral régional et total. De plus, l'intégrité du corps calleux, du faisceau corticospinal et de la radiation optique a été quantifiée au moyen de la technique de tractographie par IRM en tenseur de diffusion qui permet de mesurer la fraction d'anisotropie (FA) et la diffusivité moyenne (Dmoy). Le statut neurocomportemental a été évalué à l'aide du Einstein Neonatal Neurobehavioural Assessment Scales (ENNAS). Une diminution de volume de la substance grise sous-corticale (SGSC) et une augmentation du liquide céphalorachidien (LCR) étaient associées avec des anomalies neurocomportementales hors norme (SGSC, p=0.04; LCR, p=0.007) de même qu'une orientation visuelle déficitaire (LCR, 0=0.003) tels que évalués par le ENNAS. Une faible Dmoy de la radiation optique était corrélée avec le score global du ENNAS (p=0.02) et avec une plus grande activité motrice (p=0.006). Des analyses de stratification selon le type d'anomalie morphologique cardiaque ont révélé d'autres associations entre la performance neurocomportementale et le volume et la microarchitecture cérébrale. Cette étude confirme de l'existence d'associations significatives entre l'altération du développement du cerveau et la présence d'anomalies neurocomportementales chez les nouveau-nés avec une MCC complexe. Ces résultats apportent une meilleure compréhension du développement des structures cérébrales et de leurs fonctions chez cette population tout en mettant l'emphase sur l'importance du dépistage et de l'intervention précoce afin de permettre un développement harmonieux et d'améliorer la qualité de vie.
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Sanborn, Kathryn L. "The lived experience of ruptured aortic aneurysm in adults." Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1036187.
Full textAbstract:
The experience of living through an unexpected, life-threatening cardiovascular surgery can be a profound. This study examined the experience of 4 men who had survived ruptured aortic aneurysm using a phenomenological research design.Audio-taped interviews were analyzed for common themes and patterns. Two strong, opposing constitutive patterns were found. The patterns the data conveyed were: 1) fear as a response to overwhelming pain and clouded perceptions, and 2) gratitude for recovery in an atmosphere of caring support.This study was significant in beginning to bring to understanding the phenomenon of surviving major, unexpected cardiovascular surgical trauma. It is recommended that health care providers be more attentive to similar patients' experiences and listen to how their lives have changed as a result of their experiences.School of Nursing
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Speiser, Bernadette Susan. "The relationship of threat appraisal and coping patterns in coronary artery bypass patients." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/845964.
Full textAbstract:
Coronary bypass surgery is an increasingly common occurrence. Current literature does not validate the coping mechanisms involved for patients facing this life-threatening event. Lazarus’ theory of stress and coping was utilized as the framework for the study. The purpose of the study was to identify the degree of threat coronary bypass surgery presents and coping mechanisms utilized with this specific insult. The significance of the study was to assist nurses in identification of perceived risks/benefits of having open heart surgery from the patient’s perspective. The population included patients from a private cardiovascular practice in Indianapolis, Indiana. The convenience sample included 38 subjects recovering from coronary bypass graft surgery. Subjects were identified as uncomplicated post-operative surgical patients and were mailed questionnaires one month after discharge from the hospital. The Jalowiec Coping Scale and a questionnaire for demographic data were utilized to collect data. Procedures for protection of human subjects were followed. The research design was non-experimental and descriptive, correlational procedures were utilized to analyze data.The data supported the notions that clients utilized both problem-focused coping and emotion-focused coping, and emotion-focused coping strategies were more effective in reducing the threat. Education was significantly related to emotive coping styles and clients that perceived a higher threat intensity utilized more emotion-focused coping strategies. Recognition of the need to minimize stressors can be an important role the nurse facilitates. Through participatory care, the nurse may assist in finding the meaning for the stressor and encourage open communication patterns and emotional responses. Allowing for reduction of threat perception and intensity may enhance the outcome of the experience.School of Nursing
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O'Regan, David John. "Activated protein C is a logical adjunct to heparin during cardiovascular intervention." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343805.
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Valdes-Perezgasga, Francisco. "Intramyocardial pH measurements using ion-sensitive field effect transistors." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254191.
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Swim, Megan Marie. "Stem cell tissue engineering and potential application in corrective congenital heart surgery." Thesis, University of Bristol, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.723504.
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Kurz, Gerhard [Verfasser], and U. [Akademischer Betreuer] Hanebeck. "Directional Estimation for Robotic Beating Heart Surgery / Gerhard Kurz ; Betreuer: U. Hanebeck." Karlsruhe : KIT Scientific Publishing, 2015. http://d-nb.info/1185761055/34.
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Weinberg, Eli 1979. "Multiscale simulations of the aortic heart valve : applications in disease and surgery." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44797.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 136-148).
This thesis presents mathematical models describing the mechanical behavior of the human aortic heart valve over a range of length and time scales. In the human heart, the valves perform the vital function of controlling the direction of blood flow. Each valve is an intricate mechanical structure, with distinct features and functions at multiple scales. This effort first develops a framework of reference configurations that enables communication between simulations of the different length scales. Three simulations are created within that framework. At the cell scale, the interaction between a single valvular interstitial cell and its surrounding matrix is described. At the tissue scale, a model is created for the valve cusp tissue mechanical behavior, including the multilayered, nonuniform geometry and nonlinear, anisotropic material properties. At the organ scale, a dynamic, three-dimensional model with fluid-structure interaction predicts the motion of the valve, blood, and surrounding tissue. Each simulation is verified against a number of experimental measures. These three simulations together constitute a model for the dynamic, three-dimensional, multiscale mechanical behavior of the healthy human aortic heart valve throughout the cardiac cycle. The model is employed to perform multiscale investigation into the mechanisms of the disease calcific aortic stenosis in three ways. First, the model of the healthy valve is extended to describe disease progression on the decade time scale. Calcification is introduced at the tissue level and the effects on valve function are monitored at the organ level. Second, the role of mechanical deformations in the disease process is examined by comparing multiscale deformations between the normal valve case and a known disease-prone case.
(cont.) Finally, a combined computational and experimental study investigates the role of fluid shear in calcific disease. Shears computed in the organ-scale simulation are applied to endothelial cells in vitro. The cells express disease-related genes in a manner consistent with the region-specific nature of calcific disease, providing evidence for a role of shear in the disease process. The multiscale model presented in this thesis has further utility in investigating function, disease, and therapy of the human aortic valve.
by Eli J. Weinberg.
Ph.D.
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Qarizadah, Muhammad Musa. "Impacts of Observing Live Open Heart Surgery on Young Adults' Health Behaviors." ScholarWorks, 2017. https://scholarworks.waldenu.edu/dissertations/3364.
Full textAbstract:
Having a heart healthy lifestyle at a younger age is beneficial in reducing the risk of coronary heart disease (CHD) in adulthood and various health education programs for CHD prevention exist to persuade young adults to adopt a heart healthy lifestyle. Little is known, however, about the influence of watching live open heart surgery on young adults' adoption of a heart healthy lifestyle. To address that gap in knowledge, this study was conducted at a health facility in Virginia where students came to observe live open heart surgery. The purpose of the study was to understand whether watching live open heart surgery can influence young adults' attitudes and behaviors towards adopting a heart healthy lifestyle. The theory of health belief model and the theory of reasoned action were used in guiding this research. A quantitative design involving observation and administration of surveys was used. A survey with questions about participants' lifestyle practices was administered prior to observation of open heart surgery and 3 or more months afterwards. A total number of 179 young adults at baseline were considered eligible for the study. Ages of the research participants were between 18 and 35 years old. The t test and ANOVA results showed no significant differences between baseline and follow up data with regards to changes in behaviors of young adult students towards adopting a heart healthy lifestyle. The study concluded that observing live heart surgery did not significantly change behaviors of the students in adopting a heart healthy lifestyle. In order to achieve the desired changes in attitudes and behavior of students, looking into other evidence based options and pursuing those that can influence and motivate young adult students to adopt a heart healthy lifestyle can be a positive social change.
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Painter, Mark Llewellyn. "Outcome after palliative cardiac surgery in a developing country." Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/25963.
Full textAbstract:
The outcome of 121 children who underwent palliative cardiac surgery at the Red Cross War Memorial Children's Hospital over a 5 year period, 1980 1984, was retrospectively examined. 79 children had systemic artery to pulmonary artery shunt operations (SPS), 40 had pulmonary artery bands (PAB) and 2 had surgical septectomies. SPS was most often done for children with Tetralogy of Fallot (TOF, 26 cases) or complex univentricular hearts with right ventricular outflow tract obstruction (27 cases). PAB was done chiefly for ventricular septa! defects, alone (VSD, 8 cases) or with coarctation of the aorta (9 cases). Children were referred from a wide area with 63 cases being referred from other major centres and foreign countries. Overall, 36 children died (30 % mortality): 5 died at surgery, 6 within 48 hours of surgery, a further 5 within 31 days; and 20 died after 31 days. SPS and PAB had the same early mortality rates ( 13 % ) • SPS had higher late and overall mortality rates (20 and 33 %) than PAB (10 and 23 %). Age at operation was found to be the most significant determinant of the overall mortality rate: children less than six months had a mortality of 42 % and those over 6 months, 13 % • The children were grouped into those with lesions which were probably correctable and those that were unlikely to be so, based on diagnosis and age at surgery: those with correctable lesions had a lower overall mortality (22 %) than those with uncorrectable lesions (43 %). Where the surgery was performed as an emergency, there was a higher overall and early mortality (55 and 35 respectively), compared to those operations which were performed electively ( 25 and 9 % ) • The presence of other medical conditions, for example congenital abnormalities and infections, was also a determinant of death (44 % mortality if other medical condition present, 26 % if absent). sex, population group, home address and type of surgery performed did not significantly affect mortality when examined by multivariate analysis. Using routine methods of follow up, it was initially thought that 17 % of all patients (22 % of survivors) were lost to follow up. An important determinant of this was the referral centre. 31 % of cases from other major centres and 20 % of foreign cases were lost, as compared to 8 % of cases from smaller towns near Cape Town and 2 % of children from Cape Town. Population group (35 % Blacks, 14 % Coloureds and 7 % Whites were lost), and palliative operation (23 % SPS, and 5 % PAB lost) were also significant determinants. It was possible to trace 12 of the 20 children who were thought to be lost to follow. 8 had died, 3 were still awaiting correction and 1 was traced and received corrective surgery. The records of the children who underwent cardiac surgery in 1987 were also analysed. There was no difference in the demographic characteristics of either group, and the early mortality was the same. This study shows that the outcome after palliative cardiac surgery is poor, with a high mortality rate and children often being lost to follow up. The decision to palliate rather than to correct a congenital heart defect must be made after balancing these risks with those of early correction for the particular surgical team. Should palliative surgery be undertaken, careful follow up is essential to ensure that complications of palliation do not set in and that corrective surgery is done at the optimal time.
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Trippenbach, Teresa Aniela. "Small hearts - grand matters. The ethics of neonatal treatment with unknown long-term outcome : the case of hypoplastic left heart syndrone." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29405.
Full textAbstract:
Ethical decisions about medical care of infants is based on the by proxy evaluation of the infants' best interests. Since parents and physicians may have different points of reference, conflicts may arise during the decision-making process. The decision about the infant's well being becomes even more complex when high risk treatment with an uncertain long-term outcome is considered. Surgical palliation of hypoplastic left heart syndrome (HLHS) is an example of such a treatment. I use this example in my discussion on the relevant ethical issues and possible roots of conflicts between the decision-makers.I argue that as long as long-term survival rates are variable, and the survivors' quality of life remains uncertain, palliative surgery for HLHS should not be obligatory. Rather, the parents should be informed not only about the existing treatments but also about the non-treatment option, and what each option may imply for the infant, parents and the family.
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LeRoy, James Allan 1955. "THE INCIDENCE AND PREDICTORS OF POST-SURGICAL CONFUSION IN CARDIAC TRANSPLANT RECIPIENTS (POST-CARDIOTOMY DELERIUM, HEART TRANSPLANTATION, OPEN-HEART SURGERY)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/275554.
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Thomson, Patricia. "Complex factors that influence patient and partner and dyad outcome 4 months after coronary artery bypass surgery." Thesis, University of Stirling, 2008. http://hdl.handle.net/1893/21183.
Full textAbstract:
Background: Coronary heart disease (CHD) remains a major cause of death and ill- health in Scotland. Coronary artery bypass grafting (CABG) aims to relieve CHD symptoms, improve quality of life and increase life expectancy in high-risk groups. Partners may positively or negatively influence patient outcome, and they too may be adversely affected by the experience of CABG. Health care is currently organised around the patient. The partner's is seen as merely assisting patient recovery. Their health and well-being is neglected despite them being at an increased risk of CHD. Research has been limited in the partner variables that have been examined. Their health needs and concerns and the influence of the patient on partner outcome have seldom been examined and the effects of CABG on the dyad. The dyad has not previously been examined as an outcome variable of interest.
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Cozac, JoAnn Lee. "Spouses’ experiences of having a mate in the Intensive Care Unit following coronary artery bypass graft surgery." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24413.
Full textAbstract:
It is generally recognized that a serious illness with concurrent hospitalization in an ICU will have an impact on family members. Few researchers, however, have described the ways in which spouses are affected when their mates are hospitalized in an ICU. Therefore, this study aimed to describe and explain the spouses' experiences of having a mate in an ICU following coronary artery bypass graft surgery.
Kleinman's conceptual framework guided the development of the research question and provided the focus for data collection and analysis. Kleinman proposes that an understanding of the client's perspective is necessary for the provision of effective health care.
A qualitative research method based on the theoretical perspective of phenomenology was used to answer the research question. The spouses' viewpoints were elicited through unstructured interviews. The sample consisted of seven spouses, four women and three men. The spouses were interviewed on two occasions, once while their mate was still in the ICU and once shortly following their mate's discharge from the ICU. A total of 13 in-depth interviews were conducted over a 3 month period.
Data were analyzed simultaneously with and following data collection. Responses that were similar were grouped together into categories. After the data were examined and sorted into categories, the researcher defined the theme that dominated each category. The themes that emerged from the data were clarified, validated, and/or rejected by the participants during subsequent interviews. As relationships between the categories were identified, the important aspects of the spouses' experiences became apparent.
The findings revealed that the spouses located the ICU experience within the context of their experience with their mate's coronary artery bypass graft surgery. The spouses understood and made sense of the ICU experience by attaching meaning to specific events that related to the entire surgical experience. They perceived the surgical experience as consisting of three distinct but interrelated phases: pre-surgery; waiting during surgery; and post-surgery. During each phase, the spouses described and explained how they reacted to and coped with each new situation. These two themes, "reaction to the situation" and "coping with the situation," appeared as threads throughout the entire surgical experience. By organizing the data in relation to phases and themes, the researcher was able to meaningfully understand and communicate the spouses' entire surgical experience.
In view of the study findings, implications for nursing practice, education and research are delineated.Applied Science, Faculty of
Nursing, School of
Graduate