Publications by authors named "Kormos R"

This study empirically evaluates the quality of life (QOL) effects associated with hospital discharge among heart transplant candidates whose lives are maintained by left ventricular support systems (LVAS). Thirty-five LVAS inpatients (18 Novacor, 17 Thoratec) received structured QOL assessments approximately 1 month after device implant. Ten of the patients (8 Novacor, 2 Thoratec) were subsequently discharged to either home or a home-like outpatient facility where their QOL was reassessed.

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Chronic testing of the Nimbus/UOP Axial Flow Pump was performed on 22 calves for periods of implantation ranging from 27 to 226 days (average, 74 days). The following parameters were measured: plasma free hemoglobin, blood and plasma viscosity, erythrocyte deformability and mechanical fragility, oxygen delivery index (ODI), blood cell counts, hematocrit, hemoglobin, blood urea nitrogen, creatinine, bilirubin, total protein, fibrinogen, and plasma osmolality. Most of the above parameters were stable during the full course of support.

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Posttraumatic stress disorder associated with transplantation (PTSD-T) is a complication for some heart transplant recipients. By using a structured, standardized interview and DSM-III-R criteria, the authors examined whether recipients (n = 158) and their family caregivers (n = 142) showed similar PTSD-T rates and clinical characteristics during the first year posttransplant. Among the recipients, 10.

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The CardioWest total artificial heart (TAH) is a pneumatic device that is used as a bridge to heart transplantation and the only TAH available that totally replaces the failing ventricles. It has been utilized in selected centers in the U.S.

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Jointly developed by members of the American Society for Artificial Internal Organs and the Society of Thoracic Surgeons along with staff from the Food and Drug Administration, the National Heart, Lung and Blood Institute and other experts, this recommendation describes the reliability considerations and goals for Investigational Device Exemption and Premarket Approval submissions for long-term, mechanical circulatory support systems. The recommendation includes a definition of system failure, a discussion of an appropriate reliability model, a suggested in vitro reliability test plan, reliability considerations for animal implantation tests, in vitro and animal in vivo performance goals, the qualification of design changes during the Investigational Device Exemption clinical trial, the development of a Failure Modes Effects and Criticality Analysis, and the reliability information for surgeons and patient candidates. The document will be periodically reviewed to assess its timeliness and appropriateness within five years.

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Background: We performed a controlled study of a total artificial heart in bridge to transplantation. We hypothesized that the CardioWest total artificial heart used in a selected population of decompensating cardiac transplantation candidates would result in improved survival compared with matched controls.

Methods: The CardioWest trial started in 1993 in six United States institutions under an investigational device exemption from the Food and Drug Administration.

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The geometric configuration of the cannula connection to the left ventricular (LV) apex was studied with respect to several characteristics defining functionality and compatibility. The authors had previously determined, through in vivo studies in sheep, that the design of the cannula used with a dynamic blood pump for LV circulatory support can significantly affect the hemodynamics by improving both the bypass flow rate and the fluid dynamics within the ventricle. The tip of the cannula can aid in preventing wall to wall ventricular collapse, as well as septal shift, due to reduced LV pressure.

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Long-term survivors of cardiac transplantation are at risk for nephrotoxicity caused by many years of immunosuppressive therapy with cyclosporine or tacrolimus. We report on 12 patients who received heart transplants at the University of Pittsburgh, with subsequent development of end-stage renal disease (ESRD), who received renal replacement therapy at the university affiliated dialysis program. Patients were grouped by initial dialysis modality as intent to treat.

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Nimbus Inc. (Rancho Cordova, CA) and the University of Pittsburgh have completed the second year of development of a totally implanted axial flow blood pump under the National Institutes of Health Innovative Ventricular Assist System Program. The focus this year has been on completing pump hydraulic development and addressing the development of the other key system components.

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The CardioWest total artificial heart is a pneumatically driven device that totally replaces the failing ventricles. It is currently used as a bridge to heart transplantation in selected centers in the United States under a study by the Food and Drug Administration. Twenty-seven patients have undergone placement of the total artificial heart since 1993 with the intention to bridge to transplantation.

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Background: Traumatic aortic rupture is a relatively uncommon lesion that presents the cardiothoracic surgeon with unique challenges in diagnosis and management. To address controversial aspects of this disease, we reviewed our experience.

Methods: The study was performed by retrospective chart review.

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Background: The purpose of this study was to determine which patients on a cardiac transplantation list required a ventricular assist device.

Methods And Results: In a preliminary study, 26 patients with decompensated severe New York Heart Association class IV chronic heart failure were studied. Blood levels for sodium, hemoglobin, cytokines, neurohormones, and hemodynamics were obtained.

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The development of a percutaneous artificial internal organ system requires a reliable biocompatible connection between the external environment and the inside of the human body. Such is necessary for the success of a permanent left ventricular assist device. However, the search for a satisfactory interface at the epidermal level has proven to be difficult.

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A compact centrifugal blood pump has been developed as an implantable left ventricular assist system. The impeller diameter is 40 mm, and pump dimensions are 55 x 64 mm. This first prototype, fabricated from titanium alloy, resulted in a pump weight of 400 g including a brushless DC motor.

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We have been developing centrifugal pumps for an implantable left ventricular assist device. We manufactured 2 prototype centrifugal pumps (PI, PII). These two have similar designs except for the PII having a volute casing and a large output port.

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Background: Ongoing complement activation in patients with a ventricular assist device may contribute to observed hemostatic abnormalities and cellular aggregation by mediating leukocyte and platelet activation, formation of leukocyte-platelet conjugates, and the tissue factor pathway of coagulation.

Methods: Blood from 30 patients was collected before ventricular assist device implantation and during the implantation period. Plasma levels of thrombin-antithrombin III complexes, C3a, and SC5b-9 were measured by commercial enzyme-linked immunosorbent assay.

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Background: Partial left ventriculectomy (PLV) is a novel surgical treatment for severe heart failure consisting of resection of a large wedge of myocardium to reduce wall stress and restore the normal mass-volume ratio. Although ejection fraction (EF) has been shown to improve after PLV, few other physiological data describing its immediate effects on left ventricular (LV) performance are available.

Methods And Results: Eight patients, 58+/-5 years old, with severe clinical heart failure and EF of 12+/-3% were studied before and immediately after PLV.

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Background: Abciximab (ReoPro; Eli Lilly and Co, Indianapolis, IN) is a monoclonal antibody that binds to the platelet glycoprotein IIb/IIIa receptor and produces powerful inhibition of platelet function. Clinical trials of abciximab in patients undergoing coronary angioplasty have demonstrated a reduction in thrombotic complications and have encouraged the widespread use of this agent. We have observed a substantial incidence of excessive bleeding among patients who receive abciximab and subsequently require emergency cardiac operations.

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Jointly developed by members of the American Society for Artificial Internal Organs and the Society of Thoracic Surgeons along with staff from the Food and Drug Administration, the National Heart, Lung and Blood Institute and other experts, this recommendation describes the reliability considerations and goals for Investigational Device Exemption and Premarket Approval submissions for long-term, mechanical circulatory support systems. The recommendation includes a definition of system failure, a discussion of an appropriate reliability model, a suggested in vitro reliability test plan, reliability considerations for animal implantation tests, in vitro and animal in vivo performance goals, the qualification of design changes during the Investigational Device Exemption clinical trial, the development of a Failure Modes Effects and Criticality Analysis, and the reliability information for surgeons and patient candidates. The document will be periodically reviewed to assess its timeliness and appropriateness within five years.

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A 50-year-old man with a massive acquired sinus of Valsalva aneurysm presenting with coronary insufficiency is presented. Annuloaortic ectasia and severe aortic insufficiency mandated composite aortic valve and root replacement, with reimplantation of the coronary arteries. Clinical characteristics, treatment principles, and surgical outcomes are described.

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Background: The success of solid organ transplantation has resulted in an increasing pool of patients that subsequently require cardiac surgical procedures, yet the perioperative management of these patients is not well documented. We report a single institutional experience with the management techniques used and the outcomes of the cardiac surgical procedures performed in solid organ transplant recipients with functioning allografts.

Methods: Sixty-four patients underwent 66 cardiac procedures broken down as follows: coronary artery bypass grafting, 30; single or combined valve replacement-repair, 24; combined coronary artery bypass grafting and valve repair, 3; aortic repair, 4; pericardiectomy, 3; transmyocardial laser revascularization, 1; and native cardiectomy, 1.

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Background: Despite numerous reports published since the early 1970s, it is frequently asserted that quality of life (QOL) outcomes of transplantation have seldom been investigated and/or that little is known about QOL. This view may have persisted due to lack of adequate cumulation and synthesis of existing data. We performed an exhaustive, quantitative literature review to determine the nature and degree of any QOL benefits associated with transplantation in adults.

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Right ventricular assist devices (RVAD) are often needed on a short term basis in patients who develop RV failure after left ventricular assist device (LVAD) implantation. The purpose of this study was to use LVAD filling characteristics to help determine the timing for weaning a patient from RVAD support. Eleven patients (age 50 years +/- 15) supported with an LVAD (Novacor) and an RVAD (Biomedicus or ABIOMED) were studied.

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