Artificial organs
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Comparative Study
Comparison of a new heparin-coated dense membrane lung with nonheparin-coated dense membrane lung for prolonged extracorporeal lung assist in goats.
Thrombosis and bleeding are major complications in cases of prolonged extracorporeal lung assist (ECLA) with an artificial-membrane lung. Antithrombogenic treatment of the artificial-membrane oxygenator and circuits is indispensable for safe ECLA. The efficacy of a new heparin-coated membrane lung with minimal systemic heparinization was evaluated for 7 days and compared with a nonheparin-coated membrane lung in goats. ⋯ There was no plasma leakage from the artificial lung. Although several clots were observed in the stagnant areas of the artificial lung, they did not lead to deterioration of the function of the artificial lung. The excellent antithrombogenicity, gas exchange ability, and durability of this new artificial lung with circuits might contribute to successful prolonged ECLA with minimal systemic heparinization.
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The objective of this study was to investigate the outcomes of children with heart failure of various etiologies requiring temporary use of currently available technology in the U. S. A. after extracorporeal life support (ECLS) [left ventricular assist device (LVAD) or extracorporeal membrane oxygenation (ECMO)] at Texas Children's Hospital. ⋯ The need for ECLS following repair of congenital heart disease is extremely rare in our institution. The requirement for the use of ECMO confers a significantly higher mortality presumably because of associated combined cardiopulmonary failure. Congenital heart disease appears to be associated with significantly higher mortality.
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The fluid dynamics of the Thoratec HeartMate III (Thoratec Corp., Pleasanton, CA, U. S. A.) left ventricular assist device are analyzed over a range of physiological operating conditions. ⋯ A comparison of CFD predictions to experimental imaging shows good agreement. Both CFD and experimental PIFV confirmed well-behaved flow fields in the main components of the HeartMate III pump: inlet, volute, and outlet. The HeartMate III is shown to exhibit clean flow features and good surface washing across its entire operating range.
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This article briefly discusses a few key issues related to transfusion, the concept of hemoglobin-based red blood cell substitutes (HBOCs), and some parameters useful in evaluating the current properties of solutions. Potential uses of HBOCs in civilian applications are identified and listed. Use of HBOCs as a hemodiluent for intraoperative autologous blood donation (IAD) is a particular application that has relevance in many surgical settings and this is discussed in some detail. ⋯ Extrapolation to a general use model, primarily based in the potential for surgery, will be noted. Some general parametric values of HBOCs are presented. These values are by no means considered optimal for all HBOCs and are subject to exploration, fine tuning, correction, or even rejection.
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Review
Artificial oxygen carriers as red blood cell substitutes: a selected review and current status.
Two distinct approaches are being explored in red blood cell substitute (RCS) development: hemoglobin-based oxygen carriers (HBOCs) and perfluorocarbon-based oxygen carriers (PFBOCs). HBOCs are based on intra- and/or intermolecularly "engineered" human or animal hemoglobins (Hbs), optimized for O2 delivery and longer intravascular circulation. Some are currently being evaluated in Phase II/III clinical studies. ⋯ Although current PFBOC products generally require patients to breathe O2 enriched air, they render certain advantages since they are totally synthetic. This article provides a short review of the basic principles, approaches, and current status of RCS development. Results of preclinical and clinical studies including recent Phase II/III clinical studies are discussed.