Biomedical subjects
Publications and source records attributed to V N Eremin.
The authors propose a design of an axial shovel pump for extracorporeal circulation. They show how to introduce it into various cardiovascular segments and make a comparative assessment of its efficacy in relation to the type and severity of heart failure, surgical access, and treatment policy.
Experiments were conducted on 26 mongrel dogs and 10 calves to evaluate the effect of uni- and biventricular bypass created by means of artificial heart ventricle on hemodynamics in acute cardiovascular insufficiency (ACVI) and heart arrest (HA). The use of unilateral right-ventricular (RVB) and left-ventricular bypass (LVB) was shown to be equivocal: in sufficient functional reserve of the left-ventricular myocardium the volume blood flow in the aorta was increased to a greater degree by RVB (to 2.1 +/- 0.3 l/min) than by LVB (to 2.0 +/- 0.5 l/min). Experiments during HA allowed the authors to evaluate selectively the bypasses in maintenance of the systemic blood flow. It was found that in univentricular bypass the other half of the heart had an effect on hemodynamics, which depended on the initial hemodynamic parameters of the divisions of circulation with high and low pressure, the filling of the heart cavities with blood, and the effect produced through the interventricular septum. The increase of the volume blood flow in the aorta in RVB to 0.6 +/- 0.1 l/min is linked to a great measure by the authors with the conducted artificial ventilation of the lungs. It was noted that the greatest difficulties in maintaining the systemic blood flow in ACVI were associated with the development of disproportion of the contractile function of the right and left parts of the heart. With consideration for this circumstance, the indications for univentricular bypass are determined. A clinical case with prolonged use of LVB (8 days) is discussed.
Hydrophilic gels were made using methyl methacrylate and N-vinylpyrrolidon. Simple designs of hydrophilic gels (films, tubes) for the in vitro studying of thromboresistant properties were manufactured. On the base of measurements of blood clotting time, concentration of prothrombin complex factors fibrinogen, heparin, thromboelastography, and thrombocyte adhesion onto hydrogel surface in blood contact; it was demonstrated that a hydrophilic gel consisting of 86 mol% of methyl methacrylate, 14 mol% of N-vinylpyrrolidon and 0.652 mol% of hydrolysed N-vinylpyrrolidon has optimum thromboresistant properties. Thromboresistant was studied in the dogs during 44 operations, in which both the aorta and peripheral vessels replaced by polypropylene prostheses or by Lavsan, modified by the addition of hydrophilic gels, were applied. It was shown that hydrophilic gels decrease thrombogenesis and promote rapid endothelialization and periprosthetic tissue vascularization.
Thrombogenic resistant polyelectrolyte compositions were obtained on the basis of weak polyelectrolytes used in different quantity proportions. The investigations were performed in vitro on rabbit blood and in vivo on 21 dogs and 5 calves in the conditions of acute and chronic experiments. The optimal compositions of polymers were selected for the implantation. The appropriate polyelectrolyte compositions on the basis of weak polyelectrolytes, and polymers modified by polyacryl acid with polyethylene piperazine (1:1, 2:1, 3:1), were found to be thrombogenic resistant and did not cause any significant blood cells damage. The investigations performed the possibility for their practical application.
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The authors offer a system for auxiliary circulation (a "hybrid man-made heart"), review design varieties, describe the functioning of the system. The paper is of interest for designers of the systems for extracorporeal circulation and for practicing physicians concerned with the problems of cardiology.
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Explore the source record for details and available documents.