Introduction.One of the main indicators characterizing mechanical circulatory support devices (artificial valve, implantable pumps, etc.) is trauma of blood cells. Therefore, while developing new pumps, one of the key studies in vitro is to evaluate blood hemolysis. For an objective hemolysis analysis of pump it is required to create a standardized methodology of hemolysis studies. The object of the study in this paper is implantable axial pump DON for two-step heart transplantation in children.The aimof study is to develop a standardized methodology of hemolysis studies of blood pumps and to conduct research of pediatric axial pump DON.Materials and methods.To conduct hemolysis research we created a mock circulatory system consisting of a reservoir placed in water bath maintaining a constant working fluid (blood) temperature, hydrodynamic resistance, connecting tubes, ports for blood sampling and pressure and flow measurement systems, and research pump. Test method is to estimate levels of free hemoglobin pHb obtained by blood samples during pump working in operating mode (for pediatric pump: blood flow 2.5 l/min, pressure difference 80 mmHg). Using the data obtained the standardized indices of hemolysis NIH and MIH are calculated based on pHb values, hematocrit, total hemoglobin, blood flow and working pump time.Results.We developed and realized a standardized methodology of hemolysis research by which we evaluated hemolysis of pediatric axial pump. The results of hemolysis tests allowed us to optimize the design of DON. Obtained values of hemolysis of the latest version of pediatric pump DON-3 have shown that they do conform to the requirements of minimum blood injury and it allows us to proceed to the next step of pediatric pump research – animal experiments.Conclusion.Developed methods and evaluation tools of hemolysis allow us to provide objective information on one of the most important indicators of developing implantable pediatric axial pump and they could be recommended for hemolysis research of others pumps.

Aim.To evaluate the functioning of an implantable pediatric axial pump «DON-3» for bypassing the left ventricle of the heart in experiments on sheep.Materials and methods. Five sheeps at the age of 12–18 months performed paracorporeal installation of the children’s axial pump «DON-3» according to the scheme «left ventricle – aorta».Results.A technique was developed and 5 chronic experiments were conducted on sheep to assess the model of the children’s axial pump «DON-3». The duration of the experiments in this series averaged 9 ± 5 days. The main indicators of hemodynamics, acid-base balance were within the norm. Conducted morphological and histological studies of the kidneys, liver and lungs did not reveal the presence of zones of ischemia and thromboembolism.Conclusion.The results of this series of experiments showed satisfactory results, suggesting further research on the development of prototypes of a pediatric pump for clinical practice.

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Информация о финансировании. Исследования проведены при финансовой поддержке ФГБУ «3-й ЦВКГ им. А.А. Вишневского» МО РФ. Конфликт интересов. Все авторы сообщают об отсутствии конфликта интересов.

We have developed and tested a technique for constructing 3D models of the chest and thoracic cavity organs. Due to the obtained results, the mathematical model  was successfully used in the development of classification of variants of placement  of implantable auxiliary circulation systems, and also for building 3D models for  other purposes. In particular, the patients were graded according to the variants of  placing the children’s axial pump DON-3 inside the patient’s chest cavity. Based on  the data, the first fitting of the DON-3 pump was performed on a patient aged 7 years.