THE FIRST DOMESTIC IMPLANTABLE AXIAL FLOW PUMP: RESULTS OF EXPERIMENTAL STUDIES IN CALVES

Aim of our experimental study was evaluation of the first domestic implantable axial pump as a left ventricle assist device in calves. Materials and methods. 18 calves 90–120 days of age, weighing 95 ± 5 kg were exposed to implantation of an axial pump under the scheme «left ventricular – aorta» in paracorporeal and implantable in chest cavity versions. Two models of the pump were tested. Model 1 is a pump with cylindrical bearings and elongated straightener, model 2 had ball bearings and modified design of impeller and straightener. Results. In the first series (n = 12) the pump model 1 was tested. The duration of experiments was 4,9 ± 5,3 days, maximal duration was 16 days. The experiments were finalized due to intraoperation cardiac fibrillation (n = 3), uncrop- ped acute bleeding (n = 3), lowering of blood flow through the pump of 60 ± 15% (n = 6) because of thrombo- sis of the pump (n = 5) and outlet line (n = 1), in 3 cases of 5, combined with mechanical wear of bearings. In the second series (n = 6) the pump model 2 was tested. In 4 experiments of 6 the duration was 74,5 ± 29 days. One experiment was finalized due to intraoperation cardiac fibrillation. Another one experiment was finalized on 8 day as planned. In 5 experiments there was absence of either thrombosis or mechanical wear of bearings. Morphological and histological examination of the kidneys, liver and lungs in the 5 experiments of second series did not reveal the presence of zones of ischemia or thromboembolia. Conclusion. The results of the second series can be treaded as preclinical testing of the first domestic implantable axial pump as a left ventricle assist device in calves