Animal experimental study on the safety and effectiveness of domestically produced miniature implantable left ventricular assist device

Xu Can; Yang Guang; Wang Dongjin; Liao Yunyan; Yu Shunzhou; Wei Xufeng

doi:10.3760/j.issn.1673-4777.2024.02.005

Abstract：Objective To test and study the safety and efficacy of a self-developed domestic implantable magnetic levitation left ventricular mechanical circulatory assist device(Corheart 6)through in vivo implantation experiments in animals.Methods Ten normal level male healthy adult sheep were selected,and after conventional general anesthesia,the left side of the 5 th intercostal space was opened to establish extracorporeal circulation and implanted with Corheart 6 with pump size 34 mm × 26 mm and weight 90 g.Corheart 6 was connected to the left ventricle and descending aorta for left ventricular assist.Postoperatively,extracorporeal circulation was withdrawn and the animals were continuously monitored for vital signs and Corheart 6 operation status.Heparin intravenous infusion maintains activated coagulation time＞500 s.The overall survival and blood compatibility of the animals were observed and cardiac anatomical and pathological analysis was conducted at the end of the experiment.Results All 10 sheep resumed beating after surgery and were successfully withdrawn from the extracorporeal circulation.Eight animals survived normally to the expected experimental endpoint(61-65 d),2 animals did not reach the experimental endpoint,including 1 case in which myocardial tissue accidentally entered the blood pump and terminated the experiment early,and 1 case died 23 d after surgery due to pulmonary hemorrhage,the cause of death was pulmonary hemorrhage,which was related to anticoagulant drugs.The Corheart 6 pump used in the experiment ran well,and there were no shutdowns or other operational failures caused by its own reasons throughout the entire experiment.No significant hemolysis was found in the experimental animals,and the overall blood indicators were within the normal range,with no significant abnormalities found.The dissected hearts of 8 surviving experimental sheep at the end of the experiment were of normal size and morphology,with no obvious bleeding points or thrombosis,and the other organs were also basically normal.There was no thrombus formation at the inlet of the blood pump,and there was no obvious thrombus formation or tissue deposition inside the pump body or at the pump outlet.The inlet pipe was tightly connected to the apical ring without looseness,and the vascular protective sleeve was well connected to the pump outlet.The artificial blood vessel was well aligned with the aortic segment.Conclusion In this animal experimental study,Corheart 6 demonstrated small size,easy implantation,stable performance,good hemodynamic effect and good hemocompatibility.