The results of the application of a new technique of open implantation of self-opening transcatheter aortic valves in an experiment

Background. In recent years, transcatheter implantation of the aortic valve has become increasingly performed as an alternative to "open" prosthetics. The undoubted advantage of this technology is its minimally invasive nature, which in most cases provides a favorable clinical outcome of the intervention. The transcatheter method of aortic valve prosthetics does not require sternotomy and connection of an artificial circulation device, which significantly reduces the risk of postoperative mortality and complications. However, despite all the advantages of the existing models, they are not without drawbacks that force researchers to develop and test new transcatheter valves. The problem of experimental studies of new models of self-opening transcatheter aortic valves is mainly determined by the anatomical features of the aortic root of animals. In this regard, the development of a reliable method of implantation of valve prostheses in the experiment is an urgent problem of preclinical testing. Aim. Development of a protocol for open implantation of a transcatheter aortic valve in experiment and evaluation of long-term results. Methods. To develop an experimental model, pigs of the "Landras" breed, females weighing 129.83 ± 9 kg were used. Transcatheter aortic valve implantation was performed under conditions of artificial circulation and moderate hypothermia (33-34°C) through a transverse aortotomy under the control of vision. During the experiment, invasive monitoring of blood pressure, central venous pressure, heart rhythm, body temperature, blood gas composition, activated clotting time was performed. The correct positioning and hemodynamic parameters after implantation were evaluated using transesophageal echocardiography. Results. In a series of chronic experiments, 18 open implantations of self-opening transcatheter aortic valves were performed. Successful positioning was achieved in 100% of cases. The developed protocol of open implantation made it possible to achieve reliable fixation of the prosthesis in the orthotopic position, as well as to prevent the migration of the prosthesis, the development of mitral regurgitation, paraaortic fistulas and coronary circulation disorders. Conclusion. In the course of the study, a simple and effective method of open implantation of a transcatheter aortic heart valve prosthesis was developed in an experiment.