Objective To develop a novel transcatheter tricuspid valve replacement device and test its performance. MethodsThe transcatheter tricuspid valve stent consisted of double-layer self-expanding nitinol stent, biotissue-derived bovine pericardial leaflets, and PTFE woven. The delivery system, mainly consisting of a handle control unit and a delivery sheath, was sent to the correct position via right atrium or jugular vein. The sheath had a visualization feature, and the handle control unit could realize the functions of stable release and partial recovery of the interventional valve. In addition, this study performed animal survival experiments on the basis of in vitro experiments. A large-white pig was used as the experimental animal. Cardiopulmonary bypass was established through median thoracotomy, then the right atrium was opened, and the interventional valve was released under direct vision without cardiac arrest. Approximately 1 month after interventional valve implantation, the maneuverability and stability of the interventional tricuspid device were evaluated by autopsy. ResultsThrough the animal experiment, the interventional valve was successfully released, and the anchoring was satisfactory. Postoperative transthoracic echocardiography showed that the interventional valve opened and closed well, the flow rate of tricuspid valve was 0.6 m/s, and there was no obvious tricuspid regurgitation. One month after the operation, we dissected the large-white pig and found the interventional valve was not deformed or displaced, the leaflets were well aligned, and there was thrombus attachment in the groove between the inner and outer layers of the interventional valve. ConclusionAnimal experiment shows that the novel device can stably and firmly attach to the tricuspid annulus, with good anchoring effect, and effectively reduce paravalvular leakage.
Mitral valve replacement is one of the most common heart valve surgeries in China. In recent years, with the increase in degenerative valve diseases, older patients, and the progress of anti-calcification technology of biological valves, the proportion of mitral valve biological valve replacement has been increasing year by year. After the damage of traditional mitral valve biological valves, re-operation of valve replacement with thoracotomy is required. However, the adhesion between the heart and sternum, as well as the damage caused by cardiopulmonary bypass and cardiac arrest, can cause significant trauma to elderly patients and those with multiple organ dysfunction, leading to increased mortality and complication rates. In recent years, interventional valve surgery, especially transcatheter valve-in-valve surgery, has developed rapidly. This procedure can correct the damaged mitral valve function without stopping the heart, but there are still many differences between its technical process and conventional aortic valve replacement surgery. Therefore, organizing and writing multicenter expert recommendations on the technical process of transcatheter valve-in-valve surgery for damaged mitral valve biological valves is of great significance for the training and promotion of this technology.