[Animal study results of a novel designed transcatheter mitral valve replacement system]

Objective: To preliminarily assess the biocompatibility and durability of the TruDelta^TM transcatheter mitral valve replacement (TMVR) system. Method: Six adult sheep were divided into 3 groups based on the duration of follow-up: 30 days (n=1), 90 days (n=3) and 180 days (n=2). The TruDelta^TM TMVR system was implanted through a transapical approach under transesophageal echocardiographic guidance. The operability of the TMVR system was evaluated using an instrument performance evaluation scale (consisting of 39 items), with scores ranging from 1 (worst) to 10 (best) assigned by the operator. Echocardiography was conducted preoperatively, immediately after surgery, and at 30, 90, and 180 days post-implantation. At the last follow-up time point, the intervention mitral valve membrane and major organs were dissected for observation. The artificial valves were taken for hematoxylin eosin (HE) staining and observed under a scanning electron microscope. Result: All six procedures were successfully completed using 29S size TruDelta^TM TMVR device. At the final follow-up, echocardiogram demonstrated good valve function without obvious paravalvular leakage, with a transvalvular gradient of (7.8±3.2) mmHg (1 mmHg=0.133 kPa) and a mitral valve orifice area of (1.8±0.2) cm². Autopsy findings revealed no structural valve failure and almost complete endothelialization (>75%) with 90 to 180 days. Both HE staining and scanning electron microscopy confirmed optimal endothelialization of the valve stent. Conclusion: The preclinical animal study indicates that the TruDelta^TM device exhibits favorable biocompatibility and durability.