Establishing a Novel Animal Model of Tricuspid Regurgitation by Self-expanding Stent

AIM: To establish a simple, safe, and reproducible animal model of tricuspid regurgitation (TR). METHODS: A self-expanding stent made of nickel-titanium shape memory metal alloy was developed. Ten white pigs were randomized into an experimental group (n = 7) and a control group (n = 3). TR was induced by an interventional procedure by implanting a self-expanding stent via the internal jugular vein (IJV) to open the tricuspid valve in the experimental group. The pigs in the control group underwent the same procedure without stent implantation. Echocardiography was performed preoperatively and at 1 month and 3 months postoperatively to assess cardiac function and structure modification. RESULTS: Echocardiography displayed enlargement of the right atrium (RA) and tricuspid annulus, as well as reduced right heart function in the experimental group. Additionally, the TR area (p < 0.01), TR/RA (p < 0.01), RA (p < 0.05), and tricuspid annulus (p < 0.01) were significantly higher at 1 month or 3 months postoperatively compared with preoperative values. Likewise, right ventricular Tei index (RVTei) (p < 0.05) was significantly increased. However, right ventricular fractional area change (RVFAC) (p < 0.05), and tricuspid annular plane systolic excursion (TAPSE) (p < 0.05) were decreased, indicating impaired right heart function. Moreover, no significant changes were noted in the body weight of white pigs. All pigs survived, validating the successful establishment of the TR model. Notably, both the success rate and the survival rate were 100% in the experimental group. However, right heart remodeling was observed in the experimental group. Finally, no significant changes were detected in the control group before and after the operation. CONCLUSIONS: Self-expanding stent implantation via IJV is a simple and easy-to-manipulate approach for constructing an animal model of TR, which is suitable for exploring right ventricular remodeling.