Flexible Textile Heartvalve Prosthesis: An In Vitro Evaluation

The hydrodynamic performances of fabric heartvalve protheses were measured and compared with other commercially available types of heartvalve prostheses. A prosthesis was manufactured by forming fabric to a geometry close to that of the native valve. In vitro performances of the prototype were evaluated using a pulse duplicator simulating the left side of the human circulatory system, with a 70 ml cardiac output at a constant heart rate of 70 beats/min under a mean diastolic pressure of 100 mmHg. Woven fabrics of different weaves, yarn structures (multifilaments and microfibres), saturation indexes, and rigidity were tested in terms of static and dynamic regurgitation, pressure drops across the valve, and dynamic behaviour. The results were found to be close to those expected for such a device and, in some respects (pressure drop), even better than those obtained with other prostheses in current use. The yarn structure and fabric saturation index seem to be important parameters in the development of a textile prosthesis. Thus, the tests showed that a plainweave structure with microfilament yarns and a reduced saturation index appears to be the fabric best suited for the valve application.