Is Tri-leaflet valve better than Bi-leaflet valve?

Background:

The mechanical valve prostheses currently in clinical use are designed as Bi-Leaflet valves comparing to Tri-leaflet Bio- prostheses or native valve. While mechanical prostheses are superior to Bio-prostheses in terms of durability, they are prone for thromboembolic complications, requiring lifelong anticoagulation therapy, which might produce significant complications and have negative impact on quality of life.

We designed an innovative mechanical prosthesis as a Tri-leaflet valve and tested its flow hemodynamic properties comparing to a Bi-leaflet one.

Methods:

Our group identified several factors, which influence valve durability and thromobogenicity potential. Turbulent flow reduces flow efficiency and increases in vivo risk for thrombus formation. Electrostatic forces, and imperfect surface smoothness of valve devices facilitate precipitation of blood components onto valve components thus promoting thrombus formation on valve surfaces.

Using CFD (computational flow dynamics) technology, with fluid properties similar to blood, we tested several flow changing elements, which optimize flow through our proprietary, newly designed prostheses.

Our innovative valve is composed completely of ceramic material in order to eliminate any electrostatic forces and create perfect surface smoothness.

Additional innovative features include the incorporation of a novel valve closure mechanism, to provide a valve closing that is rapid and reliable thus minimizing regurgitant volume.

Results:

Bi-leaflet prosthesis was superior to Tri-leaflet when comparing turbulence volume but adding flow changing elements to the Tri-leaflet model, significantly improved its performance. Pressure gradients were comparable.

The Tri-leaflet design provides an advantage in implementing a closing mechanism and future adaptation to percutaneous delivery

Conclusions:

Flow through Tri-leaflet designed valve demonstrated flow properties comparable to standard devices, although turbulent flow is still a challenge for improvement. Additional innovative elements comprising this new valve technology are still being validated in an ongoing testing.