When a cardiac valve (the aortic and the mitral ones above all) is very badly deteriorated, replacing them with a prosthetic valve can be necessary. Among them, there are two perfectly differentiated types, with very specific characteristics: mechanical valves (also known as metal valves) and biological valves or bioprosthesis.
Which of them are better: mechanical or biological valves?
This question is as old as the valves, and it does not have a single answer, so we would talk about “which is the best valve” for each patient, meeting its individual features.
The reason for this particular analysis of each case is that both types bring advantages and disadvantages that must be considered when choosing one or the other. All pros and cons can be summarized in the following scheme:
Benefits or advantages of mechanical valves
The main benefit mechanical valves prosthesis is that they are made of an extremely durable material, so there is not a “erosion” (structural deterioration) despite the million and millions of beats to which are exposed.
Inconveniences or disadvantages of mechanical valves
On the other side, it is necessary to highlight that patients with mechanical prosthesis must be given blood thinners on an ongoing basis, because they must reduce the clotting of their blood, but it entails risks (hemorrhage).
The necessity of blood thinner medication is given by the blood’s tendency of thrombus development (clot) over the artificial materials surface.
Benefits or advantages of biological valves
The bioprosthesis, as made of biological material, it has as main advantage not needing blood thinners so we remove the risk resulted from this type of medication.
Inconveniences or disadvantages of biological valves
However, the less favourable aspect of bioprosthesis is that its materials are prone to deteriorate (“erosion”), so they may need a reintervention within a few years since the implantation.
It is important to highlight that Biomedical Sciences are constantly evolving and that both types of prosthetic valves keep improving over the years in the search of less thrombogenic materials in the mechanical prosthesis and tissues more resistant to erosion in bioprosthesis.
Is the TAVI valve mechanical or biological?
The prosthesis is implanted through a transcatheter which is always biological, so that it is not necessary to use blood thinners after this procedure.
The flexibility of biological tissues lets the different access routes for TAVI.