The concept of a fully living autologous valve replacing the diseased aortic valve gives the hope of a normal life span of durability since it can grow and replenish its cellular architecture and matrix elements the way the native aortic valve would normally do. The only question was whether the pulmonary leaflets could stand up to the higher pressures on the left side of the heart. Considerable engineering analysis has been done over the years to prove that the pulmonary valve can indeed withstand these stresses and remodels itself to adjust to this situation. The very first autograft implanted in 1967 was still working over 35 years later.
The substitute valve on the right side of the heart is usually a pulmonary homograft which has been shown to be free of reoperation in 85% of patients 20-25 years after implantation. The lower pressures in the right ventricle and pulmonary artery put far less strain on the donor valve. Regardless of the method of preservation, homografts last longer on the right side than the left. Furthermore, if the valve on the right side becomes incompetent (develops regurgitation) the consequences are much better tolerated allowing many more years before replacement is needed.
In summary, the Ross Procedure is the only tissue valve operation that has the possibility of lasting as much as 40 years without blood thinners and without reoperation. That does not imply that all willl do so as some patients will inevitably require further surgery along the way as is true for any valve substitute. As we have learned more and more about the behavior of the pulmonary valve and artery in the aortic position as well as about the intrinsic nature of the aorta itself, improvements have been developed to prevent the dilatation that can precipitate failure of the autograft over time.