I found this interesting…..., page-21

"The Expected life of a replacement tissue valve is approx 15 years.".....just did a quick search..

.from http://www.onxlti.com/message-to-patients/tissue-or-mechanical-heart-valve/...........

"The lifetime of a tissue valve is typically 10 to 15 years, often less in younger patients. Over this time the valve will likely be degenerating to the point of requiring replacement. Because valve replacement surgery carries a significant risk of death, patient life expectancy is a major criterion in considering a tissue valve."

IMO, ahz's technology is a substantial improvement on what is currently available.

Again from the same site.

" Mechanical valves are preferred for patients with life expectancies beyond 10-15 years because they eliminate the mortality risk inherent in the replacement of a worn out tissue valve."

reinforces ahz technology again plus given an ageing population my educated guess is that tissue valve replacement will be increasingly used/preferred in the future

and again..

"Valve selection is a balancing act between the major positives and negatives of both valve types:

• The limited durability of tissue valves (performance degradation and the stress or mortality of reoperation).
• The requirement for lifelong anticoagulation therapy of mechanical valves."

To simply dismiss an argument based on ones own experience is a bit like belief that the world was flat