International Circulation:  Do you think， if there is a new development or advance in the durability of biological tissue， that it will be a more promising option in the future for a greater population of patients?

Gerhard Schuler:  There are some new ideas in the pipeline， for instance a valve manufactured from 19-0， very thin， sheets and there is a possibility that there is a higher degree of durability of this valve.  If there are no further problems in development then there might be a chance for a more universal application of this valve.