What is the bottleneck to organ donation? 46 out of 1 million seems atrocious, not laudable. How many people are willing to donate but medically unable?
They main bottleneck besides opt-in laws in some countries are the average age of the deseased. You really want young healthy accidental deaths, car or motorcycle accidents are the best. You don't that care much about older organs of sick people.
The second most important factor is good organization and infrastructure. That's Spain's and now also Croatia's strength. You really need to be able to transport the organ fast and cool to the next hospital where the organ is needed. And you need to have the recipient on call also, who should not have eaten something in the last 6 hours.
You cant tell until it comes to it I had a kidney transplant last year and only one kidney was usable. I was the better match - so the guy on the bed next to me had to be told sorry and had to go home
Also some kidneys can be problematic I passed on one where the donor might have been HIV+ - I had gone on the list prior to needing diyalsis so it wasn't like I needed one immediately.
The second most important factor is good organization and infrastructure. That's Spain's and now also Croatia's strength. You really need to be able to transport the organ fast and cool to the next hospital where the organ is needed. And you need to have the recipient on call also, who should not have eaten something in the last 6 hours.