[rurban]

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.