"Replacement organs" refers to organs that are used to replace a person's damaged or malfunctioning organ with a healthy one, typically through transplantation. Full definition
The embryonic cells can develop into replacement organs in the lab or be injected into an egg, where they develop as a viable embryo and are literally born. (discovermagazine.com)
One day, making a pig of yourself could have a whole new meaning with the advent of animals bred to provide us with replacement organs if we need them. (newscientist.com)
In the more distant future, scientists might be able to grow whole replacement organs that our bodies will not reject. (scientificamerican.com)