Transplanted kidneys get rejected by the recipient's immune system eventually, you'd really need to clone the kidney from the individual's DNA to solve the rejection problem. There's also been some success with integrating the DNA from the kidney donor (a human) into the recipient's bone marrow to stop the rejection process, but I hear it can be a brutal procedure in which the original bone marrow must be destroyed using chemotherapy or radiation.
https://newsnetwork.mayoclinic.org/discussion/video-eliminat...
https://www.immunofree.com/how-it-works/
If I were a patient, I'd probably want a pig kidney now and really hope it lasts until something like kidney cloning is a thing.