It tends to be system based although there is some cross-over.
Heart and lung transplants tend to be done by CT surgeons who have done additional training.
Renal transplants are typically done by Abdominal Transplant surgeons, although some Urologists do them as well.
Liver transplants are done by Abdominal Transplant Surgeons, although some Hepatobiliary surgeons will do them.
So yes, there are Heart and/or Lung transplant fellowships to be done after General Surgery and CT surgery, and Abdominal Transplant fellowships to be done after General Surgery.
Adominal Transplant training gives you experience in liver, panc, small bowel and kidney usually. There are Hepatic Transplant fellowships and Renal Transplant stand-alone fellowships as well.
I am not aware of "neuro transplant" fellowship as, last I heard, brain transplants didn't work so well.
😉
See
www.asts.org for more information.