The first successful kidney transplant was performed (from identical twins - ciclosporin was discovered in the 1970's, so until then the donor had to match perfectly).
If you're talking about organ transplants, it's because there were no anti-rejection drugs available on the market prior to this.
Very few, since the success rate was poor.
They happened, but no immunosuppressants were available. So the transplants generally failed. Here's a timeline: http://www.wellcomecollection.org/whats-on/events/in-or-out/transplant-timeline.aspx
The transplant development that happened in 1954 was the development of clyclosporine. This helped revelutionised the history of transplants. Actually, ciclosporin was developed in the 1970's. The 1954 development was the first successful kidney trasplant between two identical twins. (They had to be identical twins since ciclosporin had not been developed; the donor had to match perfectly).
The development of the anti suppressent drug Cylosporine by Dr.Callum Hume was the reason for the improvement in organ transplants in 1954.
No effective immunosuppression, which is required to prevent organ rejection. Corticosteroids were available (which reduce inflammation), but no calcineurin inhibitors (such as ciclosporin or tacrolimus), which alter the function of T-cell lymphocytes (a type of white blood cell, produced by the patient's bone marrow, not the transplanted organ) to prevent organ rejection. Hence most transplants failed due to organ rejection pre-1954. The first effective immunosuppression (ciclosporin) was found in the 1970's, but 1954 happened to be the year when the process of organ rejection was first understood.
The first successful kidney transplant between two twins. Proved that it was possible and aided in the understanding of 'rejection'.
Partition of Vietnam happened in 1954.
Kidney transplants, followed by liver transplants, are most common.
Kidney and liver are the two most commonly transplanted organs (excluding those which happened before 1950)
Transplants - band - was created in 1999.
Yes, heart transplants are commonly performed.