Many medical factors need to match to ensure a successful organ transplant. Blood group is one of the major factors taken into account. Organ size of the donor & recipient is also considered. For kidneys another important factor is tissue matching which is more complex than blood grouping matching and also takes more time. The best results can be achieved if there is a perfect kidney match.
There is a local, regional and national computerized list of patients waiting for an organ transplant. Most of the time, computer will identify the best matched patient for a particular organ and organ is offered to the transplant unit who is treating that patient. Also, priority is given to patients who most urgently need a transplant. NOTTO operates the waiting list and organ allocation system. It works round the clock, every day of the year. In case of tissues, matching is usually not required.