Donor kidney. Surgeon removing a donor kidney from its outer plastic bag in preparation for a transplant operation. Kidneys can be kept alive for several days outside the body by keeping them cool and sterile. Kidney transplantation is the simplest and most commonly performed organ transplant, and it has a very high success rate. It is done to replace kidneys with chronic kidney failure. Kidneys must have their fat removed, their blood vessels prepared and be flushed with perfusion fluid prior to transplantation. This view is part of image sequence M575/050-56 showing a kidney being prepared for transplantation.