[Organ allocation system: between efficiency and equity].

Despite considerable efforts to promote organ donation and increase the amount of organ retrieval, demand for grafts is increasing and remains much higher then availability. This short supply is noticeable for all organ transplantation whether for heart, lungs, liver or pancreas but mainly for kidneys. The objective of graft allocation and attribution rules is to insure an allocation as fair as possible, to find the best recipient, to take into account the emergency of the need for grafting or the access difficulty for certain patients, and to seek optimal graft usage. These rules are based on the setting up of priority categories for patients whose lives are threatened on a very short-term basis or for those having difficult access to transplantation. This implies the issue of seeking the balance between an allocation as fair as possible and technical constraints associated with organ retrieval, transportation and graft quality preservation.