Wiktionary
n. (context medicine English) A blood transfusion in which a person receives their own blood, extracted previously.
Wikipedia
Autotransfusion is a process wherein a person receives their own blood for a transfusion, instead of banked allogenic (separate- donor) blood. There are two main kinds of autotransfusion: Blood can be autologously "pre-donated" (termed so despite "donation" not typically referring to giving to one's self) before a surgery, or alternatively, it can be collected during and after the surgery using an intraoperative blood salvage device (such as a Cell Saver or CATS). The latter form of autotransfusion is utilized in surgeries where there is expected a large volume blood loss - e.g. aneurysm, total joint replacement, and spinal surgeries.
The first documented use of "self-donated" blood was in 1818, and interest in the practice continued until the Second World War, at which point blood supply became less of an issue due to the increased number of blood donors. Later, interest in the procedure returned with concerns about allogenic (separate-donor) transfusions. Autotransfusion is used in a number of orthopedic, trauma, and cardiac cases, amongst others. Where appropriate, it carries certain advantages - including the reduction of infection risk, and the provision of more functional cells not subjected to the significant storage durations common among banked allogenic (separate-donor) blood products.