Aphaeresis

noun

1. Elision, suppression, or complete loss of a letter or sound (syllable) from the beginning of a word, such as the development of special from especial; procope.
2. (specific, still current) The removal of blood from a patient, and the removal of certain components (such as platelets) from that blood, followed by the transfusion of the filtered blood back to the donor (patient).
3. (general) Extirpation or extraction of a superfluity (especially a pathological one) from the body, especially blood.