Removal of the SPLEEN. This operation may be necessary if the spleen has been severely injured, or in the treatment of the severe form of acholuric JAUNDICE or autoimmune thrombocytopenic PURPURA. Removal of the spleen renders a person susceptible to certain serious infections, such as pneumococcal sepsis; such persons need pneumococcal vaccine and may have to take penicillin for some years after operation (especially if removed in childhood).