Apparatus and methods for extracorporeal blood filtration involving the connection of a patients cardiovascular circulation to an extracorporeal circulatory circuit, and filtration devices suitable for use in such apparatus and methods are disclosed. Such filtration devices include a filter medium comprising a layer of non-woven fabric (21) impregnated with porous beads (22) and carrying a porous screen (23) on at least one side. This invention enables the removal or particular molecular species such as pro-inflammatory cytokines from a patients circulation, and is of particular utility in cardiopulmonary bypass and haemodialysis-like procedures.
