DUAL VALVE REINFORCED SHEATH AND METHOD

摘要

A large diameter expandable sheath (11) for use in introducing a catheter or other medical instrument into a vessel in the body of a patient. The expandable sheath (11) comprises an elongate sheath tube (12) formed of a flexible material which has proximal (13) and distal (14) extremities and a passage (16) therethrough of a maximum predetermined diameter. The distal extremity (14) of the elongate sheath tube (12) is folded longitudinally to a smaller folded diameter. The sheath tube (12) may be self-expanding or may be reinforced with a self-expanding wire or expandable stents (19). A backflow adaptor (21) is secured to the proximal extremity (13) of the elongate sheath tube. A normally closed primary valve (40) is disposed in the central opening (23) of the backflow adaptor (21) and is movable to an open position. A normally open secondary valve (150), movable to a closed position, may be configured in the backflow adaptor (21) proximal the sheath tube (12) and distal the primary valve (40).