Apparatus for use in conjunction with implanting a collapsible and re-expandable prosthetic heart valve in a patient by means that are less invasive than traditional open-chest, open-heart surgery. The apparatus may include a one-way valve for preventing blood from escaping from the patient's circulatory system when that system is entered in order to get the prosthetic heart valve into that system. The apparatus may include various forms of cutters for gaining access to the patient's circulatory system. The apparatus may include various forms of devices for quickly closing the access to the patient's circulatory system after the prosthetic heart valve has been implanted.