Abstract: An adaptor for use in a blood conduit of an extracorporeal life support system. The adaptor includes a body defining a main passageway and an auxiliary port extending from the body with a passageway of the auxiliary port converging with the main passageway. The auxiliary port includes a hemostasis valve configured to selectively seal around a medical device inserted through the auxiliary port into the main passageway. An elastomeric valve may be positioned in the passageway of the auxiliary port spaced away from the hemostasis valve such that elastomeric valve is located between the hemostasis valve and the main passageway. In some instances, the hemostasis valve may be removably couplable to the auxiliary port.