The present disclosure, in its various aspects, is directed generally to medical devices, and more specifically to catheter accessory devices and related systems and methods. In an embodiment, an instrument accessory device may include a body with an instrument lumen through which an instrument may extend through. An expandable member may be disposed about the distal end of the body. An elongate delivery member may be attached to the body and in communication with the expandable member at a distal end of the delivery member. The delivery member may be configured to slide the instrument lumen of the body and the expandable member along the length of the instrument when extended therethrough. Other embodiments are addressed within.