A method involves positioning an assembled indwelling assembly adjacent a patient, wherein the assembly includes an inner needle, a hub fixed to the inner needle, a hollow outer member in which the inner needle is positioned, a hub fixed to the hollow outer member, and an elongated member axially overlapping an intermediate portion of the hollow outer member. The method also includes moving a distal portion of the assembly to puncture a blood vessel of the patient with the sharp needlepoint while the elongated member contacts the hollow outer member, advancing the hollow outer member in a distal direction along the inner needle to insert a distal portion of the hollow outer member to a target position in the blood vessel, and moving the inner needle hub in a proximal direction such that the inner needle is pulled out from and entirely removed from the hollow outer member.
