A system can include a handle and a needle fixedly secured to the handle. The needle can include a distal tip that can be inserted through a sidewall of a vessel of a patient. The system can further include a catheter that defines a lumen through which the needle extends and includes an engagement surface at an interior thereof. A cannular stiffener can be positioned within the lumen of the catheter at an exterior of the needle and can include an engagement surface that can press distally on the engagement surface of the catheter to advance the catheter distally over the needle and through a lumen of the vessel when the stiffener is advanced distally over the needle. The system can further include a stiffener hub attached to the stiffener, the stiffener hub being movably coupled with the handle so as to translate relative thereto. The stiffener hub can be configured to move distally relative to the handle from a retracted position to a deployed position to advance the stiffener and the catheter over the needle and to a target depth within the lumen of the vessel as the handle is held stationary relative to the vessel.