Catheter system

A method comprising:

• introducing a guidewire within vasculature of a subject;
• advancing an elongate catheter along the guidewire, the elongate catheter defining a longitudinal axis, a first lumen, a second lumen, and a third lumen;
• securing the guidewire to the elongate catheter, wherein securing the guidewire comprises securing the guidewire with a fastening structure positioned within the second lumen or the third lumen, wherein the fastening structure is configured to selectively engage the guidewire to secure the guidewire with respect to the elongate catheter such that movement of the guidewire causes deflection of the elongate catheter with respect to the longitudinal axis;
• and
• manipulating the guidewire to cause deflection of the elongate catheter.

A catheter system comprising:

• an elongate catheter defining a longitudinal axis, a first lumen, and a second lumen, the elongate catheter comprising a leading catheter end segment and an inner wall positioned between the first lumen and the second lumen, wherein the first lumen and the second lumen each extend at least partially through the elongate catheter to the leading catheter end segment;
• a guidewire configured to be positioned within the first lumen, wherein the guidewire and the elongate catheter are movable relative to each other;
• and
• a fastening structure configured to be positioned within the second lumen, wherein the fastening structure is configured to secure the guidewire to the elongate catheter such that movement of the guidewire causes deflection of the elongate catheter with respect to the longitudinal axis, the fastening structure being configured to secure the guidewire relative to the elongate catheter by at least causing deflection of the inner wall such that the inner wall engages the guidewire or by at least drawing the guidewire toward the fastening structure such that the guidewire engages a surface of the inner wall.