Guide extension catheter assemblies, systems and methods of use

A coronary treatment system comprising:

• a guide catheter;
• a guide extension catheter assembly including:
• a guide extension catheter including:
• a shaft,
• a tubular member defining a proximal end opposite a distal end and a lumen open to the proximal and distal ends,
• wherein the shaft is coupled to the tubular member at the proximal end and extends proximally from the proximal end, and
• a support device including:
• a push member,
• a shuttle member defining a leading end opposite a trailing end,
• wherein the push member is coupled to the shuttle member at the trailing end and extends proximally from the trailing end,
• wherein the guide extension catheter assembly is configured to selectively provide a delivery state in which at least a portion of the shuttle member is disposed within the lumen, the leading end is distal the distal end, and the shuttle member is directly, physically connected to the tubular member such that a longitudinal distal force applied to the push member is transferred to the tubular member as a longitudinal distal force via the shuttle member, wherein a maximum outer diameter of an entirety of the shuttle member distal the distal end of the tubular member is not greater than a minimum diameter of the lumen in the delivery state;
• and
• an interventional coronary device.

A method of percutaneously accessing an intravascular target region, the method comprising:

• positioning a distal side of a guide catheter adjacent to an ostium of a target vessel;
• arranging a guide extension catheter assembly to a delivery state, the guide extension catheter assembly including:
• a guide extension catheter including:
• a shaft,
• a tubular member defining a proximal end opposite a distal end and a lumen open to the proximal and distal ends,
• wherein the shaft is coupled to the tubular member at the proximal end and extends proximally from the proximal end, and
• a support device including:
• a push member,
• a shuttle member defining a leading end opposite a trailing end,
• wherein the push member is coupled to the shuttle member at the trailing end and extends proximally from the trailing end,
• wherein the delivery state includes at least a portion of the shuttle member disposed within the lumen, the leading end distal the distal end, and the shuttle member directly, physically connected to the tubular member such that a longitudinal distal force applied to the push member is transferred to the tubular member as a longitudinal distal force via the shuttle member;
• advancing the guide extension catheter assembly in the delivery state through the guide catheter such that at least a region of the tubular member projects distally beyond the distal side and the leading end of the shuttle member is distally beyond the distal side, wherein the step of advancing includes the tubular member and the shuttle member moving in tandem;
• transitioning the guide extension catheter assembly from the delivery state, including removing the support device from the guide extension catheter;
• and
• advancing an interventional coronary device through the guide catheter and the tubular member.