Guide extension catheter

1 . A method comprising:

introducing a guide catheter in vasculature of a patient, wherein the guide catheter extends from a guide catheter proximal end to a guide catheter distal end and defines a guide catheter lumen;

introducing a guide extension catheter in the guide catheter lumen at the guide catheter proximal end, wherein the guide extension catheter comprises:

an elongate tube member having a longitudinal axis and extending from a proximal end to a distal end and defining a guide extension catheter lumen;

a push member mechanically coupled to the proximal end of the elongate tube member;

a concave track coupled to the elongate tube member and the push member, the concave track accessible from a longitudinal side defined transverse to the longitudinal axis of the elongate tube member and defining a partially cylindrical opening and a variable degree of enclosure relative to the longitudinal axis along a length of the concave track leading into the elongate tube member, wherein the concave track comprises a proximal track portion, an intermediary track portion, and a distal track portion, wherein the intermediary track portion defines a smaller degree of enclosure around the longitudinal axis than the distal track portion and the proximal track portion such that the concave track transitions, proximally to distally, from more enclosed to less enclosed, then back to more enclosed before reaching the proximal end of the elongate tube member;

and a manipulation member slidably disposed about an outer perimeter of the push member, wherein the manipulation member is controllably engageable with the push member, wherein, when the manipulation member is in an engaged state with the push member, the manipulation member transmits an axial force to the push member to enable the push member to transmit the axial force to the elongate tube member, and wherein, when the manipulation member is in a disengaged state with the push member, the manipulation member is movable axially in at least one direction along a length of the push member while transmitting substantially no axial force to the push member;

while the manipulation member is in the engaged state with the push member, applying a distal axial force to the manipulation member to advance the guide extension catheter distally within the guide catheter lumen;

disengaging the manipulation member from the push member;

repositioning the manipulation member along the length of the push member;

engaging the manipulation member with the push member; and

while the manipulation member is in the engaged state with the push member, applying a distal axial force to the manipulation member to further advance the guide extension catheter distally through the guide catheter lumen.

2 . The method of claim 1 , wherein the push member is eccentrically coupled to the proximal end of the elongate tube member.

3 . The method of claim 1 , wherein introducing the guide extension catheter in the guide catheter lumen includes introducing the elongate tube member including a distal portion having a first diameter, a proximal portion having a second diameter that is larger than the first diameter and smaller than a diameter of the guide catheter lumen, and a tapered portion positioned between the distal portion and the proximal portion.

4 . The method of claim 1 , further comprising advancing a balloon catheter, a stent, or a stent catheter through the guide catheter and the guide extension catheter and into a coronary artery of the patient.

5 . The method of claim 1 , wherein the manipulation member comprising a tab that defines a hole through which the push member is urged during insertion of the guide extension catheter through the guide catheter.

6 . A method comprising:

introducing a guide catheter in vasculature of a patient, wherein the guide catheter extends from a guide catheter proximal end to a guide catheter distal end and defines a guide catheter lumen; and

introducing a guide extension catheter in the guide catheter lumen at the guide catheter proximal end, wherein the guide extension catheter comprises an elongate tube member having a longitudinal axis and extending from a proximal end to a distal end and defining a guide extension catheter lumen, a concave track mechanically coupled to the proximal end of the elongate tube member, a push member coupled to the concave track, and a manipulation member slidably disposed about an outer perimeter of the push member,

wherein the concave track is accessible from a longitudinal side defined transverse to the longitudinal axis of the elongate tube member and defines a partially cylindrical opening and a variable degree of enclosure relative to the longitudinal axis along a length of the concave track leading into the elongate tube member, wherein the concave track comprises a proximal track portion, an intermediary track portion, and a distal track portion, wherein the intermediary track portion defines a smaller degree of enclosure around the longitudinal axis than the distal track portion and the proximal track portion such that the concave track transitions, proximally to distally, from more enclosed to less enclosed, then back to more enclosed before reaching the proximal end of the elongate tube member,

wherein the push member includes a plurality of segments, each of the plurality of segments having a different shape in cross-section, wherein a first segment of the plurality of segments of the push member has a first shape in cross-section defined by a first arcuate surface, the first arcuate surface configured to engage an inner wall surface of the guide catheter along an arch length of the inner wall surface,

wherein the manipulation member is controllably engageable with the push member along each of the plurality of segments, wherein, when the manipulation member is in an engaged state with the push member the manipulation member transmits an axial force to the push member to enable the push member to transmit the axial force to the elongate tube member, and wherein when the manipulation member is in a disengaged state with the push member, the manipulation member is movable axially in at least one direction along a length of the push member while transmitting substantially no axial force to the push member.

7 . The method of claim 6 , further comprising:

while the manipulation member is in the engaged state with the push member, applying a distal axial force to the manipulation member to advance the guide extension catheter distally within the guide catheter lumen;

disengaging the manipulation member from the push member;

repositioning the manipulation member along the length of the push member;

engaging the manipulation member with the push member; and

while the manipulation member is in the engaged state with the push member, applying a distal axial force to the manipulation member to further advance the guide extension catheter through the guide catheter lumen.

8 . The method of claim 7 , further comprising advancing a balloon catheter, a stent, or a stent catheter through the guide catheter and the guide extension catheter and into a coronary artery of the patient.

9 . The method of claim 6 , wherein a second segment of the plurality of segments of the push member has a second shape in cross-section defined by three arcuate surfaces and one flat surface.

10 . The method of claim 6 , wherein a third segment of the plurality of segments of the push member has a third shape in cross-section defined that is a rectangle.

11 . The method of claim 6 , wherein the manipulation member comprising a tab that defines a hole through which the push member is urged during insertion of the guide extension catheter through the guide catheter.

12 . A method comprising:

introducing a guide catheter in vasculature of a patient, wherein the guide catheter extends from a guide catheter proximal end to a guide catheter distal end and defines a guide catheter lumen; and

introducing a guide extension catheter in the guide catheter lumen at the guide catheter proximal end, wherein the guide extension catheter comprises;

an elongate tube member having a longitudinal axis and extending from a proximal end to a distal end and defining a guide extension catheter lumen, and three portions, each portion having a distinct diameter, wherein a distal portion has a first diameter, a proximal portion has a second diameter which is larger than the first diameter but smaller than a lumen of the guide catheter, and a tapered portion, positioned between the distal portion and the proximal portion, has a variable diameter;

a concave track coupled to the proximal portion of the elongate tube member, the concave track accessible from a longitudinal side defined transverse to the longitudinal axis of the elongate tube member and defining a partially cylindrical opening and a variable degree of enclosure relative to the longitudinal axis along a length of the concave track leading into the elongate tube member, wherein the concave track comprises a proximal track portion, an intermediary track portion, and a distal track portion, wherein the intermediary track portion defines a smaller degree of enclosure around the longitudinal axis than the distal track portion and the proximal track portion such that the concave track transitions, proximally to distally, from more enclosed to less enclosed, then back to more enclosed before reaching the proximal end of the elongate tube member;

a push member mechanically coupled to the proximal track portion, wherein the push member includes a plurality of segments, each of the plurality of segments having a different shape in cross-section, wherein a first segment of the plurality of segments of the push member has a first shape in cross-section defined by a first arcuate surface, the first arcuate surface configured to engage an inner wall surface of the guide catheter along an arch length of the inner wall surface; and

a manipulation member slidably disposed about an outer perimeter of the push member, wherein the manipulation member is controllably engageable with the push member along each of the plurality of segments, wherein, when the manipulation member is in an engaged state with the push member the manipulation member transmits an axial force to the push member to enable the push member to transmit the axial force to the elongate tube member, and wherein when the manipulation member is in a disengaged state with the push member, the manipulation member is movable axially in at least one direction along a length of the push member while transmitting substantially no axial force to the push member.

13 . The method of claim 12 , further comprising:

while the manipulation member is in the engaged state with the push member, applying a distal axial force to the manipulation member to advance the guide extension catheter distally within the guide catheter lumen;

disengaging the manipulation member from the push member;

repositioning the manipulation member along the length of the push member;

engaging the manipulation member with the push member; and

while the manipulation member is in the engaged state with the push member, applying a distal axial force to the manipulation member to further advance the guide extension catheter distally through the guide catheter lumen.

14 . The method of claim 13 , further comprising advancing a balloon catheter, a stent, or a stent catheter through the guide catheter and the guide extension catheter and into a coronary artery of the patient.

15 . The method of claim 13 , wherein applying a distal axial force to the manipulation member to further advance the guide extension catheter distally through the guide catheter lumen further comprises advancing the guide extension catheter to a position wherein the distal portion of the elongate tube member extends beyond the distal end of the guide catheter while the proximal portion of the elongate tube member remains positioned with the guide catheter lumen.

16 . The method of claim 12 , wherein the manipulation member comprising a tab that defines a hole through which the push member is urged during insertion of the guide extension catheter through the guide catheter.