Variable stiffness guidewire

• US 5,957,903 A
• Filed: 11/25/1997
• Issued: 09/28/1999
• Est. Priority Date: 10/15/1991
• Status: Expired due to Term

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Mirzaee, Daryush, Tremulis, William Stephen
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): RUHL, DENNIS WILLIAM
• Application Number:
  US08/976,444
• Time in Patent Office: 672 Days
• Field of Search: 128/772, 604/95, 604/280, 604/282
• US Class Current: 604/524
• CPC Class Codes: A61M 2025/09083 having a coil around a core
• CPC Class Codes: A61M 2025/09091 where a sheath surrounds the coil at the distal part
• CPC Class Codes: A61M 2025/0915 having features for changing the stiffness
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: A61M 25/09033 with fixed mandrils, e.g. mandrils fixed to tip; Tensionable wires

Abstract

Using a variable stiffness guidewire to cross a stenosed region of a patient'"'"'s vasculature by advancing the distal end of the guidewire to the stenosed region, reducing the flexibility of the distal end of the guidewire, and further advancing the distal end through and past the stenosed region of the lumen. The variable stiffness guidewire has a longitudinally movable core member with a proximal end and a shapable distal end, a compressible body is slidably mounted on the core member, with one end of the compressible body secured to the end of the core member, and a tubular support member is disposed about the core member with a distal end that abuts the proximal end of the compressible body. The guidewire further comprises a tensioning means at the proximal end to move the core member longitudinally with respect to the tubular support member so as to compress and reduce the flexibility of the compressible body.

Claims

1. A torqueable guidewire having a shaped distal section with adjustable flexibility comprising:

a) an elongated longitudinally movable core member having a shaped distal extremity, a proximal extremity, and a longitudinal axis extending through the core member wherein the core member is configured to transmit torque from the proximal extremity to the distal extremity;

b) a center coil which has a distal end and a proximal end and which is disposed around the distal extremity of the movable core member and which is affixed to the movable core member at the distal end and proximal end;

c) a helical coil having a length axially adjustable by compression and expansion, a flexibility relative to its length, a proximal portion, and a distal portion secured to the distal extremity of the longitudinally movable core member, wherein the helical coil is disposed about the center coil which is disposed around the core member and said helical coil is slidable with respect thereto;

d) a shapeable distal section including the distal extremity of the movable core member, the center coil, and the helical coil, adjustable from a flexible shaped condition where said distal section is in an orientation that is not coaxial with a portion of the core member proximal to the distal section to a straightened stiffer condition where said distal section is in an orientation that is coaxial with a portion of the core member proximal to the distal section;

d) an elongated tubular support member which has a proximal end and a distal end and which is disposed about the longitudinally movable core member and proximal to the helical coil, which is slidable with respect to the core member and which has the distal end configured to support the proximal portion of the coil; and

e) a tensioner connected to the proximal end of the tubular support member configured to apply tension to the core member and substantially uniformly adjust the compression and axial length of the helical coil and stiffen the distal section of the guidewire and straighten the distal section to an orientation collinear with the core member longitudinal axis, by effecting relative longitudinal movement between the core member and the elongated tubular support member.

2. A torqueable guidewire having a shaped distal section with adjustable flexibility comprising:

a) an elongated longitudinally movable core member having a shaped distal extremity, a proximal extremity, and a longitudinal axis extending through the core member wherein the core member is configured to transmit torque from the proximal extremity to the distal extremity;

b) a helical coil having a length axially adjustable by compression and expansion, a flexibility relative to the length, a proximal portion, and a distal portion secured to the distal extremity of the longitudinally movable core member, wherein the helical coil is disposed about the distal extremity of the core member and is slidable with respect thereto;

c) a shaped distal section including the distal extremity of the movable core member and the helical coil, adjustable from a flexible shaped condition where said distal section is in an orientation that is not coaxial with a portion of the core member proximal to the distal section to a straightened stiffer condition where said distal section is in an orientation that is coaxial with a portion of the core member proximal to the distal section;

d) an elongated tubular support member which is disposed about the longitudinally movable core member and proximal to the helical coil, which is slidable with respect to the core member and which has a distal end configured to support the proximal portion of the coil; and

e) tension means to apply tension to the core member and substantially uniformly adjust the compression and axial length of the helical coil by stacking the helical coil to thereby stiffen the shaped distal section of the guidewire and straighten the shaped distal section to an orientation coaxial with the core member longitudinal axis, be effecting relative longitudinal movement between the core member and the elongated tubular support member without causing deflection off the distal extremity away from the longitudinal axis of the core member.

3. The torqueable guidewire of claim 2 wherein at least a portion of the helical coil is expanded.

4. The guidewire of claim 2 wherein the helical coil forms an annular lumen about the longitudinally movable core member.

5. The guidewire of claim 4 wherein a center coil is slidably disposed around the distal end of the movable core member within the lumen of the helical coil and substantially along the length of the helical coil.

6. The guidewire of claim 2 wherein the elongated tubular support member includes a proximal section comprising a length of hypotubing having proximal and distal ends.

7. The guidewire of claim 6 wherein the tensioning means is secured to the proximal end of the hypotube to effect relative longitudinal movement between the core member and the elongated tubular support member.

8. The guidewire of claim 7 wherein the tensioning means to effect relative longitudinal movement has a distal portion and a proximal portion spaced a distance from each other with a rotating knob between the distal and proximal portions wherein rotating the knob changes the distance between the distal portion and the proximal portion of the tensioning means.

9. The guidewire of claim 6 wherein the elongated tubular support member has an intermediate coil secured to the distal end of the hypotube and an outer sleeve secured to an exterior portion of the intermediate coil.

10. The guidewire of claim 9, wherein the intermediate coil has a length of about 40 cm to about 44 cm.