Tissue-removing cathether with flexible distal tip
The present disclosure provides a tissue-removing catheter for removing tissue in a body lumen including an elongate drive member, tissue-removing element, and a distal tip. The elongate drive member is sized and shaped to be received in the body lumen. The elongate drive member rotates about an axis. The tissue-removing element is operatively coupled to a distal end portion of the elongate drive member and rotates by the elongate drive member to remove tissue in the body lumen. The distal tip extends distally outward from the tissue-removing element and is more flexible than tissue-removing element. The distal tip has a proximal end portion coupled to the tissue-removing element and a distal end portion spaced distally from the tissue-removing element. The distal tip defines a tip in communication with a liner passage that is configured to receive a guidewire therein.
1 . A tissue-removing catheter for removing tissue in a body lumen, the tissue-removing catheter comprising:
an elongate drive member having an axis and proximal and distal end portions spaced apart from one another along the axis, the elongate drive member being sized and shaped to be received in the body lumen and configured to be rotated about the axis;
a tissue-removing element operatively coupled to the distal end portion of the elongate drive member, the tissue-removing element being configured to be rotated by the elongate drive member to remove the tissue in the body lumen; and
a distal tip extending distally outward from the tissue-removing element and being configured to be more flexible than the tissue-removing element, wherein the distal tip has a proximal end portion coupled to the tissue-removing element and a distal end portion spaced distally from the tissue-removing element, the distal tip defining a tip opening extending through the proximal and distal end portions,
wherein the distal tip comprises a coil,
wherein the coil is configured to increase stiffness of the distal tip by compressing during rotation with the tissue-removing element.
2 . The tissue-removing catheter as set forth in claim 1 , wherein the distal tip further comprises a cap secured to the coil.
3 . The tissue-removing catheter as set forth in claim 2 , wherein the cap is secured directly to the coil at a distal end portion of the coil to inhibit unwinding of the coil.
4 . The tissue-removing catheter as set forth in claim 3 , wherein the cap covers a distalmost end of the coil.
5 . The tissue-removing catheter as set forth in claim 4 , wherein the cap comprises a polymeric material and is atraumatic.
6 . The tissue-removing catheter as set forth in claim 3 , wherein the cap adheres turns of the coil to one another.
7 . The tissue-removing catheter as set forth in claim 1 , wherein the coil has an abrasive exterior surface.
8 . The tissue-removing catheter as set forth in claim 1 , further comprising an inner liner disposed in the tip opening, wherein the inner liner is configured to receive a guidewire.
9 . The tissue-removing catheter as set forth in claim 8 , wherein the inner liner includes a low friction material to reduce friction imparted on the guidewire when the guidewire is received in the inner liner.
10 . The tissue-removing catheter as set forth in claim 8 , wherein the inner liner extends proximally into the drive shaft.
11 . The tissue-removing catheter as set forth in claim 8 , wherein a distalmost end of the inner liner does not extend distally beyond a distalmost end of the distal tip.
12 . The tissue-removing catheter as set forth in claim 1 , wherein the elongate drive member comprises a drive coil.
13 . A tissue-removing catheter for removing tissue in a body lumen, the tissue-removing catheter comprising:
an elongate drive member having an axis and proximal and distal end portions spaced apart from one another along the axis, the elongate drive member being sized and shaped to be received in the body lumen and configured to be rotated about the axis;
a tissue-removing element operatively coupled to the distal end portion of the elongate drive member, the tissue-removing element being configured to be rotated by the elongate drive member to remove the tissue in the body lumen; and
a distal tip extending distally outward from the tissue-removing element and being configured to be more flexible than the tissue-removing element, wherein the distal tip has a proximal end portion coupled to the tissue-removing element and a distal end portion spaced distally from the tissue-removing element, the distal tip defining a tip opening extending through the proximal and distal end portions,
wherein the distal tip comprises a polymeric material,
wherein the distal tip has a tapering portion defining a wall thickness that tapers toward the distal end portion of the distal tip to promote flexing of the distal tip.
14 . The tissue-removing catheter as set forth in claim 13 , further comprising an inner liner disposed in the tip opening of the distal tip, wherein the inner liner is configured to receive a guidewire.
15 . The tissue-removing catheter as set forth in claim 14 , wherein the inner liner includes a low friction material to reduce friction imparted on the guidewire when the guidewire is received in the inner liner.
16 . The tissue-removing catheter as set forth in claim 14 , wherein the inner liner extends proximally into the drive shaft.
17 . The tissue-removing catheter as set forth in claim 14 , wherein a distalmost end of the inner liner does not extend distally beyond a distalmost end of the distal tip.