Catheter having an improved balloon-to-catheter bond
View Patent ↗A tie layer insert is disclosed to aid in bond formation between an expandable balloon and a distal portion of a catheter shaft. The tie layer insert can be a single layer applied directly to the structural surfaces, or alternatively, the tie layer may be incorporated into a preformed polymeric insert. In the latter embodiment, the polymeric insert may include several layers of polymeric material. During the manufacturing process, the preformed polymeric insert is positioned between the distal portion of the expandable balloon and the catheter shaft. The entire distal region is then processed to form a sealably bonded expandable balloon to the distal end of the catheter shaft.
1. A balloon catheter, comprising:
an outer tubular member having a distal end region;
an inner tubular member disposed within the outer tubular member, the inner tubular member having a distal end region That extends distally from the distal end region of the outer tubular member;
a balloon having a proximal portion and a distal portion, the proximal portion being attached to the distal end region of the outer tubular member and the distal portion being attached to the distal end region of the inner tubular member;
wherein the distal portion of the balloon defines a distal waist having a distal waist length; and
a tie layer defined by a heat shrink tubular member that is disposed between the distal waist of the balloon and the distal end region of the inner tubular member, the heat shrink tubular member being heat shrunk to the inner tubular member and being thermally bonded to the distal waist of the balloon, the tie layer having a length that is substantially the same as thd distal waist length.
2. The balloon catheter of claim 1 , wherein the tie layer includes low density polyethylene.
3. The balloon catheter of claim 1 , wherein the tie layer is heat-shrunk onto the inner tubular member.
4. The balloon catheter of claim 1 , wherein the tie layer is multi-layered.
5. The balloon catheter of claim 1 , wherein the inner tubular member includes polyethylene and wherein the tie layer has a relatively high bonding affinity for polyethylene.
6. The balloon catheter of claim 1 , wherein the inner tubular member includes polytetrafluoroethylene and wherein the tie layer has a relatively high bonding affinity for polytetrafluoroethylene.
7. A balloon catheter, comprising:
a first tubular member having a distal end region;
a second tubular member disposed within the first tubular member, the second tubular member having a distal end region that extends distally from the distal end region of the first tubular member;
a balloon having a proximal portion and a distal portion, the proximal portion being attached to the distal end region of the first tubular member and the distal portion being attached to the distal end region of the second tubular member;
wherein the distal portion of the balloon defines a distal waist having a distal waist length; and
a tie layer insert disposed between and thermally bonded to both the distal waist of the balloon and the distal end region of the second tubular member, the tie layer insert having a length that is substantially the same as the distal waist length.
8. The balloon catheter of claim 7 , wherein the tie layer insert includes low density polyethylene.
9. The balloon catheter of claim 7 , wherein the tie layer insert is heat-shrunk onto the second tubular member.
10. The balloon catheter of claim 7 , wherein the tie layer insert includes a plurality of layers.
11. The balloon catheter of claim 7 , wherein the second tubular member includes polyethylene and wherein the tie layer has a relatively high bonding affinity for polyethylene.
12. The balloon catheter of claim 7 , wherein the second tubular member includes polytetrafluoroethylene and wherein the tie layer has a relatively high bonding affinity for polytetrafluoroethylene.
13. A balloon catheter, comprising:
an outer tubular member having a distal end region;
an inner tubular member disposed within the outer tubular member, the inner tubular member having a distal end region that extends distally from the distal end region of the outer tubular member;
a balloon having a proximal portion and a distal portion having a length, the proximal portion being attached to the distal end region of to outer tubular member and the distal portion being attached to the distal end region of the inner tubular member; and
a multi-layer insert disposed between the distal portion of the balloon and the distal end region of the inner tubular member, the multi-layer insert having a length that is substantially the same as the length of the distal portion of the balloon.
14. A method for bonding a balloon to a catheter shaft, the method comprising the steps of:
providing a catheter shaft, the catheter shaft including an outer tubular member with a distal end region and an inner tubular member disposed within the outer tubular member, the inner tubular member having a distal end region that extends distally from the distal end region of the outer tubular member;
providing a tie layer having a length;
thermally bonding the tie layer onto a portion of the distal end region of the inner tubular member;
providing a balloon having a proximal waist, a distal waist, and an expandable region therebetween, the distal waist having a length that is substantially the same as the length of the tie layer; and
affixing the distal waist of the balloon to tie layer.
15. The method of claim 14 , wherein the step of thermally bonding the tie layer onto a portion of the distal end region of the inner tubular member includes heat shrinking the tie layer onto a portion of the distal end region of the inner tubular member.
16. The method of claim 14 , wherein the step of affixing the distal waist of the balloon to tie layer includes thermally bonding the distal waist of the balloon to the tie layer.