Balloon catheter with non-deployable stent
An angioplasty balloon including a non-deployable stent to prevent or reduce the potential for slippage of the inflated balloon with respect to the vessel wall being treated. The balloon includes a non-deployable stent that is adapted to be secured to the balloon or angioplasty balloon catheter. The stent has a proximal end, a distal end, and at least three radially-spaced struts, each, each strut connecting the proximal end to the distal end and having one or more bends that allow expansion of the strut to accommodate the inflation of the balloon. The stem is made or a material so that the stent collapses upon deflation of the balloon.
1. A system for performing angioplasty, said system comprising:
a catheter shaft having a distal end and an inflatable balloon disposed adjacent the distal end, wherein the inflatable balloon comprises a working length; and
an expandable constraining structure disposed over the inflatable balloon, wherein the expandable constraining structure comprises a plurality of axial struts and at least one ring, wherein each of the axials struts comprise a central portion, wherein the ring is disposed over the working length of the inflatable balloon and intersects the central portions of the axial struts, said expandable constraining structure having a non-expanded configuration and an expanded configuration, wherein the non-expanded configuration comprises the expandable constraining structure lying closely over the inflatable balloon prior to inflation of the inflatable balloon, wherein the expanded configuration comprises the expandable constraining structure being smaller than an unconstrained size of the expandable balloon upon inflation of the inflatable balloon so that the expandable constraining structure restrains the inflatable balloon along a plurality of crossing channel lines, wherein the axial struts are joined to the catheter on a distal side of the balloon and a proximal side of the balloon wherein both ends of said constraining structure are fixedly attached to the catheter shaft.
2. A system as in claim 1 , wherein the channel lines are oriented axially, circumferentially, or both axially and circumferentially.
3. A system as in claim 2 , wherein the expandable constraining structure comprises a multiplicity of axially spaced-apart radially expandable rings attached to the axial struts, wherein the axial struts are circumferentially spaced-apart and cross the radially expandable rings.
4. A system as in claim 3 , wherein the rings are joined to the struts at intersecting angles of 90°.
5. A system as in claim 3 , wherein the radially expandable rings are composed of an elastic material which can elongate to allow the rings to expand when the inflatable balloon is inflated.
6. A system as in claim 5 , wherein the radially expandable rings are formed with deformable features which allow their radial expansion when the balloon is inflated.
7. A system as in claim 6 , wherein the deformable features comprise one or more of zig-zags, S-curves, and coils.
8. A system as in claim 1 , wherein the axial struts are each elastic in tension so that they will elongate as the inflatable balloon inflates.
9. A method for treating a lesion in a blood vessel, said method comprising:
inflating a balloon and expanding an expandable constraining structure, within the blood vessel, wherein the expandable constraining structure comprises a plurality of circumferentially spaced-apart axial struts and a plurality of axially spaced-apart radially expandable rings wherein the axial struts cross the rings, thereby creating openings in the expandable constraining structure, the plurality of axially spaced-apart radially expandable rings comprising a distal ring, a proximal ring and an intermediate ring between the distal ring and proximal ring, wherein the axial struts are joined to the catheter on a distal side of the balloon and a proximal side of the balloon; wherein both ends of said constraining structure are fixedly attached to the catheter shaft; and
constraining the balloon inflation along a plurality of crossing channel lines formed by said axial struts and said rings, whereupon inflation of the balloon, the expandable constraining structure has a configuration smaller than an unconstrained size of the balloon.
10. A method as in claim 9 , wherein the balloon is composed of a non-distensible or semi-compliant material and is inflated to a pressure in the range from 10 atm. to 25 atm.
11. A method as in claim 9 , wherein the balloon is constrained along crossing axial and circumferential channel lines to form quadrangular isolated protruding regions.
12. A method as in claim 9 , wherein a plurality of protruding regions have similar sizes and are uniformly distributed over the balloon surface.
13. A system for performing angioplasty, said system comprising:
a catheter shaft having an inflatable balloon adjacent its distal end; and
an expandable constraining structure disposed over the inflatable balloon, wherein both ends of said constraining structure are directly affixed attached to the catheter shaft, the expandable constraining structure comprising a plurality of circumferentially spaced-apart axial struts and a plurality of axially spaced-apart radially expandable rings coupled to the axial struts, the plurality of axially spaced-apart radially expandable rings comprising a distal ring, a proximal ring and an intermediate ring between the distal ring and proximal ring, wherein a portion of the axial struts is un-affixed to the inflatable balloon, wherein the axial struts cross the radially expandable rings, wherein the expandable constraining structure comprises a non-expanded configuration and an expanded configuration, wherein the expandable constraining structure is in the non-expanded configuration when the inflatable balloon is in a deflated state and the expandable constraining structure is in the expanded configuration when the inflatable balloon is in an inflated state, whereupon the expandable constraining structure being in the non-expanded configuration, the expandable constraining structure lies closely over the inflatable balloon, and whereupon the expandable constraining structure being in the expanded configuration, the expandable constraining structure restrains inflation of the inflatable balloon along the axial struts.
14. The system of claim 13 , whereupon the expandable constraining structure being in the non-expanded configuration, the expandable constraining structure comprises a different configuration than the inflatable balloon in the deflated state.
15. The system of claim 14 , whereupon the expandable constraining structure being in the expanded configuration, the expandable constraining structure comprises a different configuration than the inflatable balloon in the inflated state.
16. The system of claim 13 , whereupon the expandable constraining structure being in the expanded configuration, the expandable constraining structure comprises a different configuration than the inflatable balloon in the inflated state.
17. A system as in claim 3 , wherein the multiplicity of axially spaced-apart radially expandable rings comprises a distal ring, a proximal ring and an intermediate ring between the distal ring and proximal ring and the intermediate ring is the at least one ring.
18. A system as in claim 17 , wherein the distal ring, the proximal ring and the intermediate ring are disposed over a working length of the inflatable balloon.