Medical balloon with varied compliance
A medical lumen-expansion balloon may include a generally cylindrical central body between first and second body end portions, a low-profile unexpanded first state and a radially-expanded second state, wherein the first body end portion is constrained by fiber material such that it will not expand longitudinally and circumferentially beyond a predetermined size, and the central body is constrained by fiber material so as to be circumferentially substantially noncompliant, but is longitudinally compliant, such that it will elongate with increased volume but will not substantially radially expand.
1. A medical lumen-expansion balloon comprising:
a generally cylindrical central body defining a length between first and second body end portions that transition from the central body to ends of the balloon;
a low-profile unexpanded first state;
a radially-expanded second state wherein the central body defines an outer inflated diameter, wherein
the first body end portion and second body end portion taper from the central body to the respective ends of the balloon and are substantially non-compliant such that neither the first body end portion nor the second body end portion will expand longitudinally and circumferentially once the central body is inflated to the outer inflated diameter, and
the central body comprises a plurality of circumferentially-constraining fibers extending circumferentially around the central body and spaced apart from one another along the length such the central body is circumferentially substantially noncompliant, but is longitudinally compliant, the circumferentially-constraining fibers configured to allow the central body to elongate with increased volume but not substantially radially expand beyond the outer inflated diameter, and at least one smaller diameter circumferential constraint fiber surrounding the central body having a smaller diameter than adjacent circumferential-constraining fibers when the central body is inflated to the outer inflated diameter.
2. The balloon of claim 1 , further comprising a plurality of balloon-deployable stents disposed around the central body over the circumferential-constraining fibers, ends of adjacent stents spaced apart from one another that are deployable from the balloon for deployment in a lumen of a patient.
3. The balloon of claim 2 , where the at least one smaller diameter circumferential constraint fiber is disposed between one of the stents and an outer surface of the balloon, longitudinally central relative to the stent, such that the at least one smaller diameter circumferential constraint fiber restricts radial expansion of the central body under the stent to prevent longitudinal movement of the stent during deployment.
4. The balloon of claim 3 , where at least one smaller diameter circumferential constraint fiber is provided under each of the plurality of stents to prevent longitudinal movement of the stents during deployment.
5. The balloon of claim 1 , wherein the first body end portion and the second body end portion are reinforced with constraining fibers configured to prevent the first body end portion and the second body end portion from expanding longitudinally and circumferentially once the central body is inflated to the outer inflated diameter.
6. The balloon of claim 1 , wherein the one or more circumferentially-constraining fibers are wound around or attached to the central body.
7. The balloon of claim 1 , wherein the one or more circumferentially-constraining fibers define loops extending circumferentially around the central body and separated by gaps along the length.
8. The balloon of claim 7 , wherein one or more of the loops are configured to expand to a constraining diameter smaller than the outer inflated diameter such that the one or more loops create one or more smaller diameter regions when the central body is inflated to the second state.
9. The balloon of claim 1 , further comprising longitudinal fibers extending along the central body that remain loose when the central body is inflated to the outer inflated diameter such that the longitudinal fibers do not limit lengthening of the central body upon further inflation.
10. The balloon of claim 1 , wherein the central body comprises elastomeric material, and wherein the one or more circumferentially-constraining fibers are spaced apart to allow the elastomeric material to bulge between longitudinally adjacent fiber regions to provide a ribbed outer surface contour.
11. A medical lumen-expansion balloon comprising:
a generally cylindrical central body having a length between first and second body end portions that transition from the central body to ends of the balloon;
a low-profile unexpanded first state;
a radially-expanded second state wherein the central body defines an outer inflated diameter, wherein
the first body end portion tapers from the central body to a first of the ends of the balloon and is constrained by fiber material such that the first body portion will not expand longitudinally and circumferentially beyond a predetermined tapered size, and
the central body is constrained by a plurality of circumferentially-constraining fibers extending circumferentially around the central body and spaced apart from one another along the length so as to be circumferentially substantially noncompliant, but is longitudinally compliant, such that the central body will elongate with increased volume but will not substantially radially expand beyond the outer inflated diameter, and at least one smaller diameter circumferential constraint fiber surrounding the central body having a smaller diameter than adjacent circumferential-constraining fibers when the central body is inflated to the outer inflated diameter.
12. The balloon of claim 11 , where the central body portion includes a first circumferentially fiber-constrained length with a different maximal outer diameter than a second circumferentially fiber-constrained length.
13. The balloon of claim 11 , wherein the second body end portion tapers from the central body to a second of the ends of the balloon and is constrained by fiber material such that the second body portion will not expand longitudinally and circumferentially beyond a predetermined tapered size.
14. The balloon of claim 11 , wherein the one or more circumferentially-constraining fibers define loops extending circumferentially around the central body and separated by gaps along the length.
15. The balloon of claim 14 , wherein one or more of the loops are configured to expand to a constraining diameter smaller than the outer inflated diameter such that the one or more loops create one or more smaller diameter regions when the central body is inflated to the second state.
16. The balloon of claim 11 , wherein the central body comprises elastomeric material, and wherein the one or more circumferentially-constraining fibers are spaced apart to allow the elastomeric material to bulge between longitudinally adjacent fiber regions to provide a ribbed outer surface contour.
17. A balloon catheter, comprising:
a catheter shaft comprising a proximal end and a distal end;
a balloon comprising a generally cylindrical central body defining a length between first and second body end portions that taper to ends of the balloon attached to the distal end of the catheter shaft, the balloon expandable between a low-profile unexpanded first state and a radially-expanded second state wherein the central body defines an outer inflated diameter, wherein:
the first body end portion and second body end portion transition from the central body to the respective ends of the balloon and are substantially non-compliant such that the first body end portion and the second body end portion cannot expand longitudinally and circumferentially once the central body is inflated to the outer inflated diameter, and
the central body comprises a plurality of circumferentially-constraining fibers extending circumferentially around the central body and spaced apart from one another along the length of the central body such that the central body is circumferentially substantially noncompliant, but is longitudinally compliant, the circumferentially-constraining fibers configured to allow the central body to elongate with increased volume but not substantially radially expand beyond the outer inflated diameter; and
a plurality of balloon-deployable stents disposed around the central body over at least some of the circumferentially-constraining fibers, ends of adjacent stents spaced apart from one another that are deployable from the balloon in a lumen in a patient's body,
wherein the circumferentially-constraining fibers comprise first elements that constrain portions of the central body from expanding beyond the outer inflated diameter and second elements under respective stents that constraint expansion of the central body to a diameter smaller than the outer inflated diameter to prevent longitudinal movement of the stents during deployment.