Devices and methods for treatment of the Eustachian tube and sinus cavity
A polymeric stent can be implanted for treatment of the Eustachian tube. The stent can be designed to have length-dependent radial strength to allow it to stay within the Eustachian tube and to allow normal closing and opening of the Eustachian tube. A balloon can be used to implant the stent, and the balloon can be coated with a therapeutic agent. A coated balloon can also be used to transfer therapeutic agents to the sinus cavity during a balloon sinus dilation procedure.
1. A polymeric stent for treating the Eustachian tube, the stent comprising:
a tubular scaffold configured for implantation in the Eustachian tube, the tubular scaffold having a polymer substrate, the tubular scaffold including a proximal segment and a distal segment, the proximal segment including radially deformable rings, the radially deformable rings of the distal segment having a greater radial strength than the radially deformable rings of the proximal segment, wherein the tubular scaffold has an uncrimped configuration and a crimped configuration, wherein the scaffold is cut from a frustoconical tube so that in the uncrimped state a diameter of the rings decreases linearly from a distal end to a proximal end of the scaffold, wherein the proximal segment begins at an end ring at the proximal end of the tubular scaffold and the distal segment begins at an end ring at the distal end of the tubular scaffold, wherein the proximal segment abuts the distal segment.
2. The polymeric stent of claim 1 , wherein discontinuities are present in the radially deformable rings of the proximal segment, each of the discontinuities are defined as a cut through a full width and a full thickness of the radially deformable ring in which the discontinuity is present, and discontinuities are absent from the radially deformable rings of the distal segment.
3. The polymeric stent of claim 1 , wherein one or more of the radially deformable rings of the distal segment have polymer molecules that have a preferential orientation that is less axial than that of the radially deformable rings of the proximal segment.
4. The polymeric stent of claim 1 , wherein one or more of the radially deformable rings of the distal segment have full widths that are greater than that of one or more of the radially deformable rings of the proximal segment.
5. The polymeric stent of claim 1 , wherein one or more of the radially deformable rings of the distal segment have full thicknesses that are greater than that of one or more of the radially deformable rings of the proximal segment.
6. The polymeric stent of claim 1 , wherein the polymer substrate of one or more of the radially deformable rings of the distal segment has a molecular weight greater than that of the polymer substrate of one or more of the radially deformable rings of the proximal segment.
7. The polymeric stent of claim 1 , wherein the polymer substrate includes a base component and a dopant having a lower elastic modulus than that of the base component, the base component is present at a higher percentage than the dopant in the polymer substrate of the radially deformable rings of the distal segment, and the dopant is present at a higher percentage than the base component in the polymer substrate of the radially deformable rings of the proximal segment.
8. The polymeric stent of claim 1 , wherein the polymer substrate of one or more radially deformable rings of the distal segment has at least one parameter greater than that of the polymer substrate of one or more radially deformable rings of the proximal segment, the at least one parameter being any one or more of: melt temperature, glass transition temperature, and percent crystallinity.
9. The polymeric stent of claim 1 , wherein one or more of the radially deformable rings of the distal segment have outer diameters that are greater than that of one or more of the radially deformable rings of the proximal segment.
10. The polymeric stent of claim 1 , wherein the tubular scaffold includes a plurality of stent marks, the stent marks are spaced equally apart from each other, and each of the stent marks has a characteristic that differentiates the stent mark from a portion of the tubular scaffold that is adjacent to the stent mark, and the characteristic is an opacity, a color, a shade, a shape, an alphanumeric character, or a combination thereof.
11. The polymeric stent of claim 1 , wherein a wall thickness of the frustoconical tube decreases between the distal end to the proximal end so that a thickness of the rings decreases from the distal end to the proximal end.