Spacing device for releasing active substances in the paranasal sinus
A spacing device for use in fenestrations of the paranasal sinus, the device including a sheath which forms a hollow body defining at least two apertures. The sheath includes at least one layer loaded with an active substance. The ratio q of the external diameter r a of the hollow body to the internal diameter r i of the hollow body is about 1.2 to 3.0.
1. A substance delivering spacer device for implantation in an opening of a paranasal sinus, said device comprising:
a tubular body having a wall, a hollow passage extending therethrough and being open at either end and perforations formed in the wall through which bodily secretions may flow into the hollow passage, the wall of said tubular body comprising:
an inner layer comprising a polymer that is devoid of therapeutic substance;
an outer layer comprising a polymer that is devoid of therapeutic substance; and
a therapeutic substance containing layer located between the inner and outer layers, said therapeutic substance containing layer being substantially solid and comprising a polymer combined with a therapeutic substance such that the therapeutic substance will elute therefrom when the device is implanted;
wherein said outer layer is constructed to allow a therapeutically effective amount of the therapeutic substance to elute through the outer layer and from the device while implanted,
wherein said inner layer is substantially impervious to the therapeutic substance,
wherein said therapeutic substance comprises at least one steroid;
said tubular body being flexible and sufficiently elastic to frictionally engage and remain in the opening following its insertion into the opening; and the device having an outer diameter r a and an inner diameter r i , wherein the ratio Q of the outer diameter r a to the inner diameter r i is greater than or equal to 1.2 but less than or equal to 3.0.
2. A device according to claim 1 wherein the substance elutes from the device over a period of from 2-12 weeks following implantation of the device.
3. A device according to claim 1 wherein at least a portion of the device is biodegradable.
4. A device according to claim 3 wherein erosion of a biodegradable portion of the device results in release of the substance from the device.
5. A device according to claim 1 wherein the device has a substantially constant outer diameter over its entire length.
6. A device according to claim 1 wherein the device has regions of differing outer diameter.
7. A device according to claim 6 wherein the ends of the device are larger in outer diameter than the remainder of the device.
8. A device according to claim 1 wherein the polymeric material comprises poly(ethylene-vinyl acetate) copolymer.
9. A device according to claim 8 wherein the polymeric material also contains one or more additives to affect the rate at which the substance is released from the substance containing layer.
10. A device according to claim 8 wherein the therapeutic substance accounts for up to 30% of the total weight of the substance containing layer.
11. A device according to claim 1 wherein at least the outer surface of the device is formed from a material selected from biodegradable polymers, non-biodegradable polymers, shape memory materials and formable materials.
12. A device according to claim 1 wherein the inner layer, the substance containing layer and the outer layer each comprises a substantially solid polymer.
13. A device according to claim 12 wherein the substance containing layer and the outer layer are formed substantially of the same polymer.
14. A device according to claim 12 wherein the substance containing layer and the outer layer are formed of different polymers.
15. A device according to either of claim 13 or 14 wherein the polymer or polymers is/are selected from the group consisting of: poly(alpha-hydroxy esters), polyacrylates, ethylene vinyl acetate copolymer and silicone.
16. A device according to claim 1 wherein the therapeutic substance further comprises at least one additional agent selected from the group consisting of: bacteriocides, bacteriostats and mixtures thereof.
17. A device according to claim 1 further comprising a coating disposed on the device to improve biocompatibility.
18. A device according to claim 1 wherein said at least one steroid comprises a glucocorticoid.
19. A device according to claim 1 wherein said at least one steroid comprises a steroid selected from the group consisting of: cortisol, corisone, prednisone, prednisolone, 6-methylprednisolone, dexamethasone, fludrocortisone, desoxycorticoacetate.
20. A method for treating a disorder that affects a paranasal sinus, middle ear or trachea, said method comprising the steps of
A) providing a substance delivering spacer device for implantation in an opening of a paranasal sinus, said device comprising:
a tubular body having a side wall, a hollow passage extending therethrough and being open at either end and perforations formed in the wall through which bodily secretions may flow into the hollow passage, the wall of said tubular body comprising:
an inner layer comprising a polymer that is devoid of therapeutic substance;
an outer layer comprising a polymer that is devoid of therapeutic substance; and
a therapeutic substance containing layer located between the inner and outer layers, said therapeutic substance containing layer being solid and comprising a polymer combined with a therapeutic substance such that the therapeutic substance will elute therefrom when the device is implanted;
wherein said outer layer is constructed to allow a therapeutically effective amount of the therapeutic substance to elute through the outer layer and from the device while implanted,
wherein said inner layer is substantially impervious to the therapeutic substance,
wherein said therapeutic substance comprises at least one steroid;
said tubular body being flexible and sufficiently elastic to frictionally engage and remain in the opening following its insertion into the opening; and
the device having an outer diameter r a and an inner diameter r i , wherein the ratio Q of the outer diameter r a to the inner diameter r i is greater than or equal to 1.2 but less than or equal to 3.0; and
B) implanting the device in an opening of a paranasal sinus such that a therapeutic amount of the therapeutic substance is delivered to the opening of a paranasal sinus in which the device is implanted.
21. A method according to claim 20 wherein Step B comprises implanting the device in an opening of a frontal sinus.
22. A method according to claim 20 wherein Step B comprises implanting the device in an opening of a paranasal sinus that has been dilated.
23. A method according to claim 20 wherein Step B comprises implanting the device in an opening of a paranasal sinus that has been surgically altered.
24. A method according to claim 20 wherein the device is implanted in a surgically created fenestration.
25. A method according to claim 20 wherein the device is capable of being radially expanded and wherein Step B comprises radially expanding the device at an intended site of implantation.
26. A method according to claim 25 wherein the device is radially expanded by inflating a balloon positioned within the device.
27. A method according to claim 20 further comprising the step of:
C) removing the device.
28. A method according to claim 27 wherein the device is removed approximately 2 to 12 weeks after implantation.
29. A system comprising a substance delivering spacer device according to claim 1 in combination with a balloon that is positionable and inflatable within the hollow passage of the substance delivering spacer device to widen at least a portion of the substance delivering spacer device.