Composite dressings for improved granulation and reduced maceration with negative-pressure treatment

1. A dressing for treating a tissue site with negative pressure, the dressing comprising:

a manifold comprising a first surface and a second surface opposite the first surface;

a first layer adjacent to the first surface and a second layer adjacent to the second surface, the first layer and the second layer each comprising a polymer film;

a plurality of fluid restrictions in the polymer film of both the first layer and the second layer; and

a sealing layer adjacent to at least one of the first layer and the second layer, the sealing layer having a plurality of apertures fluidly coupled to the fluid restrictions, wherein one or more of the plurality of apertures is sized to expose both the fluid restrictions and a portion of the polymer film around the fluid restrictions to the tissue site through the sealing layer, and wherein a dimension of one or more of the fluid restrictions in the polymer film exceeds a dimension of one or more of the plurality of apertures.

2. The dressing of claim 1 , wherein the polymer film is hydrophobic.

3. The dressing of claim 1 , wherein the polymer film has a contact angle with water greater than 90 degrees.

4. The dressing of claim 1 , wherein the polymer film is a polyethylene film.

5. The dressing of claim 1 , wherein the polymer film is selected from a group consisting of polythene, polyurethane, acrylics, polyolefines, polyacetates, polyamides, polyesters, polyether block amide, thermoplastic vulcanizates, polyethers, and polyvinyl alcohol.

6. The dressing of claim 1 , wherein the polymer film is a polyethylene film having an area density of less than 30 grams per square meter.

7. The dressing of claim 1 , wherein the fluid restrictions comprise a plurality of slots configured to permit fluid flow and inhibit exposure of the manifold to the tissue site.

8. The dressing of claim 1 , wherein the fluid restrictions comprise a plurality of slots, each of the slots having a length less than 4 millimeters.

9. The dressing of claim 1 , wherein the fluid restrictions comprise a plurality of slots, each of the slots having a width less than 2 millimeters.

10. The dressing of claim 1 , wherein the fluid restrictions comprise a plurality of slots, each of the slots having a length less than 4 millimeters and a width less than 2 millimeters.

11. The dressing of claim 1 , wherein the fluid restrictions comprise or consist essentially of elastomeric valves in the polymer film that are normally closed.

12. The dressing of claim 11 , wherein the elastomeric valves are fenestrations.

13. The dressing of claim 11 , wherein the elastomeric valves are slits.

14. The dressing of claim 1 , wherein the fluid restrictions comprise a plurality of slits in the polymer film, each of the slits having a length less than 4 millimeters.

15. The dressing of claim 14 , wherein the length is less than 3 millimeters.

16. The dressing of claim 14 , wherein the length is at least 2 millimeters.

17. The dressing of claim 1 , wherein the first layer and the second layer form a sleeve around the manifold.

18. The dressing of claim 1 , wherein the fluid restrictions are coextensive with the polymer film and the manifold.

19. The dressing of claim 1 , wherein the sealing layer is adjacent to both the first layer and the second layer.

20. The dressing of claim 1 , wherein the first layer and the second layer are laminated to the manifold.

21. The dressing of claim 1 , wherein at least one edge of the manifold is exposed through the polymer film.

22. The dressing of claim 1 , wherein one of the first layer or the second layer is configured to be interposed between the manifold and the tissue site.

23. The dressing of claim 1 , wherein the first layer and the second layer comprise an exposed surface that is smooth.

24. The dressing of claim 1 , wherein the manifold comprises a foam.

25. The dressing of claim 24 , wherein the foam is reticulated and has a free volume of at least 90%.

26. The dressing of claim 24 , wherein the foam is porous and has an average pore size in a range of 400-600 microns.

27. The dressing of claim 1 , wherein the manifold has a thickness less than 7 millimeters.

28. The dressing of claim 1 , wherein the manifold has a thickness in a range of 2 millimeters to 7 millimeters.

29. The dressing of claim 1 , wherein the manifold is hydrophobic.

30. The dressing of claim 1 , wherein the fluid restrictions are distributed across the polymer film in a uniform pattern.

31. The dressing of claim 30 , wherein the uniform pattern comprises a grid of parallel rows and columns.

32. The dressing of claim 1 , wherein:

the fluid restrictions are distributed across the polymer film in rows and columns that are parallel;

the rows are spaced about 3 millimeters on center; and

the fluid restrictions in each of the rows are spaced about 3 millimeters on center.

33. The dressing of claim 32 , wherein the fluid restrictions in adjacent rows are offset.

34. The dressing of claim 1 , further comprising:

a drape configured to be disposed over the manifold; and

a fluid port configured to be coupled to the drape and fluidly coupled to the manifold through the drape and the polymer film of at least one of the first layer and the second layer.

35. The dressing of claim 34 , wherein the drape is coupled to a periphery of the sealing layer to enclose the first layer, the second layer, and the manifold.

36. The dressing of claim 34 , wherein the drape and the sealing layer enclose the manifold and the polymer film, and the sealing layer is adapted to contact the tissue site.

37. The dressing of claim 34 , wherein the drape comprises a polymer film.

38. The dressing of claim 34 , wherein the drape comprises a margin that extends beyond the manifold and the polymer film, and an adhesive layer is disposed in the margin.

39. The dressing of claim 1 , the sealing layer comprising a hydrophobic gel having the plurality of apertures aligned with the fluid restrictions.

40. The dressing of claim 1 , the sealing layer comprising a hydrophobic gel having the plurality of apertures in registration with at least some of the plurality of fluid restrictions.

41. The dressing of claim 1 , the sealing layer comprising a hydrophobic gel having the plurality of apertures coextensive with the sealing layer and substantially all the plurality of apertures are in registration with the fluid restrictions.

42. The dressing of claim 1 , wherein the sealing layer comprises a silicone gel.

43. The dressing of claim 1 , wherein the sealing layer comprises a bonded silicone.

44. The dressing of claim 1 , the sealing layer having the plurality of apertures adjacent to the fluid restrictions and an area density less than 300 grams per square meter.

45. The dressing of claim 1 , wherein the sealing layer has a hardness of between about 5 Shore 00 and about 80 Shore OO.

46. The dressing of claim 1 , wherein the sealing layer is configured to be interposed between the manifold and the tissue site.

47. The dressing of claim 1 , wherein the dimension of the one or more of the fluid restrictions comprises a length that exceeds the dimension of the one or more of the plurality of apertures such that the length overlaps an edge of the one or more of the plurality of apertures.

48. The dressing of claim 1 , wherein the sealing layer has a smooth lower surface.

49. The dressing of claim 1 , wherein the sealing layer is configured to provide a fluid-tight seal with the tissue site.

50. The dressing of claim 1 , wherein the polymer film is bonded to the manifold.

51. The dressing of claim 1 , wherein the dressing comprises a smooth surface configured to contact the tissue site.

52. A system for treating a tissue site, the system comprising:

the dressing of claim 1 ; and

a negative-pressure source fluidly coupled to the dressing or apparatus.

53. The system of claim 52 , further comprising a fluid container fluidly coupled between the dressing and the negative-pressure source.