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

Abstract

A dressing for treating a tissue site with negative pressure may include a first layer having a first side, a second side, and fenestrations having a raised edge extending from the first side. The raised edge is configured to expand in response to a pressure gradient across the first layer. The dressing also includes a second layer adjacent to the first side. The second layer includes a manifold. The dressing also includes a cover coupled to the second layer opposite the first layer. The cover includes a polymer drape.

1 .- 29 . (canceled) 
     
     
         30 . A dressing for treating a tissue site with negative pressure, the dressing comprising:
 a first layer comprising a film having perforations and fenestrations through the film that are configured to expand in response to a pressure gradient across the film;   a second layer adjacent to the first layer, the second layer comprising a manifold; and   a cover adjacent to the second layer opposite the first layer.   
     
     
         31 . The dressing of  claim 30 , wherein:
 the film has a central zone and a peripheral zone;   the manifold is at least partially disposed adjacent to the central zone;   the perforations are disposed in the central zone; and   the fenestrations are disposed in the peripheral zone.   
     
     
         32 . The dressing of  claim 30 , wherein:
 the film has a central zone;   at least some of the perforations and the fenestrations are disposed in the central zone; and   a ratio of the perforations to the fenestrations in the central zone is greater than 1:1.   
     
     
         33 . (canceled) 
     
     
         34 . The dressing of  claim 30 , wherein:
 the film has a peripheral zone;   at least some of the perforations and the fenestrations are disposed in the peripheral zone; and   a ratio of the perforations to the fenestrations in the peripheral zone is less than 1:1.   
     
     
         35 . (canceled) 
     
     
         36 . The dressing of  claim 30 , wherein:
 the film has a first zone and a second zone;   a ratio of the perforations to the fenestrations in the first zone is greater than 1:1; and   a ratio of the perforations to the fenestrations in the second zone is less than 1:1.   
     
     
         37 . (canceled) 
     
     
         38 . The dressing of  claim 30 , wherein:
 the film has a manifolding area comprising a central zone and a peripheral zone;   the central zone is coextensive with about 50% of the manifolding area;   the peripheral zone is coextensive with about 50% of the manifolding area;   a ratio of the perforations to the fenestrations in the central zone is greater than 1:1; and   a ratio of the perforations to the fenestrations in the peripheral zone is less than 1:1.   
     
     
         39 . (canceled) 
     
     
         40 . The dressing of  claim 30 , wherein:
 the film has a manifolding area comprising a central zone and a peripheral zone;   the central zone is coextensive with about 50% of the manifolding area;   the peripheral zone is coextensive with about 50% of the manifolding area;   the manifold is at least partially disposed adjacent to the central zone;   a ratio of the perforations to the fenestrations in the central zone is about 8:2; and   a ratio of the perforations to the fenestrations in the peripheral zone is about 2:8.   
     
     
         41 . A dressing for treating a tissue site with negative pressure, the dressing comprising:
 a fluid control layer comprising fluid restrictions that are elastomeric and configured to be responsive to a pressure gradient across the fluid control layer;   a manifold layer adjacent to the fluid control layer;   a cover adjacent to the manifold layer opposite the fluid control layer; and   a sealing layer adjacent to the fluid control layer opposite the manifold layer, the sealing layer comprising apertures aligned with the fluid restrictions;   wherein the fluid control layer and the sealing layer each have a contact angle with water of at least 70 degrees;   wherein the fluid control layer and the sealing layer are each less than 100 microns thick; and   wherein the fluid control layer and the sealing layer have a hardness in a range of 20 Shore A to 90 Shore A.   
     
     
         42 . The dressing of  claim 41 , wherein the fluid control layer comprises a polymer film of polylactic acid, carboxymethyl cellulose, or polycaprolactone. 
     
     
         43 . The dressing of  claim 41 , wherein the fluid control layer comprises a film of xanthan gum mixed with at least one of collagen, oxidized regenerated cellulose, and alginate. 
     
     
         44 . The dressing of  claim 41 , wherein the fluid control layer comprises a film of xanthan gum and citric acid mixed with at least one of collagen, oxidized regenerated cellulose, and alginate. 
     
     
         45 . The dressing of  claim 41 , wherein the fluid control layer comprises a film co-polymerized with dialkylcarbamoylchloride. 
     
     
         46 . The dressing of  claim 41 , wherein the fluid control layer comprises a film coated with petrolatum gel. 
     
     
         47 . (canceled) 
     
     
         48 . The dressing of  claim 41 , wherein the fluid control layer comprises a film coated with petrolatum gel having a viscosity of at least 10000 millipascal seconds and anti-microbial compounds. 
     
     
         49 . (canceled) 
     
     
         50 . The dressing of  claim 41 , wherein the fluid control layer comprises a film coated with petrolatum gel having a viscosity of at least 10000 millipascal seconds and anti-microbial compounds, the film formed from at least one of polyethylene, polyurethane, and ethyl methyl acrylate. 
     
     
         51 . (canceled) 
     
     
         52 . (canceled) 
     
     
         53 . The dressing of  claim 41 , wherein the manifold layer comprises:
 foam having open cells formed from felted polyurethane; and   perforations through the foam.   
     
     
         54 . (canceled) 
     
     
         55 . The dressing of  claim 41 , wherein the manifold layer comprises at least two layers of woven textile with inter-woven polymer strands. 
     
     
         56 . (canceled) 
     
     
         57 . (canceled) 
     
     
         58 . The dressing of  claim 41 , wherein the manifold layer comprises:
 a first wicking layer;   a second wicking layer; and   an absorbent disposed between the first wicking layer and the second wicking layer.   
     
     
         59 . The dressing of  claim 41 , wherein the manifold layer comprises at least two sheets formed of sodium carboxymethylcellulose. 
     
     
         60 . (canceled) 
     
     
         61 . (canceled) 
     
     
         62 . The dressing of  claim 41 , wherein the manifold layer comprises polymer beads and at least some of the fluid restrictions are fluidly coupled with spaces between the polymer beads. 
     
     
         63 . The dressing of  claim 41 , wherein the manifold layer comprises polymer projections and at least some of the fluid restrictions are fluidly coupled with spaces between the polymer projections. 
     
     
         64 . The dressing of  claim 41 , wherein the manifold layer comprises an embossed polymer film. 
     
     
         65 . (canceled) 
     
     
         66 . (canceled) 
     
     
         67 . The dressing of  claim 41 , wherein the manifold layer comprises foam having closed cells and perforations through the foam. 
     
     
         68 . The dressing of  claim 41 , wherein the manifold layer comprises:
 a film substrate;   a plurality of fibers extending from the film substrate; and   perforations or fenestrations in the film substrate.   
     
     
         69 . (canceled)