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

Abstract

A dressing may comprise a manifold having a first planar surface and a second planar surface opposite the first planar surface, and a first layer adjacent to the first planar surface and a second layer adjacent to the second planar surface. The first layer and the second layer may be laminated to the first planar surface and the second planar surface, respectively. Pressure-responsive fluid restrictions through at least one of the first layer and the second layer may be adjacent to the manifold. The first layer and the second layer may also form a sleeve or an envelope around the manifold in some embodiments. At least one of the first layer and the second layer may be configured to be disposed between the manifold and a tissue site in use. In some examples, the dressing may have a smooth or matte surface configured to contact a tissue site.

1 - 69 . (canceled) 
     
     
         70 . A dressing for treating a tissue site with negative pressure, the dressing comprising:
 a manifold formed from a hydrophobic material;   a film substantially enclosing the manifold, the film formed from a hydrophobic material; and   a plurality of fluid passages through the film, the plurality of fluid passages configured to expand in response to a pressure gradient across the film.   
     
     
         71 . The dressing of  claim 70 , further comprising:
 a polymer drape coupled to the film;   a hydrophobic gel coupled to the film opposite the polymer drape, the hydrophobic gel having an area density less than 300 grams per square meter; and   a plurality of apertures through the hydrophobic gel fluidly coupled to at least some of the plurality of fluid passages through the film.   
     
     
         72 . The dressing of  claim 70 , wherein the film forms a sleeve around the manifold. 
     
     
         73 . The dressing of  claim 70 , wherein the film forms an envelope around the manifold. 
     
     
         74 . A dressing for treating a tissue site with negative pressure, the dressing comprising:
 a first layer comprising a first film having a flat surface texture;   a second layer adjacent to the first layer, the second layer comprising a manifold;   a third layer adjacent to the second layer opposite the first layer, the third layer comprising a second film having a flat surface texture; and   a plurality of fluid restrictions through the first film, the plurality of fluid restrictions configured to be responsive to a pressure gradient across the fluid restrictions.   
     
     
         75 . The dressing of  claim 74 , wherein the plurality of fluid restrictions are through the first film and the second film. 
     
     
         76 . The dressing of  claim 74 , further comprising:
 a fourth layer coupled to the third layer opposite the first layer, the third layer comprising a polymer drape;   a fifth layer coupled to the first layer opposite the second layer, the fifth layer comprising a gel having an area density less than 300 grams per square meter and a hardness between about 5 Shore OO and about 80 Shore OO; and   a plurality of apertures through the fifth layer aligned with at least some of the plurality of fluid restrictions.   
     
     
         77 . An apparatus for treating a tissue site with negative pressure, the apparatus comprising:
 a tissue interface comprising a manifold and a film covering at least two sides of the manifold, the manifold and the film formed from a hydrophobic material;   a plurality of elastomeric valves through the film, the plurality of elastomeric valves configured to expand in response to a pressure gradient across the film; and   a cover configured to be attached to the tissue site;   wherein the cover and the tissue interface are assembled in a stacked relationship with the cover configured to be attached to an attachment surface adjacent to the tissue site.   
     
     
         78 . The apparatus of  claim 77 , wherein the film is configured to be interposed between the manifold and the tissue site. 
     
     
         79 . The apparatus of  claim 77 , wherein the film comprises a polymer film having an area density less than 30 grams per square meter. 
     
     
         80 . The apparatus of  claim 77 , wherein the film comprises a polymer film having a contact angle with water greater than 90 degrees. 
     
     
         81 . The apparatus of  claim 77 , wherein the film has a surface with height variations not exceeding 0.2 millimeters over 1 centimeter. 
     
     
         82 . The apparatus of  claim 77 , wherein the tissue interface further comprises a sealing layer adjacent to the film and configured to contact the tissue site, and at least one aperture in the sealing layer fluidly coupled to at least one of the elastomeric valves in the film. 
     
     
         83 . The apparatus of  claim 82 , wherein at least one of the apertures is configured to expose at least some of the film to the tissue site. 
     
     
         84 . The apparatus of  claim 82 , wherein at least one of the apertures is configured to expose at least some of the elastomeric valves to the tissue site. 
     
     
         85 . The apparatus of  claim 82 , wherein at least some portion of the film is exposed through at least one of the apertures. 
     
     
         86 . The apparatus of  claim 82 , wherein at least some portion of the elastomeric valves are exposed through the apertures in the third layer. 
     
     
         87 . A dressing for treating a tissue site with negative pressure, the dressing comprising:
 a first layer comprising a film having a flat surface texture;   a second layer adjacent to the first layer, the second layer comprising a manifold; and   a plurality of fluid restrictions through the film, the plurality of fluid restrictions configured to be responsive to a pressure gradient across the fluid restrictions.   
     
     
         88 . A system for treating a tissue site, the system comprising:
 the dressing  claim 70 ; and   a negative-pressure source fluidly coupled to the dressing or apparatus.   
     
     
         89 . The system of  claim 88 , further comprising a fluid container fluidly coupled between the dressing and the negative-pressure source. 
     
     
         90 - 91 . (canceled) 
     
     
         92 . A method of treating a surface wound with negative pressure, the method comprising:
 applying the dressing of  claim 70  to a tissue site;   sealing the dressing or apparatus to epidermis adjacent to the tissue site;   fluidly coupling the dressing or apparatus to a negative-pressure source; and   applying negative pressure from the negative-pressure source to the dressing or apparatus.   
     
     
         93 - 94 . (canceled) 
     
     
         95 . The method of  claim 92 , wherein applying the dressing comprises disposing at least part of the dressing across an edge of the surface wound. 
     
     
         96 . The method of  claim 92 , wherein applying negative pressure opens the fluid restrictions. 
     
     
         97 . The method of  claim 96 , further comprising reducing negative pressure from the negative-pressure source, wherein reducing negative pressure closes the fluid restrictions. 
     
     
         98 - 99 . (canceled) 
     
     
         100 . A method of promoting granulation in a surface wound, the method comprising:
 applying a dressing to the surface wound, the dressing comprising a manifold having a first surface and a second surface opposite the first surface, and a perforated polymer film covering at least the first surface; and   applying negative pressure from a negative-pressure source to the dressing and promoting granulation;   wherein the perforated polymer film is hydrophobic and is applied to the surface wound.   
     
     
         101 - 102 . (canceled) 
     
     
         103 . The method of  claim 100 , further comprising:
 sealing the perforated polymer film to the surface wound and covering at least a portion of a periwound adjacent to the surface wound;   attaching the cover to epidermis around the perforated polymer film; and   fluidly coupling the dressing to the negative-pressure source.   
     
     
         104 . The method of  claim 100 , wherein the dressing remains on the surface wound for at least 5 days. 
     
     
         105 - 111 . (canceled)