Medical dressings, systems, and methods employing sealants

Abstract

According to an illustrative embodiment, a system for treating a wound at a tissue site of a patient comprising a reduced-pressure source to supply reduced pressure, a drape adhering to the tissue site to cover the wound where possible leak passages between the drape and the tissue site may occur, and a seal disposed between the drape and the tissue site, is disclosed. The seal is adapted to react with a fluid to form a sealant substantially filling the passages in response to air leaking through the passages from outside the drape when reduced pressure is applied to the wound. According to another illustrative embodiment, a method for sealing a drape to a tissue site for treating a wound at the tissue site comprising applying the drape to cover the tissue site whereby passages are formed between the drape and the tissue site, positioning a seal between the drape and the tissue site wherein the seal is adapted to react with a fluid to form a sealant for substantially filling the passages, is also disclosed.

1 . A system for treating a wound at a tissue site, the system comprising:
 a pressure source to supply reduced pressure;   a manifold in fluid communication with said pressure source to provide reduced pressure to the wound;   a drape adhering to the tissue site to cover the wound and said manifold, there being passages between said drape and the tissue site; and,   a seal disposed between said drape and the tissue site, said seal adapted to react with a fluid to form a sealant substantially filling the passages in response to air leaking through the passages from outside said drape when said manifold provides reduced pressure to the wound.   
     
     
         2 . The system of  claim 1 , wherein said seal contains an isocyanate material and the fluid is water vapor contained in the air that leaks from outside said drape to contact said seal. 
     
     
         3 . The system of  claim 1 , wherein said seal is a water-sensitive polymer and the fluid is water vapor contained in the air that leaks from outside said drape to contact said seal. 
     
     
         4 . The system of  claim 3 , wherein the water-sensitive polymer is polyacrylate, polyvinylpyrrolidone, polyvinyl alcohol, alginates, or carboxymethyl cellulose. 
     
     
         5 . The system of  claim 1 , wherein said seal is a water-sensitive polymer and the fluid is exudates from the wound that contact said seal. 
     
     
         6 . The system of  claim 1 , wherein said seal is a water-sensitive polymer and the fluid is water applied to said seal. 
     
     
         7 . The system of  claim 1 , wherein said seal is a water-sensitive material that liberates gases to form the sealant and the fluid is water vapor contained in the air that leaks from outside said drape to contact said seal. 
     
     
         8 . The system of  claim 7 , wherein the water-sensitive material is a metal hydride or a metal carbide. 
     
     
         9 . The system of  claim 1 , further comprising a fluid supply for providing the fluid to the tissue site. 
     
     
         10 . The system of  claim 9 , wherein the seal is polyurethane, acrylic, or acetate and the fluid is a solvent. 
     
     
         11 . The system of  claim 10 , wherein the solvent is alcohol, glycol, polyethylene glycol, or glycerine. 
     
     
         12 . The system of  claim 1 , wherein the fluid is a gas drawn into said manifold in response to application of reduced pressure to the tissue site, wherein the gas reacts with said seal to expand said seal to form the sealant. 
     
     
         13 . The system of  claim 1 , wherein the fluid is pre-applied to the tissue site. 
     
     
         14 . The system of  claim 1 , wherein said seal is a material comprising polymer spheres responsive to reduced pressure and expanding in response to a pressure differential provided by said pressure source to form the sealant. 
     
     
         15 . The system of  claim 1 , wherein said seal has a first side and a second side facing the tissue site, further comprising:
 a release liner covering at least one of the first side and the second side of the seal, the release liner adapted to prevent said seal from forming the sealant prior to application of the seal and the drape to the tissue site.   
     
     
         16 . The system of  claim 1 , wherein said seal expands to form the sealant for filling the passages. 
     
     
         17 . The system of  claim 1 , wherein the sealant at least partially fills the passages formed by a fold in said drape to substantially seal the passages. 
     
     
         18 . The system of  claim 1 , wherein the seal forms an annulus at least partially surrounding the wound at the tissue site. 
     
     
         19 . The system of  claim 1 , wherein said drape has a first side and a second side facing the tissue site, and wherein said seal substantially covers the second side of said drape. 
     
     
         20 . The system of  claim 1 , wherein the sealant is adhesive and operable to cause said drape to adhere to the tissue site. 
     
     
         21 . An apparatus for treating a wound at a tissue site, the apparatus comprising:
 a manifold adapted to provide reduced pressure to the wound;   a drape having an adhesive surface for adhering to the tissue site to cover the wound and said manifold, there being passages between said drape and the tissue site; and,   a seal adjacent the adhesive surface of said drape, said seal disposed between said drape and the tissue site when applied to the tissue site and transformable to form a sealant substantially filling the passages between said drape and the tissue site when said manifold provides reduced pressure to the wound;   whereby air leaks from outside said drape are reduced when said manifold provides reduced pressure to the wound.   
     
     
         22 . The apparatus of  claim 21 , wherein said seal contains an isocyanate material reactive with water vapor and transforms to form the sealant in response to water vapor contained in air when air leaks from outside said drape and contacts said seal. 
     
     
         23 . The apparatus of  claim 21 , wherein said seal is a water-sensitive polymer that transforms to form the sealant in response to water vapor contained in air when air leaks from outside said drape and contacts said seal. 
     
     
         24 . The apparatus of  claim 23 , wherein the water-sensitive polymer is polyacrylate, polyvinylpyrrolidone, polyvinyl alcohol, alginates, or carboxymethyl cellulose. 
     
     
         25 - 40 . (canceled) 
     
     
         41 . A method for sealing a drape to a tissue site for treating a wound at the tissue site, the method comprising:
 applying the drape to cover the tissue site whereby passages are formed between the drape and the tissue site;   positioning a seal between the drape and the tissue site wherein the seal is adapted to react with a fluid to form a sealant for substantially filling the passages;   applying reduced pressure to the tissue site; and,   applying the fluid to the seal to form the sealant, whereby the sealant substantially fills the passages and reduces air leaking from outside said drape when reduced pressure is applied to the tissue site.   
     
     
         42 - 50 . (canceled) 
     
     
         51 . A method for treating a tissue site of a patient, the method comprising:
 applying a dressing to the tissue site, the dressing comprising:
 a seal having a first side and a second, tissue-facing side, the seal adapted for placement adjacent the tissue site, the seal operable to expand in a presence of a fluid to form a substantially sealed space at the tissue site; and 
 a drape for covering the seal and further forming the substantially sealed space. 
   
     
     
         52 - 58 . (canceled)