Negative pressure wound treatment dressing

A wound treatment dressing for applying negative pressure wound therapy to a wound on an extremity, such as on the heel of a foot. The dressing includes a fluid manifold positioned within a fenestrated drape to form a contoured occlusive wrapping. A contoured porous pad is placed adjacent or within the wound, and is covered by the occlusive wrapping. Flexible tubing is attached to or through a port to allow fluid communication of negative pressure to the contoured pad from a source of negative pressure. The negative pressure is communicated from the source, through the tube, through the fluid manifold, and through the fenestrations of the occlusive wrapping, to the wound. The fluid manifold conducts the negative pressure from a position away from the wound site to the contoured pad at the wound site.

FIELD OF THE INVENTION

This invention relates to the treatment of open, chronic wounds, as well as burns and skin grafts. More specifically this invention relates to dressings for the treatment of wounds to the extremities, such as the heel of a human foot, by means of negative pressure wound therapy.

BACKGROUND OF THE INVENTION

Negative pressure wound therapy has been utilized for the treatment of open wounds and has been commercialized by Kinetic Concepts, Inc. of San Antonio, Tex., by its proprietary V.A.C.® product line. In practice, the application to a wound of negative gauge pressure, as commercialized by Kinetic Concepts, Inc. under the designation “VACUUM ASSISTED CLOSURE” (or “V.A.C.”) therapy, typically involves the mechanical-like contraction of the wound with simultaneous removal of excess fluid, which is often accomplished by means of a polymer foam and occlusive drape dressing in fluid communication with a negative pressure source. In this manner, negative pressure wound therapy augments the body's natural inflammatory process while alleviating many of the known intrinsic side effects, such as the production of edema caused by increased blood flow absent the necessary vascular structure for proper venous return. As a result, negative pressure wound therapy has been highly successful in the promotion of wound closure, healing many wounds previously thought largely untreatable.

Many of these wounds include decubitus and venous stasis ulcers to the lower extremities, especially the foot. Closure of these wounds has been difficult and often times impossible using traditional techniques, such as skin grafting, sharp debridement, or combinations thereof. Failure to close these wounds, which have often been present for several years, can lead to necrotizing of the tissue, and in many cases amputation of the extremity. Use of negative pressure wound therapy has proven highly successful in closing these wounds. However, treatment of the lower extremities with negative pressure wound therapy, especially to wounds of the foot and heel can be difficult, especially considering the nature of the location of the wound. Particular concern arises with maintaining the dressing on the extremity, especially in light of the frequent movement of the foot, and friction often associated with foot coverings, including socks, stockings, and shoes. Of particular concern, is the ability to maintain a negative pressure at the wound site when the dressing is in place, as air leaks may occur during movement of the foot, which can adversely affect the therapy being administered.

For the foregoing reasons, there is a need for a negative pressure wound treatment dressing system that is capable of maintaining a negative pressure over an extremity that has heretofore been difficult to treat using traditional negative pressure wound therapy dressings. Additionally, there is a need for a negative pressure wound treatment dressing system that is capable of maintaining a negative pressure over a wound which exists in a highly contoured part of the body, or a portion of the body that undergoes frequent movement or friction against clothing or other outside forces.

It is therefore an object of the present invention to provide a negative pressure wound treatment dressing system that provides a means for maintaining a negative pressure over a contoured extremity, such as the foot, and more specifically the heel of the foot.

SUMMARY

In accordance with the foregoing objects, the present invention generally comprises a fenestrated and contoured occlusive wrapping having a fluid manifold, a receiving site, fluid communicator arms extending from the receiving site, and an occlusive drape enclosing the fluid manifold. The occlusive drape generally includes a wound facing inner drape and an outward facing outer drape, and an aperture substantially aligned with the receiving site. A concave porous pad is placed adjacent or within a wound on an extremity, such as the heel of a foot, and is covered by the occlusive drape. Flexible tubing may be attached to or through the aperture, so as to allow for fluid communication of negative pressure to the porous pad from a source of negative pressure connected to an opposite end of the flexible tubing. The negative gauge pressure is communicated from the source, through the tube, through the fluid manifold in the occlusive drape, and through fenestrations in the occlusive drape, such that negative gauge pressure is applied to the wound. The fluid manifold serves to conduct the negative pressure from a position away from the wound site to the contoured porous pad at the wound site. Such an arrangement allows for the tubing to connect to the occlusive drape of the present invention at a position least likely to be dislodged during normal ambulation of the patient.

Attachment means are formed on the outer edges of the occlusive drape to form an airtight seal over the wound. Such attachment means may be an adhesive coated on the occlusive drape for attachment to an intact area of tissue or skin. The adhesive is coated on the perimeter edge of the occlusive drape such that a pouch is formed when the occlusive drape is secured over the porous pad.

A collection canister is provided between the negative pressure source and the occlusive drape for collecting any effluents that may be drawn from the wound during application of negative pressure.

The tubing is connected to the occlusive wrapping and pad through an aperture in the outer layer of the wrapping, or through a flanged tubing connector as has been described in U.S. Pat. No. 6,345,623, entitled “Surgical drape and suction head for wound treatment,” to Heaton, et al., the disclosure of which is incorporated herein by reference as though fully set forth. Alternative embodiments allow the tubing to be placed within or embedded in the fluid manifold.

The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or by modifying the invention as will be described. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the following Detailed Description of the Invention, which includes the preferred embodiment.

DETAILED DESCRIPTION

Although those of ordinary skill in the art will readily recognize many alternative embodiments, especially in light of the illustrations provided herein, this detailed description is exemplary of the preferred embodiment of the present invention as well as alternate embodiments, the scope of which is limited only by the claims that may be drawn hereto.

The details of the preferred embodiments of present invention are graphically and schematically illustrated in the accompanying drawings. Like elements in the drawings are represented by like numbers, and any similar elements are represented by like numbers with a different lower case suffix.

Referring now toFIGS. 1A and 1Bin particular, there is illustrated the primary components of the occlusive wrapping10of the negative pressure dressing system that operates in accordance with the present invention. The occlusive wrapping10includes of a fluid manifold14enclosed within inner drape16aand an outer drape16b. Each of these drapes16aand16bare preferably made of a clear vapor permeable polyurethane material. The wound facing layer of inner drape16aand the outward facing layer of outer drape16bare sealed along their periphery to secure the fluid manifold14between the inner drape16aand the outer drape16b. Inner drape16aincludes fenestrations19in a wound contact region17, so as to allow for fluid communication through the inner drape16ato the fluid manifold14. Outer drape16bincludes an aperture16csubstantially aligned with receiving site20, through which tubing may fluidly communicate with the receiving site20of the fluid manifold14, so as to allow for fluid communication of negative pressure to a porous pad from a source of negative pressure connected to an opposite end of the tubing (as shown inFIG. 4G). The fluid manifold14illustrated inFIG. 1Aprovides an extension region21and fluid communicator arms22that allows for attachment of a fluid communication port (not shown) at a position away from the wound site. The type of wounds desired to be treated by the present system are often situated at a position that has, at times, been difficult to maintain a reduced pressure using traditional negative pressure wound therapy techniques described herein. The occlusive wrapping10of the present invention overcomes this difficulty by communicating the negative pressure along the fluid manifold14of the occlusive wrapping10.FIG. 1Bshows essentially the same components of the occlusive wrapping10as shown inFIG. 1A. In this view ofFIG. 1Bfrom the wound side of the wrapping, wound contact region17on inner drape16a(shown partly in section) is shown to be bordered by portions of outer drape16bcovered over with removable liner components35, as well as second removable liner37. Protective liner36(only minimally exposed in this view by partial section of inner drape16aand outer drape16b) supports outer drape16bof occlusive wrapping10.

FIG. 2illustrates the fluid manifold14. As described above, the fluid communication port (not shown) of the overall system is adapted to be attached to a receiving site20of the manifold14. The receiving site20is most preferably a circular shaped foam section of the manifold14that is approximately the size of the fluid communication port. Fluid communicator arms22extend distally from the receiving site20area of the fluid manifold14into the wound contact regions17. In the embodiment illustrated inFIG. 2, the extension region21is interposed between the receiving site20and the fluid communicator arms. The fluid communicator arms22in a first embodiment terminate in loops24, having openings for viewing the wound perimeter when, as in the preferred embodiment, inner and outer drapes16aand16bcomprise a transparent material. In an alternative embodiment (not shown), fluid communicator arms22may terminate in fingers that extend distally from the fluid communicator arms22without forming loops.

A contoured pad26as illustrated inFIGS. 3A-3Dis utilized as a wound contact screen to prevent unwanted adhesions, direct fluid away from the wound through pores within the pad26, and exert contracting forces on the wound margins as negative pressure is applied through the manifold14and to the pad26. The contoured pad26and fluid manifold14of the occlusive wrapping10are preferably made of a porous polymer foam material, such as polyurethane or polyvinyl alcohol foam. The pad26is preferably constructed into an elliptical shape as illustrated inFIG. 3D, but may also be more symmetrically circular to accommodate more uniform wounds.

In practice, the contoured pad26is trimmed to the areal dimensions of the wound and is placed in the wound, which may be on the heel of a foot, and between the wound and the fluid manifold14, as illustrated inFIGS. 4A-4G. The pad26may be secured to the wound site by an adhesive strip28, as shown inFIG. 4A, or by other means known in the art. In the preferred embodiment, the adhesive strip is constructed of the same vapor permeable polyurethane material as the inner and outer drapes16aand16bof the occlusive wrapping10having an adhesive coated on one side for securing the strip to the pad26and the intact skin surrounding the wound.

The occlusive wrapping10forms a pouch30when it is folded along its centerline and the lower edges31are bonded together at33as shown inFIG. 5. In practice, the pouch30is placed over the wound and contoured pad26, as illustrated inFIGS. 4B and 4C. A fingerhold39is provided as an extension of protective liner36to facilitate grasping the pouch30and holding it in place as the removable liner components35are removed to expose adhesive backing on outer drape16b. The edges32aand32b(shown inFIG. 4B) of the pouch30are brought into contact with the intact skin surrounding the wound by means of this adhesive backing. A removable liner35(visible through the partial section of protective liner36) is pulled off, for example, starting at finger tab extension41of removable liner35(shown bent back for grasping inFIG. 5), exposing the adhesive, as shown inFIG. 4C. The removable liners35may be statically adhered to the adhesive backing on outer drape16bto protect the adhesive during handling.

As illustrated inFIGS. 4D and 4E, a second removable liner37is adhered to the wound facing inner drape16ato protect the adhesive on the wound facing inner drape16a. The liner37is removed prior to adhesion of the wound facing inner drape16ato a region40of intact skin away from the wound site, so as to help prevent dislodgement of the fluid communication port18(shown inFIG. 4G) during movement of the patient. Protective liner36in a preferred embodiment, is overlaid on the outer drape16b(as illustrated inFIG. 1), so as to provide partial rigidity to the occlusive wrapping10and its fluid manifold14during handling. The liner36is removed after securing the pouch30to the wound site, as shown inFIG. 4F.

Reference is finally made toFIG. 4Gwhich shows how a fluid communication port18is positioned over the receiving site20, and is secured in place also by means of an adhesive contact surface on the communication port18. As known in the art of negative pressure wound therapy, a fluid communication means42, such as a flexible silicone tube, communicates negative pressure to the wound from a negative pressure source44, such as a portable pump. A collection canister46is positioned in line between the negative pressure source44and the fluid communication means42to collect any exudates that may be drawn from the wound.

While the invention has been described herein with reference to certain preferred embodiments, theses embodiments have been presented by way of example only, and not to limit the scope of the invention. Many other variations are possible, which would be obvious to one skilled in the art. Accordingly, the scope of the invention should be identified only in accordance with the claims that follow.