HK1090580B - Negative pressure wound treatment dressing - Google Patents

Description

Negative pressure wound therapy dressing

This application claims priority from U.S. provisional patent application No. 60/489,344 filed on 22/7/2003 under 37 c.f.r.1.53(b) (2).

Technical Field

The present invention relates to the treatment of open chronic wounds as well as burns and epidermal grafts. More particularly, the present invention relates to dressings for wound treatment of extremities (e.g., the heel of a human foot) by means of negative pressure wound therapy.

Background

Negative pressure wound therapy has been utilized for the treatment of wounds without dressing and has been passed by Kinetic Concepts (San Antonio, Texas) through its patent v.a.c.The production line is commercialized. In fact, it is "Vacuum Assisted close" by Assignee or its parent"(or" v.a.c.") marking the application of commercially available negative gauge pressure wounds, typically involving simultaneous removal of excess fluid, mechanical wound retraction, is generally accomplished by means of a polymeric foam and occlusive drape dressing in fluid communication with a source of negative pressure. In this manner, negative pressure wound therapy enhances the body's natural inflammatory processes, such as edema production due to increased blood flow absent the necessary vascular structure for normal venous return, while alleviating many of the known inherent side effects. As a result, negative pressure wound therapy has been highly successful in promoting wound closure and healing many wounds previously thought largely untreatable.

Many such wounds include pressure sores and stasis ulcers to the lower extremities, particularly the foot. Closure of these wounds is difficult and often impossible using traditional techniques such as skin grafting, sharp debridement or a combination thereof. Failure to close these wounds, which have often occurred for several years, can lead to tissue necrosis and, in many cases, amputation of the limb. The use of negative pressure wound therapy has proven highly successful in closing these wounds. However, treatment of lower extremities using negative pressure wound therapy, particularly for foot wounds, and healing can be difficult, particularly in view of the nature of the wound site. Special care is taken to maintain the dressing on the limb, especially in terms of frequent movement of the foot, and the friction normally 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 can occur during foot movement, which can adversely affect the therapy being administered. For the foregoing reasons, there is a need for a negative pressure wound therapy dressing system that is capable of maintaining negative pressure on limbs that have heretofore been difficult to treat with conventional negative pressure wound therapy dressings. In addition, there is a need for a negative pressure wound therapy dressing system that is capable of maintaining a negative pressure on wounds that are present on highly curvilinear portions of the body, or on portions of the body that are subject to frequent movement or friction with clothing or other external forces.

It is therefore an object of the present invention to provide a negative pressure wound therapy dressing system that provides a way to maintain negative pressure on contoured limbs, such as the foot and, more particularly, the heel.

Summary of The Invention

In accordance with the foregoing objects, the present invention generally comprises a contoured porous pad positioned within an open, contoured wrapping (occlusive) over a wound on a limb such as a human heel. A concave porous pad is placed adjacent to or at the wound site such that the concave pad is enclosed by the occlusive wrapping. The flexible tube is attached to or through an opening of the drape to allow fluid of negative pressure to communicate from a negative pressure source connected to an opposite end of the flexible tube to the concave pad. Negative gauge pressure is communicated from the source, through the tube, through the occlusive wrapping aperture, such that negative gauge pressure is applied to the wound on the limb. The contoured porous pad is used to polytype negative pressure from a location remote from the wound site to the concave pad at the wound site. Such an arrangement allows the tube to be attached to the dressing of the invention at a location that is least likely to be removed during normal ambulatory activity of the patient.

The securing portion is formed on the outer edge of the occlusive wrapping to form an airtight seal over the wound. Such a fixation section may be an adhesive applied to the occlusive wrapping for fixation to the normal area of tissue or skin. The adhesive is applied to the perimeter of the occlusive wrapping so as to form a pocket when the occlusive wrapping is secured to the concave pad.

A collection canister is provided between the negative pressure source and the occlusive drape for collecting any exudates withdrawn from the wound during application of the negative pressure.

The tube is connected to the drape and pad through an opening in the drape, or through a flanged tube connection, as has been described in U.S. patent 6,345,623 entitled "surgical drape and suction head for wound treatment" by Heaton et al, which is incorporated herein by reference as if fully set forth. Alternative embodiments allow the tube to be placed or embedded in a concave pad.

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 embodiments.

Drawings

These and other features and advantages of the present invention will now be described with reference to the accompanying drawings of certain preferred embodiments, which are intended to illustrate and not to limit the invention, and in which like reference numerals refer to like parts, and in which:

FIG. 1A is an exploded view of the closure package of the present invention;

FIG. 1B is an orthogonal plan view of the occlusive wrapping of the present invention;

FIG. 2 is an orthogonal view of a occlusive wrapped fluid manifold of the present invention;

FIG. 3A is a perspective view of a contoured pad of the present invention;

FIGS. 3B and 3C are cross-sectional views of a contoured pad of the present invention;

FIG. 3D is a top plan view of the contoured pad of the present invention;

4A-4G are perspective views of the negative pressure wound therapy dressing system illustrating the steps of applying the dressing system to a wound on the heel; and

fig. 5 is an orthogonal plan view pattern view of the occlusive wrapping of the present invention folded along its midline.

Detailed Description

While those of ordinary skill in the art will readily recognize many alternative embodiments, particularly in light of the description provided herein, this detailed description is exemplary of the preferred and alternative embodiments of the present invention, the scope of which is limited only by the claims set forth herein.

The details of preferred embodiments of the invention are set forth 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 particularly to fig. 1, the major components of an occlusive wrapping 10 of a negative pressure dressing system operating in accordance with the present invention are shown. The occlusive wrapping 10 includes a fluid manifold 14(fluid manifold) embedded within an occlusive drape 16. The occlusive drape 16 is preferably made of a transparent vapor permeable polyurethane material. The drape 16 is made up of a wound facing layer 16a and an outer layer 16b that are sealed along their peripheries to secure the fluid manifold 14 within the wound facing layer 16a and outer layer 16b of the drape 16. A plurality of apertures 19 are formed along the wound contact region 17 of the wound facing layer 16a to allow fluid communication through the fluid manifold 14. The fluid manifold 14 allows the fluid communication port 18 to be secured at a location remote from the wound site. The type of wound that is desired to be treated by the present system is typically located at a location where it is sometimes difficult to maintain a reduced pressure using conventional negative pressure wound therapy techniques described herein. The occlusive wrapping 10 of the present invention overcomes this difficulty by communicating negative pressure along the manifold 14, and more particularly along the fluid manifold 14 of the occlusive wrapping 10, as best shown in fig. 2.

Fig. 2 illustrates an alternative embodiment of the fluid manifold 14 of the occlusive wrapping 10. The fluid communication port 18 is connected to a receiving site 20, which is preferably a circular foam portion approximately the size of the fluid communication port 18. A fluid communicator arm 22 extends distally from the receiving site 22 to the wound contact area 17. The fluid communicator arm 22 terminates in a ring 24 having an opening for viewing the wound periphery. In an alternative embodiment, the fluid-flow fingers extend distally from the fluid-flow arm 22.

A contoured pad 26, as illustrated in fig. 3A-3D, is utilized as a wound contact drape to prevent unwanted adhesions, to direct fluid away from the wound through pores within the pad 26, and to apply contraction forces to the wound edges as negative pressure is applied through the manifold 14 and to the pad 26. The contoured pad 26 and fluid manifold 14 of occlusive wrapping 10 are preferably made of a porous polymeric foam material such as polyurethane or polyvinyl alcohol foam. The pad 26 is preferably configured in an oval shape as shown in fig. 3D, but may also be more symmetrically circular to accommodate a more uniform wound.

In practice, as shown in fig. 4A-4G, the contoured pad 26 is trimmed to the size of the wound distribution and placed over the wound, which may be on the heel of the foot, and between the wound and the fluid manifold 14. The pad 26 may be secured to the wound site by an adhesive strip 28, as shown in fig. 4A, or by other means known in the art. In a preferred embodiment, the adhesive strip is constructed of the same vapor permeable polyurethane material as the occlusive drape 16, with an adhesive applied to one side for securing the strip to the pad 26 and the normal skin surrounding the wound.

When the occlusive wrapping 10 is folded along its midline, as shown in fig. 5, the occlusive wrapping 10 forms a pouch 30 and the lower edges 31 are joined together at 33. In practice, the pouch 30 is placed over the wound and contoured pad 26, as shown in fig. 4B and 4C. A finger grip 36a is provided to facilitate grasping the pouch 30 and holding it in place when the liner 35 is removed to expose an adhesive backing on layer 16 b. The edges 32a, 32b of the pouch 30 are brought into contact with the normal skin surrounding the wound by means of an adhesive backing. A removable liner 35 is removed, beginning with finger tab 35a, exposing the adhesive, as shown in fig. 4C. The removable liner 35 may be statically adhered to the adhesive backing to protect the adhesive during handling.

As shown in fig. 4D, a second removable liner 37 is adhered to the receiving site 20 to protect the adhesive on the wound facing layer 16a along the receiving site 20 during treatment, and is removed before the receiving site 20 is adhered to the normal skin area 40 away from the wound site to prevent removal of the fluid communication port 18 during patient movement, as shown in fig. 4E. A removable, protective liner 36 may be placed over the occlusive drape 16 to provide rigidity to the manifold during handling and removed after the pouch 30 is secured to the wound site, as shown in fig. 4F.

A fluid communication port 18 is placed over the receiving site 20 and is also secured in place by an adhesive contact surface on the communication port 18. As is known in the art of negative pressure wound therapy, a fluid communication device 42, such as flexible silicon tubing, communicates negative pressure to the wound from a negative pressure source 44, such as a portable pump. A collection canister 46 is positioned in line between the negative pressure source 44 and the fluid communication means 42 to collect any exudate that may be aspirated from the wound.

Although the present invention has been described herein with reference to certain preferred embodiments, these embodiments are presented by way of example only, and are not intended to limit the scope of the invention. Many other variations are possible, which will be apparent to those skilled in the art. Accordingly, the scope of the invention should be characterized only in accordance with the following claims.

Claims (5)

1. A wound dressing for use under negative pressure, comprising:

a contoured porous pad adapted for placement over a wound;

a occlusive wrapping adapted to be placed over and around a contoured porous pad, wherein said occlusive wrapping comprises:

a fluid manifold formed from porous polymer foam and having a receiving location and fluid flow-through arms extending from the receiving location,

a occlusive drape comprising a wound facing layer and an outer layer enclosing the fluid manifold, and an opening formed in the outer layer and substantially aligned with the receiving site, wherein the wound facing layer comprises a plurality of apertures formed along a wound contact area, and

an adhesive on at least one edge of the occlusive drape for sealing the occlusive wrapping to the surrounding wound area; and

a fluid communication port through at least one layer of the occlusive drape for communicating fluid from the fluid manifold to a source of negative pressure.

2. The wound dressing according to claim 1, wherein the flow-through arms form contiguous loops.

3. The wound dressing according to claim 2, wherein the flow-through arm further comprises a flow-through finger element extending distally from the flow-through arm.

4. A wound dressing for use under negative pressure, comprising:

a contoured porous pad adapted to be placed over a wound;

an occlusive wrapping adapted to be placed on and around said contoured pad, wherein said occlusive wrapping comprises:

a fluid manifold formed from porous polymer foam and having a receptacle for receiving a fluid flow port and fluid flow member arms extending from the receptacle,

a transparent occlusive drape enclosing said fluid manifold such that said fluid manifold is embedded within said transparent occlusive drape, an

An adhesive on at least one edge of the transparent occlusive drape for sealing the occlusive wrapping to the surrounding wound area;

a fluid communication port through at least one layer of the occlusive drape for communicating fluid from the fluid manifold to a source of negative pressure;

and wherein the fluid communicator arm terminates in a loop to allow viewing of the wound area through the occlusive drape.

5. A wound dressing for use under negative pressure, comprising:

a contoured pad adapted to be placed over a wound;

an occlusive wrapping adapted to be placed on and around said contoured pad, wherein said occlusive wrapping comprises:

a fluid manifold having a receiving location and a fluid-flow-through arm, the fluid-flow-through arm being fluidly connected to the receiving location, the receiving location for receiving a fluid-flow through,

a transparent occlusive drape surrounding the fluid manifold such that the fluid manifold is embedded within the occlusive drape, an

An adhesive on at least one edge of the occlusive drape for sealing the occlusive wrapping to a surrounding wound area,

wherein the fluid communicator arms extend distally from the receptacle to form an adjoining loop to allow viewing of the wound area through the occlusive drape,

wherein the occlusive wrapping has lower edges that are joined to form a pouch; and

a fluid communication port through at least one layer of the occlusive drape for communicating fluid from the fluid manifold to a source of negative pressure.