Wound dressing port and associated wound dressing

(54) Title: WOUND DRESSING AND ASSOCIATED WOUND DRESSING (30) Unionist Priority: 07/03/2008 us 12 / 044,051 (73) Holder (s): Tyco Healthcare Group LP (72) Inventor (s): MarkA. Vess (57) Summary: wound dressing door and ASSOCIATED WOUND dressing. The present invention relates to a wound dressing for use in a therapeutic vacuum wound treatment that includes a backing layer to position over a wound to define a reservoir in which a reduced pressure can be maintained on the wound. A portal member affixed to the backing layer provides a connection to a source of reduced pressure through an opening in an ambient surface. A primary port extends between the opening and a primary opening on a reservoir surface to provide fluid communication between the reservoir and the reduced pressure source. At least one supplementary port establishes fluid communication between the primary port and a supplementary opening in the reservoir surface that is distinct and substantially spaced from the primary opening.

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ΡΙ0900516-1

Invention Patent Descriptive Report for Wound Dressing Door and Associated Wound Dressing.

Technical Field

The present invention generally relates to a wound dressing for treating an open wound with a vacuum wound therapeutic treatment. In particular, the invention relates to a dressing having a portal member providing a connection to a vacuum system such that a reservoir over the wound can be evacuated.

Background to the Prior Art

The body's natural wound closure process is a series of complex events that begin at the time of damage. Initially, the body reacts by sending proteins and other factors to the wound through a bloodstream to minimize damage. The blood clots to prevent blood loss while the cells bring in bacteria and debris to take them away from the wound site. Then, the body begins self-repair at a wound closure stage often referred to as the proliferative phase. This phase is characterized by the deposition of granulation tissue in the wound bed. The granulation tissue provides a base structure on which cells can migrate internally from the periphery to close the wound. Finally, the process ends when collagen provides resistance to new tissue over time, often forming a scar.

One technique to promote the natural wound closure process, particularly, but not exclusively during the proliferative phase, is known as vacuum wound therapy (VWT). Application of reduced pressure, for example, subatmospheric, to a reservoir located over a wound has been found to assist in wound closure. The reduced pressure can be effective in promoting blood flow to the area to stimulate the formation of granulation tissue and the migration of healthy tissue over the wound by the natural process. Also, reduced pressure can assist in removing fluids that exude from the wound, which can inhibit the growth of bacteria. This technique has proven effective for chronic or non-healing wounds, but it has also been used for other purposes such as post-operative wound care.

The general VWT protocol provides for the introduction of an absorbent filler material such as non-cross-linked foams, non-woven fabrics or gauze, into the wound to absorb exudates. The wound and absorbent filler material can then be coated with a flexible covering layer such as a polymeric film, for example, to establish a vacuum reservoir over the wound where a reduced pressure can be applied by individual evacuation procedures or cyclical. To allow the reduced pressure to remain over time, the covering layer may include an adhesive periphery that forms a substantially hermetic seal to the fluid with healthy skin surrounding the wound.

Although some procedures may employ a micro pump contained within the vacuum reservoir, most VWT treatment applies reduced pressure using an external vacuum source. Thus, fluid communication between the vacuum source and the reservoir must be established. For this purpose, a cover layer will often include a connector or portal member to which air tubes from an external vacuum system can be connected.

An aspect of interest in a VWT treatment is the migration of the load material and wound exudates in the direction of airflow when reduced pressure is applied. These substances can be deposited on surfaces within a portal member, for example, and excessive time causes the obstruction or complete occlusion of these portal members. This phenomenon may limit the level of exudate flow from the wound area or may even prohibit the application of reduced pressure to the wound area, thereby limiting or frustrating the effectiveness of the VWT treatment. Consequently, a need exists for an appropriate dressing for use in a VWT procedure.

summary

The present invention describes a wound dressing for use in a vacuum wound therapeutic treatment. The wound dressing includes a support layer for positioning on a wound to define a reservoir in which reduced pressure can be maintained on the wound. A portal member is affixed to the support layer in such a way that an ambient surface of the portal member can be fluidly isolated from the reservoir surface of the portal member. The backing layer defines a boundary between the ambient surface and the reservoir surface when the backing layer is positioned over a wound. The portal member comprises a primary door that extends between an opening on the ambient surface and a primary opening on the reservoir surface. The opening is adapted for connection to a suction device and the primary opening is adapted to establish fluid communication with the reservoir. The portal member further comprises at least one supplementary port establishing fluid communication between the primary port and the supplementary opening in the reservoir surface. The supplementary opening is distinct and substantially spaced from the primary opening.

The portal member can include a plurality of supplementary ports extending radially outward from the primary port. The primary and supplementary openings can be distributed substantially over the entire reservoir surface. They can be molded from a flexible or elastomeric polymeric material and can include a fixing flange adapted for connecting an adhesive coated film.

The support layer of the wound dressing may comprise a flexible polymeric membrane. The backing layer may include an adhesive coating adapted to affix the backing layer over the wound and provide a substantially hermetic seal to the fluid around the perimeter of the wound. The adhesive coating can be interrupted in such a way that an intermediate portion of the backing layer remains uncoated.

According to another aspect of the invention, a vacuum wound therapy system includes a contact layer and an absorbent load positioned on a wound bed and a portal member affixed to a support layer positioned on the wound bed for define a vacuum reservoir. The portal member includes a primary door that extends between an opening on an ambient surface and a primary opening on a reservoir surface, and at least one supplementary door extending between the primary door and a separate and substantially spaced supplemental opening. first opening.

The contact layer can be formed of a tapered opening film to promote unidirectional flow of exudates from the wound. The absorbent filler material may include a single strand of a polyolefin filament. Also, a vacuum system in fluid communication with the vacuum reservoir can include a vacuum source, a collection can box and a one-way valve.

Brief Description of Drawings

The attached drawings, which are incorporated into and constitute a part of this specification, illustrate the embodiments of the present invention and, together with the detailed description of the embodiments given below, serve to explain the principles of the invention.

Figure 1 is a developed perspective view of a vacuum wound therapy system in accordance with the present invention;

Figure 2 is an orthographic view of the side facing the wound of the portal member of Figure 1;

Figure 3 is a cross-sectional view taken along line 3 - 3 of Figure 2;

Figure 4 is a cross-sectional view of the vacuum wound therapy system of Figure 1 installed on the wound in a patient; and Figure 5 is a view similar to Figure 4 showing an alternate embodiment of a vacuum wound therapy system.

Detailed Description of Preferred Embodiments

The wound dressing of the present invention promotes wound closure by providing a reservoir over the wound in which reduced pressure can be maintained. The reservoir subjects the wound to subatmospheric pressure to effectively withdraw fluid, including liquid exudates, from the wound without the continuous use of a vacuum pump.

Therefore, vacuum pressure can be applied once or at various intervals depending on the nature and severity of the wound. The use of a wound dressing in this way has been found to provide wound closure by reducing the likelihood of infection, stimulating the deposition of granulation tissue and other beneficial processes. The wound dressing of the present invention includes a support layer affixed to a portal member to enhance the effect of a vacuum wound therapeutic treatment.

The attached figures illustrate exemplary embodiments of the present invention and are referred to the description of the embodiments shown here. In the following, the invention will be described in more detail by explaining the figures in which similar reference numbers represent similar parts over several views.

Referring initially to Figure 1, a vacuum wound therapy system according to the present invention is generally represented as 10 for use on a wound w surrounded by healthy skin. The vacuum wound therapy system 10 includes a vacuum system 12 in fluid communication with a vacuum reservoir 14 (Figure 4) defined by or within the wound dressing 16. The vacuum system 12 includes a vacuum source 18 coupled to the dressing 16 via a one-way valve 20 and a suction device such as vacuum tube 24. A collection can box 28 can be provided for drainage and separation of waste. The vacuum system 12 is adapted to provide reduced pressure to the appropriate vacuum reservoir 14 to stimulate wound healing w. A more detailed description of an appropriate vacuum system 12 is found in US Patent Application Publication No. 2007/0066946, the total contents of which are incorporated herein by reference.

Wound dressing 16 generally includes a contact layer 34, load 38 and a cover layer 40. Cover layer 40 includes a backing layer 44 and a portal member 46. Portal member 46 is configured to establish the fluid communication between vacuum reservoir 14 and vacuum system 12 by providing an interface for a suction device such as vacuum tube 24. Each wound dressing bed 6 is described in more detail below.

The contact layer 34 can be sufficiently conformable to be positioned in direct contact with an irregularly shaped surface of a wound bed w. A thin film of polyethylene or other non-adherent material can form contact layer 34 to limit load adhesion 38 and other substances on wound w. Openings or perforations in the film allow fluids to pass through the contact layer 34, allowing subatmospheric pressure to penetrate wound w and exudates to flow freely out of wound w. By selecting a suitable film material, the passage of the wound exudate through the contact layer 34 can be controlled so as to be substantially unidirectional to prevent the wound exudate from flowing back into the wound. To promote a unidirectional flow, a tapered open film, such as VENTEX® by Kendall Corp., a division of Colvidien, or films opened by Tredegar Film Products of Richmond, VA, can be selected to form contact layer 34. The unidirectional flow exudates can also be promoted by the selection of other materials including a layer lamination having various absorptive characteristics. An exemplary material, which can be used as a contact layer is available under the XEROFLO® brand by Kendall Corp., a division of Covidien.

The charge 38 can be disposed on the contact layer 34 to fill the wound W to the level of the surrounding healthy skin s. An absorbent material such as non-woven gauze or cross-linked foam can be used for charge 38 to trap any exudate that migrates through contact layer 34. An antimicrobial dressing available under the KERLIX® brand from Kendall Corp., a division of Covidien, can be suitable for use as a charge 38. To prevent sticking to wound w, the load 38 may also comprise a material configured in such a way that any dispersed fibers do not tend to protrude through the openings of the contact layer 34, where they can be engulfed by the newly formed granulation tissue. . A particular type of material that exhibits this characteristic is often referred to as tow. The synthetic fiber manufacturing process often includes an extrusion of indeterminate length of continuous filaments, which are spun together to form fibers. Continuous strands of unwoven filaments are referred to as tow. A simple extension of burlap formed of a hydrophobic material such as polyolefin can be laid on the wound bed w to form a charge 38. This arrangement allows a complete removal of the load 38 when the dressing 16 is changed without redanifying the wound w.

A covering layer 40 can be provided as a single unit including both the bottom layer 44 and the porting member 10 such 46, or, alternatively, these items can be provided individually and assembled at the time of installation on the wound w. The covering layer 40 can be placed on the wound w surrounding the contact layer 34 and the charge 38 here.

The backing layer 44 can be formed of a flexible polymeric membrane or film to serve as a fluid barrier to allow a subatmospheric pressure to be established in the vacuum reservoir 14, and also as a microbial barrier preventing contaminants from invading the area. of the wound. For example, backing layer 44 may comprise a polyurethane film having a thickness of about 20.32 pm at

25.4 pm (0.8 thousand to about 1.0 thousand). Preferably, the backing layer 44 is formed of a vapor permeable membrane joined to promote the exchange of oxygen and wet steam between the wound site and atmosphere. An exemplary material is a transparent membrane available under the trade name POLYSKIN® II from Kendall Corp., a division of Covidien. Other materials that may be suitable for use in a backing layer include thin films available under TEGADERM® names from 3M St. Paul, MN and OPSITE ™ from Smith and Nephew PLC of London, UK.

The backing layer 44 of the covering layer 40 is adapted to extend laterally beyond the perimeter of the wound bed w so as to contact healthy skin s to form a seal thereon.

To form the seal, the backing layer 44 can be equipped with an adhesive coating on all or any suitable portion on one side that faces the wound. The adhesive liner may comprise, for example, a pressure-sensitive, medical-type adhesive adapted to provide a fluid-tight seal and bacteria-tight seal around wound w. Thus, the exudate cannot escape through the edges of the dressing 16 and external air and contaminants do not enter the wound area. To provide such a seal, the adhesive coating can, for example, be in the range of about 25.4 pm to 254 pm (1 mil to 10 mils) in thickness. In general, the high-resistance adhesive can be used to resist inadvertent detachment, rolling or loosening, that is, a failure of the dressing to adhere to it, at the edges of the covering layer 40. The adhesive may include, for example, those adhesives included with the dressing available under the ULTEC® Hydrocolloid brand from Kendall Corp., a division of Covidien.

The support layer 44 includes a connecting region 50 to allow the connection of portal member 46. The connecting region 50 receives a reservoir surface 54 from the portal member 46 to fluidly isolate the surface of the reservoir 54 from an ambient surface. 56 on portal member 46 except through portal member 46. As illustrated in Figures 1 and 4, the connecting region 50 can be adapted to receive the reservoir surface 54 directly in such a way that an adhesive coating on the reservoir surface 54 or the connecting region 50 affixes the portal member 46 to the support layer 44 The support layer 44 defines a boundary between the reservoir surface 54 and the ambient surface 56. This arrangement allows the isolation of the reservoir surface 54 from the reservoir

14, that is, reservoir surface 54 can be disposed outside the reservoir 14. Perforations 58 can be formed through the connective region 50 to allow fluid to be withdrawn from the reservoir 14. Alternatively, as shown in Figure 5, the layer of support 44a may include an entrance 50a sized such that a portal member portion

46a protrudes through the support layer 44a. An appropriately positioned adhesive coating can form a seal between a side facing the wound of the backing layer 44a and an opposing oriented surface of a flange 60a. This arrangement allows the reservoir surface 54a to be positioned within the reservoir 14a fluidly isolating the reservoir surface 54a from the ambient surface 56a. Other arrangements are contemplated for attaching a portal member 46, 46a to a backing layer 44, 44a, which may include other parts such as seal rings (not shown).

The backing layer 44 can include a broken adhesive coating such that only the portions of the backing layer 44 forming a seal are coated. For example, the backing layer 44 may include an adhesive coating band around the periphery to form a seal with the skin and another band close to the connecting region 50 to form a seal with the portal member 46. An intermediate portion of the backing layer 44 may remain uncoated to limit the adhesion of the backing layer 44 to the load 38, the contact layer 34 or other surfaces. Such an arrangement can facilitate the removal of the dressing 16 without redanifying the wound w.

Referring to Figures 2 and 3, a portal member 46 may be formed as a rigid component or, alternatively, portal member 46 may be molded of a polymeric material or flexible thermomeric elas20. The flexibility in the portal member 46 facilitates the placement of wound dressing 16 in the curved areas of a patient's skin. The portal member 46 includes a reservoir surface 54 and an ambient surface 56. The surface of the reservoir 54 is adapted to be positioned so that a primary opening 64 here can fluidly communicate with the vacuum reservoir 14, through a perforation 58, for example. The ambient surface 56 can be positioned in the dressing surrounding the environment 16 and includes an opening 68 adapted for connection to a suction device such as vacuum tube 24 of the vacuum system 12. A primary port 70 is defined between primary opening 64 and opening 68 to allow fluid communication between reservoir 14 and vacuum system 12.

The branch of primary port 70 is a radial row of supplementary ports 72 extending to reservoir surface 54. Each of the supplementary ports 72 ends at supplementary opening 74 distinct from and substantially spaced from primary opening 64. Any number, distribution and Supplementary door arrangement 72 can be included to distribute additional openings 74 along the reservoir surface 54. As Figure 2 illustrates, the supplementary openings 74 can be positioned close to a periphery of the reservoir surface 54 such that fluids can be drawn from reservoir 14 along a collection area that expands over the entire area covered by the limb portal number 46. Any number, size and arrangement of primary and supplementary openings 64, 74 are contemplated to effectively remove fluids for a particular application.

Referring next to Figure 4, wound dressing 16 can be installed on a patient to cover a wound w. Reservoir 14 is defined by or within wound dressing 16 when applied to the skin s. The contact layer 34 is positioned in direct contact with the wound w and the load 38 is positioned up to the level of healthy skin. The portal member 46 can be positioned over the connective region 50 of the support layer 44 in such a way that the primary and supplementary openings 64, 74 are aligned with the perforations 58. This will allow fluids to be drawn into the primary and supplementary ports 70 , 72 from reservoir 14. The ambient surface 56 is fluidly insulated from reservoir 14 except through the primary and supplementary ports 70, 72. Opening 68 in the ambient surface 56 receives the vacuum tube 24, thus fluidly connecting the vacuum system 12 with the reservoir 14.

The evacuation of the reservoir 14 can communicate a tendency for the loading material 38 and the wound exudate to migrate in the direction of the air flow. This migration trend can result in the obstruction or occlusion of one or more of the primary and supplementary doors 70, 72. However, since the portal member 46 can include many openings 64, 74 distributed throughout the entire area covered by the member of portal 46, the effectiveness of the VWT procedure may persist. If one of the openings 64 becomes clogged, fluids will be drawn into another of the openings 64, 74 which is distinct and substantially spaced from the clogged opening 64, 74.

Referring next to Figure 5, an alternate embodiment of a vacuum wound therapy system is represented by 10a. The wound dressing 16a includes a portal member 46a projecting through the entrance 50a of the covering layer 40a. The support layer 44a adheres to the flange 60a of the portal member 46a and also to the skin such that the reservoir surface 54a and ambient surface 56a are fluidly insulated except through the primary and supplementary ports 70a, 72a. The ambient surface 56a has an opening 68a here for connecting a suction device such as a vacuum tube 24. Fluid communication is thus established between reservoir 14a and vacuum system 12 through primary port 70a and primary opening 64a. Supplementary ports 72a establish fluid communication between primary port 70a and supplementary openings 74a in the reservoir surface 54a. In this arrangement, the reservoir surface 54a is enclosed by reservoir 14a.

The portal member 46a includes a radial row of supplementary doors 72a such that the openings 64a, 74a can be distributed substantially over the entire reservoir surface 54a. This arrangement provides a means of maintaining a portal 46a collection area exposed to dressing 16a as much as possible.

Although the above account has been described in more detail by way of illustration and example, for the sake of clarity or understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the attached claims.