HK1165981B - Film for covering a wound - Google Patents

Description

Film for covering wounds

The invention relates to a wound dressing comprising a first strip-like element forming a first boundary surface and a second strip-like element connected to the first strip-like element forming a second boundary surface facing away from the first boundary surface and substantially parallel thereto. The invention also relates to a wound first aid kit comprising such a wound dressing and to a method for producing a wound dressing according to the invention.

Such wound dressings are used in different conditions or wounds, especially in the open abdominal region, if the exposed wound or the open abdomen has to be temporarily bandaged. If a plurality of operations are to be performed daily, in order to ensure a rapid access to the internal organs on the one hand and to reduce the adverse effects of exudates caused by inflammation in the wound area on the other hand. Mortality in some indication cases can be significantly reduced by temporary bandaging coverage.

From a medical point of view, there are in principle two main requirements for use as a wound dressing suitable for the above-mentioned purposes of use. On the one hand, the problem of exudate in the wound area must be successfully dealt with, in particular in the case of an open abdomen, that is to say the exudate is sucked off over the entire wound area or over the entire wound area. In addition, while isolating the wound from the surrounding environment, friction between the organs and the peritoneum and wound dressing is reduced. It must also be ensured that the wound dressing does not allow impurities to enter the open wound or the open wound area.

EP 0261167B 1 discloses a liquid permeable wound dressing in direct contact with the wound, which has a hydrophobic layer to prevent the wound dressing from adhering to the wound area and thereby soiling the wound. The wound dressing disclosed in this document is not satisfactory in dealing with exudate problems in the wound area.

In order to improve the treatment of exudate in the wound area, US 7,381, 859B 2 proposes a wound dressing in which a foam-like interlayer is arranged between two liquid-permeable, film-like strip-like elements (which can be made of plastic film) which can absorb exudate. However, the wound dressing disclosed in the above-mentioned document has a problem that the absorption of exudate in the border area of the wound dressing is not satisfactory, and thus complications may occur in the border area in the wound treatment.

In WO 2007/118652 a1 a protective dressing is disclosed, on which a liquid-absorbent, non-adhesive secondary bandage can be applied, which is provided with a plurality of three-dimensional holes in order to form a first smooth surface and a second surface with a rough feel. In the use of this known wound dressing, the absorbent body attached thereto is exchangeable in order to ensure satisfactory wound treatment over a longer period of time. However, when the wound dressing systems disclosed in the above documents are used, exudate management in the whole wound area, in particular in the abdominal area, is not satisfactory;

DE 102008034362 a1 describes a wound care pack for absorbing wound liquids, having a material portion made of a highly hydropolymer absorbent material, and at least one layer permeable to fluids, which is located directly on the flat material portion and allows the formation of channels for liquid substances exuding from the wound into the material portion made of absorbent material;

DE 102006017194 a1 discloses the use of a flexible material part which is permeable to fluids and made of thermoplastic, having a first smooth surface, a second surface facing away from the first smooth surface, and a plurality of three-dimensional perforations, the walls of which extend from the first smooth surface and which terminate in respective flanges having free ends, so that the second surface is provided with a rough grip, so that as a primary sterile dressing it can be used as a wound cover, over which a secondary absorbent dressing can be placed, and adherence of exudate is avoided;

DE 202006015547U 1 discloses a supporting compression element comprising a fleece mat with superabsorbent particles, to which at least one foam mat is provided;

DE 102007049428 a1 relates to a wound care package with a layer comprising a superabsorbent polymer and a layer comprising a flexible foam;

US 2004/030304 a1 describes a system and method for temporary treatment of wounds, particularly abdominal wounds, by which the wound treatment process will be facilitated, with absorbent sites being provided on the upper peripheral edge of the foam layer to apply negative pressure to the wound.

In view of the foregoing problems of the prior art, it is an object of the present invention to provide a wound dressing by which exudate can be effectively treated over the entire wound area without contaminating the wound.

According to the invention, the above-mentioned object is achieved by an improvement of the known wound dressing, which is characterized in that at least one drainage space is formed between a first inner boundary surface of the first strip-like element facing away from the first boundary surface and a second inner boundary surface of the second strip-like element facing away from the second boundary surface, the depth of which in a depth direction perpendicular to the boundary surfaces ensures a capillary action on body fluids, in particular exudates, contained in the drainage space.

In the wound dressing according to the invention, a capillary action between the strip-like elements is achieved by the formation of the drainage space, by which capillary action it is possible on the one hand to prevent body fluid, in particular exudate, from flowing out of the drainage space and on the other hand to spread the body fluid over the entire discharge surface, so that no further supplementary measures, such as the addition of an absorbent body, are necessary. In this way, exudate can be treated effectively over the entire wound area, since there is no need to keep an edge region without capillary function that affects exudate treatment. The wound dressing according to the invention can be easily tailored to the size or configuration of the wound, in particular of the abdominal space, and ensures that the desired drainage function is achieved over the entire wound dressing surface. Here, the wound dressing may also have a smooth surface which prevents the tissue and cells of the wound or the surrounding organs from adhering. When using a wound dressing according to the invention, the entry of body fluids into the drainage space can be ensured in that the band element itself is made of a material through which liquids can pass.

According to the invention, it is particularly advantageous if at least one of the band elements has an opening which allows body fluid to enter the drainage space. The stability of the overall structure of the wound dressing according to the invention is improved if the at least one opening is formed by a channel which extends from one strip-like element and towards the inner boundary surface of the other strip-like element lying opposite it and opens into the drainage space, while the channel wall is preferably formed integrally with the strip-like element, particularly preferably if the channel is formed by a hole in the strip-like element.

In the embodiment of the invention described above, the treatment of the exudate is effectively improved if the cross-section of the channel in a plane perpendicular to the depth direction, in particular in order to obtain a capillary action that promotes the entry of body fluid into the drainage space, becomes smaller starting from the band element in the direction towards the inner boundary surface opposite thereto. In this way, on the one hand, drainage of exudate from the wound area is facilitated and, on the other hand, it is prevented from flowing back into the wound from the drainage space.

In a wound dressing according to the invention, it is possible to ensure both an effective drainage of exudate and a good overall stability of the wound dressing if at least one of the strip-like elements has a plurality of openings, preferably arranged in a grid, in particular in a rectangular grid, wherein the distance between adjacent openings or grid points is 15 mm or less, preferably 5 mm or less, most preferably 3 mm or less.

In terms of the overall stability that is desired to be achieved, a wound dressing according to the invention proves to be suitable if, in a projection plane in the depth direction, the open access openings on the strip-like element are arranged between the open access openings on the other strip-like element.

The arrangement of the openings in the wound dressing according to the invention is particularly advantageous in the case of openings formed by channels, in particular when the wound dressing is used in combination with a source of underpressure which is used for sucking exudate from the wound area, in particular the abdominal space, in order to avoid collapse of the overall structure in case of underpressure. It is particularly advantageous in this connection if the at least one channel forming the opening in the band element covers more than 50% of the entire depth of the drainage space in the depth direction.

In order to ensure the required penetration of the band element, the area of the access opening of each opening facing the drainage space in a plane perpendicular to the depth direction is 0.1 mm²Or greater, preferably 0.5 mm²Or more, particularly preferably 1 mm²Or larger. If the area of the opening is 5 mm²Or less, preferably 4 mm²Or less, particularly preferably 3 mm²Or smaller, the desired capillary action can be achieved while avoiding liquid from flowing back from the drainage space to the wound area.

As mentioned before, the channel forming the opening in the strip-like element may be formed by a hole in the strip-like element. In this connection, in order to obtain a smooth surface, which effectively prevents the adhesion of cells at the tissue or at the wound or in the surrounding organs, the channel walls are at least partially curved in a section parallel to the depth direction and smoothly merge into the boundary surfaces of the strip-like elements. The connection of the strip-like elements is effected by fixing regions which are arranged in a punctiform and preferably grid-like manner, while ensuring a drainage space which functions as a drain. Here, the fixing may be accomplished by welding, gluing or other fastening means. But this connection should not impede but support the drainage of exudates. In this connection, it is advantageous if the area of the fixing regions in a cross section perpendicular to the depth direction is 5 mm²Or less, preferably 3 mm²Or less, particularly preferably 2 mm²Or less, wherein the distance between the grid points of the respective fixed areas or of the fixed areas arranged in the form of a grid is 2 mm or more, preferably 3 mm or more, particularly preferably 5 mm or more.

Whether the fixing is effected by welding, gluing or by other connecting means, material bridges (materialbrucke) can be formed in the fixing region which connect the inner boundary surfaces of the strip elements to one another. In the wound dressing according to the invention, the distance between the inner boundary surfaces of the strip-like elements is 5 mm or less, preferably 4 mm or less, particularly preferably 2 mm or less, in order to achieve the desired capillary action in the drainage space. Here, it is ensured by capillary action in the drainage space that exudate is spread over the entire area of the wound dressing if the distance between the inner boundary faces of the strip-like elements is 0.05 mm or more, preferably 0.1 mm or more, particularly preferably 0.3 mm or more.

In the wound dressing according to the invention, at least one of the strip-like elements can have a preferably perforated plastic film, it being particularly preferred if the strip-like element is formed entirely from a perforated plastic film.

It is particularly advantageous that a wound dressing according to the invention can be used in combination with negative wound pressure therapy. Here, the wound dressing according to the invention acts as a bandage or as an interface between the wound (tissue, cells) and the wound filler or exudation exudate area. It is particularly advantageous that the wound dressing according to the invention is suitable for use on wounds in an open abdominal cavity. Here, the wound dressing according to the present invention is placed on an organ (viscera) in the entire abdominal space, and the wound dressing performs a drainage function and has a very smooth surface, thereby preventing adhesion or friction of tissues and films. The wound dressing according to the invention can be pre-shaped anatomically or be tailored to the specific situation. In combination with negative pressure therapy, a wound dressing according to the invention may be provided with a filling medium, such as gauze or foam, which covers up to the edges of the skin. A wound drainage element, which is optionally tubular, can be inserted into the wound filler. Hoses for drainage of exudates or wounds are led out from the abdominal space and connected to a source of negative pressure, which can be secured by a pump or a central pressure system in the hospital. Finally, the wound is tightly sealed by an adhesive film. The negative pressure source can drain the exudates from the whole abdominal cavity by means of the wound dressing according to the invention, so that the exudates can be effectively treated. The film for tightly sealing the wound seals the internal organs from the outside and controls humidity and temperature. In addition, it also blocks the entry of bacteria, viruses and microorganisms, as does the skin.

As mentioned above, a wound first aid kit according to the invention comprises a wound dressing according to the invention, a liquid absorbent material such as foam or gauze which can be arranged on the dressing, a tightly sealable film and, if desired, a tubular drainage element which can be connected to a source of negative pressure.

A method for manufacturing a wound dressing according to the invention is characterized in that a strip-shaped material is punched, for example by punching, to form funnel-shaped openings, and the two punched sections of the strip-shaped material are placed on top of each other with opposite funnel-shaped openings and are then connected to each other, for example by spot welding. In this method, the required spacing between the inner boundary surfaces can be ensured by the depth of the funnel-shaped opening. However, the precision of the perforation process is limited in this case, so that some funnel openings can be applied to the inner boundary surface of the opposite band element, while other funnel openings open into the drainage space.

In order to avoid adhesion phenomena in a wound dressing according to the invention, the at least one strip-like element may be hydrophilic or hydrophobic. Furthermore, it is also conceivable to add a layer of expandable material.

In the drainage space, an absorbent medium, for example foam, gauze or an open-cell material, can be arranged, in particular padded, between the strip elements. It is also within the scope of the invention to include a super absorbent or other storage material between the ribbon elements.

All the important details of the invention, which are not described in detail in the preceding description, are explained below with reference to the drawings. Wherein the drawings comprise:

FIG. 1 shows a schematic view of a wound dressing according to the invention, an

Fig. 2 shows an embodiment of a wound first aid kit according to the invention.

The wound dressing shown in fig. 1 comprises a first strip-like element 10 having an outer boundary surface 12 and a second strip-like element 20 having an outer boundary surface 22. A drainage space 40 is formed between the inner boundary surface 14 of the first band element 10 facing the second band element 20 and the inner boundary surface 24 of the second band element 20 facing the first band element 10. In the embodiment of the invention shown in the figures, the drainage space 40 has a depth T in the direction perpendicular to the main faces of the strip-like elements 10 and 20 of between 0.1 and 4 mm.

The first band element 10 has a plurality of channel-like holes 16 arranged in a grid-like manner. The wall of the channel 16 is curved in a section parallel to the depth direction and smoothly transitions into the outer boundary surface 12 of the first band element 10. Likewise, the second band element 20 has a plurality of likewise channel-shaped openings 26 arranged in a grid-like manner. The channels 16 and 26 each cover more than half of the entire depth of the drainage space 40. Here, the channels 16 and 26 are arranged such that a projection of the channel access of the channel 16 in the depth direction falls between the channel accesses of the channel 26.

In the embodiment of the invention shown in the figures, the diameter of the tapered channel 16 or 26 in the region of the access opening is 0.2 to 1 mm. The strip-like elements 10 and 20 are connected to each other by material bridges 30 arranged in a grid-like manner. The distance between the inner boundary surfaces 14 and 24 is ensured by a material bridge 30. The attachment region 30 may be achieved by welding, adhesive bonding or other fastening means. The band elements 10 and 20 can be realized in the form of plastic films. Here, synthetic plastics such as PE, PP, PET, Polyurethane (PUR), teflon (PTFE) may be used, or films based on biodegradable plastics or renewable plastics such as poly β -hydroxybutyrate (PHB), Polylactide (PLA), polylactic acid, cellulose (CMC) -based raw materials, etc. may be used. The structure of the ribbon-like element with holes can be realized by a manufacturing process of non-woven fabric. Here, in order to manufacture a nonwoven fabric or a woven fabric, synthetic fibers may be used, and natural fibers (e.g., silk, cotton), as well as inorganic fibers (glass ceramic …) or metals (silver fibers) may be used. Within the framework of the invention, it is also conceivable to add an antibacterial or bacteriostatic layer to the strip-like elements 10, 20 or to the drainage space 40. The antibacterial or bacteriostatic effect can be achieved by, for example, PHMB, silver, chlorhexidine, etc.

According to the embodiment shown in fig. 2, the wound dressing 2 is placed on the wound and then the wound is covered with a filler 100, such as foam, gauze or the like, and covered with a sealing film 50. The exudate conduit 6 passes through the sealing membrane 50 and may be connected to a source of negative pressure to draw exudate away from the wound space.

As mentioned before, the following advantages are obtained in the use of a wound dressing according to the invention:

the holes have an inwardly protruding structure, supporting the drainage of exudate and preventing the exudate from flowing back into the wound space (capillary action);

the open drainage chamber provides capillary action to the drainage layer 40, thereby preventing the wound dressing from draining away;

a smooth surface is obtained by a smooth transition between the passage 16 or 26 and the boundary surface 12 or 24 of the strip-like element, so that adhesion of tissue or cells of the wound or of surrounding organs is prevented;

the combination of pore size and film smoothness prevents tissue ingrowth or adhesion;

the drainage space 40 always provides an open space for the discharge of exudates;

the wound dressing can be tailored to the size or configuration of the wound or abdominal cavity without affecting the drainage function.

Finally, it is pointed out that in the embodiment shown in the figures, the distance between the central axes of the channels 16 and 26, which are indicated by a and b in fig. 1, is at least 0.1 mm and at most 4 mm.

The invention is not limited to the embodiments shown in the drawings. Rather, the wound dressing can also have other forms of openings and/or a multilayer structure for forming two, three or more drainage spaces one above the other. In this case, at least in the case of the inner band element, the boundary surface of the band element facing away from the inner boundary surface does not form an outer boundary surface.

Claims (35)

1. Wound dressing comprising a first strip-like element (10) and a second strip-like element (20) connected to the first strip-like element (10), the first strip-like element (10) forming a first boundary surface (12) and the second strip-like element (20) forming a second boundary surface (22) facing away from the first boundary surface (12) and being substantially parallel to the first boundary surface (12), characterized in that at least one drainage space (40) is formed between a first inner boundary surface (14) on the first strip-like element (10) facing away from the first boundary surface (12) and a second inner boundary surface (24) on the second strip-like element (20) facing away from the second boundary surface (22), the at least one drainage space (40) having a depth (T) in a depth direction perpendicular to the boundary surfaces (12, 22) of 5 mm or less, capillary action on the body fluid contained in the drainage space (40) is ensured.

2. A wound dressing according to claim 1, wherein the depth (T) is 4 mm or less.

3. A wound dressing according to claim 2, wherein the depth (T) is 2 mm or less.

4. The wound dressing of claim 1, wherein the bodily fluid is exudate.

5. Wound dressing according to claim 1, characterized in that at least one of the strip-like elements (10, 20) is provided with an opening allowing bodily fluids to enter the drainage space (40).

6. Wound dressing according to claim 5, characterized in that at least one opening is formed by a channel (16, 26) which starts from one strip-like element (10, 20) and extends towards the inner boundary surface (14, 24) of the other strip-like element (10, 20) opposite thereto and which opens into the drainage space (40), while the channel wall is formed in one piece with the strip-like element (10, 20).

7. The wound dressing according to claim 6, characterized in that the channels are formed by holes of the strip-like elements (10, 20).

8. Wound dressing according to claim 6, characterized in that the cross-section of the channels (16, 26) in a plane perpendicular to the depth direction decreases from the strip-like element (10, 20) in the direction towards the boundary surface (14, 24) opposite thereto in order to obtain a capillary action for promoting the entry of body fluid into the drainage space (40).

9. A wound dressing according to any one of claims 5 to 8, characterized in that at least one strip-like element (10, 20) has a plurality of openings arranged in a grid-like manner, wherein the distance between adjacent openings is 15 mm or less.

10. A wound dressing according to claim 9, wherein the distance between adjacent openings is 5 mm or less.

11. A wound dressing according to claim 10, wherein the distance between adjacent openings is 3 mm or less.

12. The wound dressing according to any one of claims 5 to 8, characterized in that in one projection plane in the depth direction, the open access openings arranged on the strip-like elements (10, 20) are located between the open access openings on the other strip-like element (10, 20).

13. A wound dressing according to any one of claims 6 to 8, characterized in that at least one channel (16, 26) covers more than 50% of the entire depth (T) of the drainage space (40) in the depth direction.

14. A wound dressing according to any one of claims 5 to 8, characterized in that the access area of each opening facing the drainage space (40) in a plane perpendicular to the depth direction is 0.1 mm²Or larger.

15. The wound dressing of claim 14, wherein the access area is 0.5 mm²Or larger.

16. The wound dressing of claim 15, wherein the access area is 1 mm²Or larger.

17. A wound dressing according to any one of claims 5 to 8, characterized in that the access area of each opening facing the drainage space (40) in a plane perpendicular to the depth direction is 50 mm²Or smaller.

18. The wound dressing of claim 17, wherein the access area is 5 mm²Or smaller.

19. The wound dressing of claim 18, wherein the access area is 4 mm²Or smaller.

20. The wound dressing of claim 19, wherein the access area is 3 mm²Or smaller.

21. A wound dressing according to any of claims 6 to 8, characterized in that the channel walls are at least partly curved and smoothly transition into the boundary surfaces (12, 22) of the strip-like elements in a cross section parallel to the depth direction.

22. A wound dressing according to any one of the preceding claims 1 to 8, characterized in that the strip-like elements (10, 20) are interconnected by fixing areas (30) which are point-like and arranged in a grid-like manner.

23. A wound dressing according to claim 22, wherein each securing region(30) An area in a cross section perpendicular to the depth direction of 5 mm²Or smaller.

24. A wound dressing according to claim 23, characterized in that the area of each fixing area (30) in a cross-section perpendicular to the depth direction is 3 mm²Or smaller.

25. A wound dressing according to claim 24, characterized in that the area of each fixing area (30) in a cross-section perpendicular to the depth direction is 2 mm²Or smaller.

26. Wound dressing according to claim 22, characterized in that a material bridge is formed in the fixing zone (30) which connects the inner boundary faces (14, 24) of the strip-like elements (10, 20) to one another.

27. A wound dressing according to any of the preceding claims 1 to 8, characterized in that the distance between the inner boundary surfaces (14, 24) is 0.05 mm or more.

28. A wound dressing according to claim 27, wherein the distance between the inner boundary surfaces (14, 24) is 0.1 mm or more.

29. A wound dressing according to claim 28, wherein the distance between the inner boundary surfaces (14, 24) is 0.3 mm or more.

30. A wound dressing according to any of the preceding claims 1 to 8, characterized in that at least one strip-like element (10, 20) has a plastic film with holes.

31. A wound dressing according to any one of the preceding claims 1 to 8, characterized in that at least one strip-like element (10, 20) is provided with a layer of antibacterial or bacteriostatic material on the surface.

32. A wound dressing according to claim 31, wherein the antibacterial or bacteriostatic material is PHMB, silver, or chlorhexidine.

33. A wound dressing according to any of the preceding claims 1 to 8, characterized in that at least one of the strip-like elements is provided with means for preventing adhesion phenomena, said means being made of a hydrophilic or hydrophobic material or being provided with a layer of a swellable material.

34. A wound first aid kit comprising a wound dressing according to any of the preceding claims 1 to 33, further comprising a liquid absorbent arranged on the wound dressing, and a tightly sealable film.

35. Method for manufacturing a wound dressing according to any of the preceding claims 1-33, characterized in that the strip-shaped material is punched with a funnel-shaped opening, and the two punched sections of the strip-shaped material are placed on top of each other with opposite funnel-shaped openings and then joined to each other by spot welding.