This invention relates to surgical drapes for wound treatment.
Surgical drapes are widely used in surgical operations for the purpose of reducing infection and facilitating the handling of skin around incisions. Normally, they are transparent or translucent, Typically, they consist of a flexible plastics film which is adhesive-coated and which is applied to the area of the operation, prior to making the incision. Surgical drapes are also used for attaching treatment devices to patients after an operation, such as catheters or drainage tubes.
A further, recently developed use is for connecting a suction tube to a wound for the purpose of simulating healing of the wound. Such use is described in our earlier
PCT Applications Nos. WO 96/05873 and
WO 97/18007.
EP0177632 discloses an adhesive film dressing for medical and surgical applications for use as wound coverings and to secure IV catheters.
US4,605,399 discloses a transdermal infusion device for introducing drugs and the like into the human body through the skin.
US5,437,651 discloses a medical suction apparatus for absorbing an collecting blood and other fluids which accumulate in a patent during a surgical procedure.
US5,636,643 discloses a wound treatment apparatus which utilises negative pressure. The two-part form of independent claim 1 is based on this document.
EP 0 619 105 discloses a wound treatment apparatus which also utilises negative pressure and further incorporates an absorbent layer.
US5,437,622 discloses a transparent adhesive dressing of synthetic material.
Various proposals have been made in the past to design the surgical drape so that handling of the sticky, flexible, plastics film is facilitated. For example,
US Patent No. 5,437,622, describes a surgical drape which is a laminate of three materials. The first material comprising a transparent, thin plastics film which is adhesive-coated and this is protected with a layer of release-coated paper. The other face of the adhesive-coated film is strengthened with a reinforcing layer of a less flexible plastics film. Handling bars or strips are attached to the flexible plastics film at its lateral edges to facilitate handling of the flexible plastics film after stripping away the protective releasable layer.
Where it is desired to use a surgical drape primarily to attach a device such as a catheter to a wound area after an operation or for long term treatment, it is inconvenient for the surgeon or nurse to have to adapt a standard surgical drape for this purpose. It would be more convenient to have a surgical drape which was suitable without adaptation to accommodate the treatment device.
One aspect of the present invention is directed to a solution to this problem.
There is provided a device for transmitting negative pressure to a wound area, said device comprising a wound cover comprising a flexible drape with an aperture there through and an outward surface opposite an inward surface, the inward surface being coated with an adhesive and being intended to face a patient's body in use; a suction head comprising a substantially planar flange portion defining an inward surface intended to face a patient's body in use and an opposite outward substantially smooth surface, and a tube connector in liquid tight-joinder with said drape , said tube connector having an opening adapted to connect to a tube in which negative pressure may be produced, said opening being in fluid communication with the inward surface of said drape through the aperture ; wherein the adhesive inward surface of the flexible drape is bonded to the smooth surface of the flange; further comprising a foam pad appropriately shaped to cover the flange portion and to be positioned in use over a wound and adjacent the inward surface of the flange portion of the suction head, and in that the inward adhesive surface of the flexible drape is shaped to enable the drape to simultaneously adhere to the foam pad , the outward surface of the flange portion and to a patient's body around the foam pad , and in that the device further comprises a backing sheet having a release coated surface and adhered to a central strip of the drape inward surface and covering the suction head, and lateral protective strips (104, 105) adhered to lateral strips of the drape inward surface to which the backing sheet is not adhered.
A selection of optional features of the invention are described in the dependent claims.
Further features and advantages of the present invention will be apparent from the following description and accompanying drawings, of non-limiting examples in accordance with the invention.
Referring to the accompanying drawings:-
- Figure 1 represents a conventional design of surgical drape;
- Figure 2 represents a variation in the design of the handling bars at one end of the drape shown in Figure 1;
- Figure 3 is a view similar to Figure 1 of a surgical drape in accordance with the invention;
- Figure 4 is a plan view of the surgical drape shown in Figure 3;
- Figure 5 is a plan view from beneath of a suction head in accordance with the invention; and
- Figure 6 is a side elevation of the suction head shown in Figure 5;
- Figure 7 is a view similar to Figure 6 but shows the suction head secured to a skin surface with the drape and with a foam pad located between the head and the skin surface;
- Figure 8 is a perspective view of the drape with a central strip portion of the protective sheet in the course of being removed, and
- Figures 9(a)~9(c) illustrate the steps of affixing the dressing assembly to a wound area on a patient's leg and attachment to a negative pressure assembly.
Referring toFigures 1 and 2 of the accompanying drawings, a conventional laminate for use as a surgical drape comprises a thin, flexible, transparent plastics film 1 which is adhesive-coated on one face 2, normally with a high-tack pressure-sensitive adhesive, and is protected with a releasable layer 3. The thin plastics film is conveniently of polyurethane because it transmit moisture. Layer 3 is normally considerably thicker than film 1 and is coated on the surface adjacent to the adhesive with a releasable material such as a silicone to facilitate stripping away from the adhesive-coated film.
In order to facilitate removal of the adhesive-coated film prior to use of the device, handling bars 4 are bonded at each end to the adhesive-coated film 1. Thus, by holding one of the bars 4, the protective layer 3 can be stripped off and the adhesive face applied to the skin of the patient. To facilitate handling of the thin, flexible film 1, a strengthening plastics film 5 is frequently applied to the free face of the plastics film 1. This is generally also transparent or translucent. Film 5 is preferably not bonded with adhesive to film 1, but may remain in contact by reason of electrostatic forces or because of close contact between the two conforming surfaces of film 1 and film 5.
Usually, the surgeon or nurse will wish to strip off the protective layer 5 after the film 1 has been correctly placed on the patient's skin, and this can be facilitated by making partial cuts 6 through the films 1 and 5, so that as the handling bar 4 is drawn upwards from the patient's skin, the adhesive film 1 remains adhered to the patient, while the partial cuts 6 causes separation of the flexible film from the strengthening film 5. Strengthening bars 7 may be provided to hold the lateral edges of the strengthening film 5 and film 1 together with their main parts.
An alternative arrangement is shown inFigure 2, in which the strengthening film 5 is provided with a separate overlapping handling bar 14, to facilitate its removal from the flexible film 1.
Further details of the make-up and manufacture of surgical drapes are given in
US Patent No. 5,437,622 and European Patent Application No.
0161865 and the prior art referred to therein.
Referring toFigures 3 and 4, the surgical drape of this invention comprises a protective outer film 20, laminated to a thin, flexible film 21. The flexible film 21 includes an adhesive-coated layer which is protected with a release-coated sheet material 24. Lateral edges of the flexible film 21 are provided with handling bars 23. Thus far, the design is essentially the same as that shown inFigures 1 and 2.
The drape of the present invention differs from the drape shown inFigures 1 and 2 in that an aperture 25 is cut through the strengthening layer 20 and through the flexible layer 21. The other difference compared with the prior art drapes is that the protective releasable layer is formed in at least two sections.
In the embodiments shown inFigures 3 and 4, the central portion of the releasable layer comprises a strip 26, having flaps 27 which overlap the remaining outboard portions of the releasable layer. The purpose of this is to enable the central strip 26 to be removed first, without disturbing the remaining portions of the releasable layer. The drape can then be fitted around the wound area and, if desired, a suction device or other treatment device passed through the aperture 25 and secured to the patient's skin with the peripheral areas of exposed adhesive-coated firm,
An example of a device for applying suction to the wound area is illustrated inFigures 5, 6 and7.
Referring to these Figures, the suction head comprises a flange portion 30 halving a tapered edge 31, and a profile which may be of any desired shape but is generally rounded at its edges. On the face of the flange 30 intended for contact with the patient's skin or a foam pad are formed a series of projections 32 which are distributed over the surface of the flange apart from the peripheral edge portion 31. The purpose of these projections is to provide fluid channels 33 facilitating the flow of fluids from any point of the flange to a central point 34, from which it is intended to apply suction. The suction head includes a connector 35, located above the aperture 34, having a tubular end 36 adapted for receiving and connecting a catheter. The tubular end may have an outwardly tapered portion to facilitate feeding a catheter into the connector. The upper surface 37 of the suction head has a substantially smooth surface.
In use, the connector portion 35 is sized so that it extends through the aperture 25 in the surgical drape shown inFigures 3 and 4, with the adhesive surface around the aperture bonded to the smooth surface 37 of the flange 30. The suction head may be packaged in this condition with the surgical drape so that in use, the strip 26 is removed by pulling on the handles 27 thus exposing the adhesive surface in the vicinity of and surrounding the suction head. The suction head can then be fixed in the desired position on the patient's wound and then the remaining portion of the protective film removed to fix the drape to the patient. The flange 30 of the suction head may be somewhat oval as shown inFigure 5, and have dimensions as indicated in this Figure, i.e. a longer dimension of about 95mm and a short dimension of about 70mm. Alternatively, the flange may be circular and be smaller in plan view. For example, the diameter of a circular suction head may be from about 30 to 50mm in diameter, e.g. about 40mm. It has been found that the suction head flange should not overlap the area of the wound. Thus, in the case of smaller wounds a smaller suction head is indicated.
Figure 7 shows the suction head attached to a wound area 71 of a patient 70. The suction head is pressed into firm contact with a flexible, open-celled foam 73, which is itself pressed into contact with the wound area 71. The suction head and foam pad are pressed into contact with the wound area by a surgical drape 20 having an adhesive surface 74. The adhesive surface is bonded to the patient's skin outside the periphery of the foam pad and suction head. It is also bonded to upper surface 37 of the suction head. An aperture is formed in the drape to permit the connector portion 35 to extend upwardly through the drape. In order to avert the danger of incorrect catheter tubes being fitted to the connector 35, the latter may have a customised cross-section or internal projection such as a rib or key which co-operates with a corresponding slot or key way in the catheter. Alternatively, the catheter may be moulded with a projection or longitudinal rib which co-operates with a corresponding slot or key way in the aperture of the connector 35.
The foam pad may be packaged in a plastic pouch, sterilised by gamma irradiation and supplied in the same box or in other packing units as the suction head and drape.
Figures 8 and 9(a)∼(b) illustrate the way in which the drape/suction head combination is fitted to a wound on a patient's skin. InFigure 8, a backing sheet 101 having a release coated surface is removed in the first step from the adhesive face 102 of the drape to expose the face of the connector 30. A pad 103 of foam is positioned over the wound area and the drape placed over the foam pad, the drape being adhered to the skin above and below the pad (Figure 9a). The lateral protective strips 104 and 105 are removed in turn from the drape and the assembly adhered to the skin (Figures 9(b) and 9(c). Finally, the spout 36 is connected to a tube 106 which is then connected to a source of suction, e.g. a pump as described in our above PCT application, in order to apply negative pressure to the wound. The suction head and drape assembly is shown inFigure 8, with the smooth surface 37 adhered to the drape, is conveniently packaged in an easily openable plastic bag or pouch, and sterilised for immediate use.