AU755496B2

AU755496B2 - Surgical drape and suction head for wound treatment

Info

Publication number: AU755496B2
Application number: AU97360/01A
Authority: AU
Inventors: Keith Patrick Heaton; Kenneth William Hunt
Original assignee: KCI Medical Ltd
Current assignee: KCI Licensing Inc
Priority date: 1997-09-12
Filing date: 2001-12-21
Publication date: 2002-12-12
Anticipated expiration: 2018-09-09
Also published as: AU9736001A

Description

-1-

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant/s: Actual Inventor/s: Address for Service: KCI Medical Limited Keith Patrick Heaton and Kenneth William Hunt BALDWIN SHELSTON WATERS MARGARET STREET SYDNEY NSW 2000 3710000352 'SURGICAL DRAPE AND SUCTION HEAD FOR WOUND

TREATMENT'

CCN:

Invention Title: Details of Original Application No. 89934/98 dated 9 September 1998 The following statement is a full description of this invention, including the best method of performing it known to us:- File: 27471AUP01 la Surnicgl Drape and Suction Eaead for Wotud reeatment This invention rlatets to surgical drapes and suction heads for wound Surgical drape arm widely used in surgical operatious for the purpose of reducing infection. and filitating. the -handling of skin around incisions-. Norzaally, they are. tr Mpaet or KranslucenL Typically, they consist of a fienile, plastics film which is adhesive-coated and which -is, applied to the are of the -operation, pdort Making the icson- Surgical drapes aM also used for attaching tretment devices to Patients after an operation, such as catheters or drainage tubes.

A -find=,. recently developed use is for cozmecting a suction tube to a wound for the-pu rpose of stimulatiag healng ofthe wonur&L Such use is described in our earlier PCT Applications Nos. WO 96/05873 and WO 97/18007.

Vamius proposals have been, made in the past to design the surgical drape so tha~dt handlig of the sticky, flexibe plastics film is facilitedL For example, US Patent No. 5,437,622, describes a surgical- drape which is a laminat of three materials.

T~he fmz material comrsn a tranparent,- thin plastic film which is; adhesive-coated and this is protected with a laer of releae-coated paper. T-he other'face of theadhesive-coated film is strengthened" with a. reinforcing layer of a less flexible, plastics o fibL. Handling bars or- strip are attached to the flexibl, plastics film at its latra edges. to filitae handling of the flexible, plstics 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 treaftent, it is inconvenient for the surgeou or nurse to have to adapt a standard surgical drae for this purpose. It would be more convenient to have a surgical drape which was suitable without adaptation to accommuodate the treatment device.

-2- Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Accordingly, the invention provides a surgical drape which comprises a thin, flexible, adhesive-coated plastics film and a strengthening layer applied to the face opposite to the adhesive coating, the strengthening layer being a plastics film which is thicker or less flexible than said adhesive-coated film, and a protective, releasable layer 10 applied to the adhesive coating, the drape having an aperture through at least the strengthening film and adhesive-coated film to permit, in use, access to a wound area, at least one first edge of the drape having a non-adhesive coated handling bar for o separating the adhesive-coated film from the protective layer, and wherein the protective layer comprises a separate strip extending parallel to the first edge of the drape, and 15 which protects the adhesive coating in the region of the aperture and carries at least one flap overlapping the adjacent portion of the protective layer, said flap constituting a S• handle for facilitating removal of said strip prior to use.

Unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Preferably, non-adhesive-coated handling bars are positioned at opposite lateral edges of the drape.

In practice, surgical drapes may be manufactured by laminating an adhesivecoated flexible film, such as a polyurethane film, to a protective releasable layer, such as 2aa siliconised paper. A strengthening layer of thicker plastics material, e.g. a polyolefin such as polyethylene, may be applied to the non-adhesive coated face of the flexible film, so that a three-layer laminate is produced. These laminates are produced in substantial width and may be slit longitudinally to the desired width and then laterally to form drapes of the desired size.

After slitting to a desired width, handling bars are normally applied to the adhesive-coated layers at one or both lateral edges to facilitate separation of the film S* a -3from the protective, releasable layer. While an aperture could be cut at the desired position through the layers to accommodate a catheter or a device such as those described in our above-mentioned applications, it is difficult to handle the highly pliable and adhesive film after the releasable layer has been stripped off.

Although the strengthening layer does somewhat improve the handling characteristics, this is not a complete answer to the problem. However, the handling characteristics are substantially improved by providing a protective layer which is in at least two portions, one of which is in the form of a strip, e.g. one extending parallel to the lateral edges of the drape, and covering the peripheral area around the aperture 10 through the drape. By providing a flap on this portion of the releasable layer, it can be stripped off initially so that the drape is first positioned around the device which is to pass through the aperture, and then the remaining part of the protective releasable layer is stripped off to adhere the drape to the patient's skin around the area to be treated.

In a preferred form of the invention in which negative pressure therapy is applied 15 to a wound area, the surgical drape described above is combined with a suction head having a connector piece which is adapted to be connected to a suction tube. Thus, in •"this embodiment, the suction head can be adhered to the patient's skin in the area of the wound after removing the strip of protective releasable layer, and then the remaining part of the drape affixed to the patient's skin. In this way, the suction head is held firmly in place and, at the same time, seals the suction head to the wound area and prevents leakage of air from atmosphere into the wound area.

The invention also preferably includes a suction head having a design which facilitates the suction of fluid from a wound area.

According to a further preferred feature of the invention, therefore, there is provided a suction head for applying suction to a wound area which comprises a generally planar -4flange portion and a tubular connector piece on a first face, for connecting a suction tube to an aperture through the flange portion to'the other face, said other face having projections defining flow channels facilitating flow of fluid towards said aperture.

Preferably, the suction head described above is combined with a surgical drape, the drape comprising a thin, flexible, adhesive-coated plastics film, and the tubular connector piece extends through an opening in the plastics film with the adhesive coating adhered to said first face of the flange portion.

Preferably, the suction head is used in conjunction with an open-celled foam pad so that one surface of the foam pad is placed in contact with a wound area and the S 10 suction head applied to the other surface of the foam pad. In the case of deep wounds the foam may be shaped and placed so that it is packed into the wound cavity as described in our above cited PCT applications. According to another technique, which is particularly applicable to superficial wounds, the foam pad may be a relatively thin pad which is placed over the wound. The suction head is placed in contact with the open 15 face of the foam pad and the drape applied over the suction head to fix the assembly to the patient's skin.

Various types of open celled foams can be used as described in our above cited PCT applications. The foam may be a polyurethane foam but polyvinyl acetate (pva) foams are preferred, especially when used as a pad which is placed over the wound.

These are to some extent hydrophilic, which seems to exhibit beneficial comfort properties when applied to the skin. Wound healing is stimulated by maintenance of moist conditions in the wound area, and this is facilitated by using a hydrophilic foam.

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Referring to the accompanying drawings: Figure I represents a conventional design of sugical drape Figure 2 r epreents 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; Fe 4is aplan viwof the surldrape shnin igre 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 lxad shown in Figure 7 is a view simila to. Figure 6 but shows the suction bead secured to a skin surface with the drape and with a foam pad .located between the head and the skin Surface Fgur 8 is a perspective view of te drape. with a central strip portion of Ih protective sheet in the course of being remved, and.

IFgre 9(a)-9q(c) Mllstrae -the steps of affixing the dressing assmbly to a wound area on a patient's leg and attaChuIM to a negative pressure Lisanbly.

Refnin to Figures 1 and 2 of the accompanying drawings a conventional laminate for use as a surgical drape compie a thin, flexil transparent plastics fim I which is adhesive-coated oc one face 2, normally with a high-tack pressur-Sensitive adhesive, and is protected with a releasable layer 3. The thin plastics fim is conveniently of polyurethae because it transmits mnoisture. Layer 3 is normally considerably thicker than film I and is coated on the surfac adjacen to the adhesive with a releasable material such as a silicone to facilitate stripin away from the adhesive-coated film.

In order to facilitate remnoval of the adhecsive-coated film prior to use of the device, handling bars 4 arm bonded at each end to the adhecsive-coated film 1. Thus, by holding one of the bars 4, the protective layer, 3 can be stripped off and the adhesive face applie to the skin of the patient. To facilitate, handling of the thin, flexible film 1, a stentenn plastics film 5 is frequently applied to the frve faice of the plastics film 1. Thlis is generaly also tranisparent or translucent. Fitm 5 is preferably not bondied with adhesive to film I. but may. remain in contact by reason of electrostatic forces or because of close contact between the two conforming samfaces Of film I and film Usually, the surgeon or mirse will wish to strip off the protectie layer 5 after the film I has been correctlyplaced on the patient sin, and this can be facilitated by TMking partial, cuts 6 through the films I and S, so that as the handling bar 4 is drawn V. 0% 10 upward fiom the patient's skin, the adhesive film I remains adhered to the amt while the partial cuts 6 causes sep U.io of the flexible fim from the strengthening film S. Strengthening bars 7 may be provided to hold the lateral edges of the strengthenn film 5 and film I together with their main parts.

An alternative is shown in Figure 2, in which the strengthening film 5 is provided with a separate overlapping hanidlinig bar 14, to faciffitate its removal from the flexibl flm, 1.

Further details of the make-u and mamufacture of surgical drapes are given in US Patent No. 5,437,622 and European. Patent Application No. 0 161865 and the pr art referred to therein, the disclosure of which is. icorporated herein.

Rzecrring to Figure 3 and 4, the surgical drape of this invention compriss a protective outer film 20, laminated to a thin, flexible ffim 21. The flexible film 21 includes an adhe~sive-coated layer which is protected with a release-coated sheet mateial24.Lateral edges of the flexible film 21 are provided with handling bars 23.

Thus the design is essentially the same as that shown in Figues I and 2.

The drape -of the present invention differ from the drape shown in Figures I and 2 in that an aperture 25 is cut through the strengthening layer .20 and through the flexible- layer 21.- The other difference conmared with the prior art drapes is ta the Orotective releasable layer is formed in at least two sections.

In the embodiments shown in Figume 3 and 4, the 'central portion of the releasable layer comprises a strip 26, having flps 27 which overlap the remaining outboard portions 'of the relcasable layer. The Purpose of this is to enable the central strip 26 to be removed fixsi, 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 *4 10 patient's skin with the peripheral areasof eposedI adhtsive-coated film.

An example of a device for applying suction to the wound area is illustrated in Figures 5, 6 and 7.

Referring to these. Figures, the suction bead comprises a flainge portioA .:geerally 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 apcrture 34, having a tubular end 36 adapted for receivig 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 substantiallfy smooth surface.

-8- In use, the connector portioL .35 is sized so that it extends, throvh the aperture in the surgical drape shown in Figures 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. T1he suction head can then 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 p atien. The flange 30 of the suction head may be somewhat oval as shown in Figure 5, and have dimensions as indicated in this Figure, iLe. a longer dimension of about 95mm and a short dimension of about Ailetuatively, th fange a. may be circular an b ac in planvie. F'or exmpe thediaer of acirclar suction ead =y be from abot.30to e-g. about 40mm. It his been, found that the suction head flange should not overlap the area of the wound. Thzs, in the case of smaller wounds a smalle suction head is indicated..

Figure 7 shows the suction head attached to. a wound. area 71 of a patient 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 suctioxi head and :fbam pad are pressed into contact with the wound 'ame by a surgical. drape 20 baying, an adhesive surface 74. The'adhesive suiface is bonded to the patint's sin 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 cathetier tubes being- finted -to the connector 35, the latter may have a cusoiiused cross-section or internal projection such as a rib or .key which co-operates with ~u corresponding slot or key way in the cadmur- Altrnatively, the catheser many -9be moulded with a projection or longitudinal rib which co-operates with a corresponding slot or key way in the aperture of the connector 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 illustrate the way in which the drape/suction head combination is fitted to a wound on a patient's skin. In Figure 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 10 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 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 **see* apply negative pressure to the wound. The suction head and drape assembly is shown in Figure 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.

Although the invention has been described with reference to specific examples it will be appreciated to those skilled in the art that the invention may be embodied in many other forms.

Claims

1. A surgical drape which comprises a thin, flexible, adhesive-coated plastics film and a strengthening layer applied to the face opposite to the adhesive coating, the strengthening layer being a plastics film which is thicker or less flexible than said adhesive-coated film, and a protective, releasable layer applied to the adhesive coating, the drape having an aperture through at least the strengthening film and adhesive-coated film to permit, in use, access to a wound area, at least one first edge of the drape having a non-adhesive coated handling bar for separating the adhesive-coated film from the 10 protective layer, and wherein the protective layer comprises a separate strip extending V099C O parallel to the first edge of the drape, and which protects the adhesive coating in the 000 region of the aperture and carries at least one flap overlapping the adjacent portion of the protective layer, said flap constituting a handle for facilitating removal of said strip prior to use. 15

2. A surgical drape substantially as herein described with reference to any one of •the embodiments of the invention illustrated in the accompanying drawings. DATED this 21st Day of December, 2001 0 S* KCI MEDICAL LIMITED Attorney: STUART M. SMITH Fellow Institute of Patent Attorneys of Australia of BALDWIN SHELSTON WATERS