GB2558942A

GB2558942A - Layered hydrogel surgical dressing

Info

Publication number: GB2558942A
Application number: GB1701086.9A
Authority: GB
Inventors: Roger Deas Alexander; Teoman Naskali Ahmed; Sirtmac Soner
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-01-23
Filing date: 2017-01-23
Publication date: 2018-07-25
Also published as: GB201701086D0

Abstract

A layered dressing has a sponge outer layer 1 saturated with an anti microbial hydrogel Fig 1, 3 supported by a more rigid core member that may act as a stent 9 to provide structure to the dressing. The dressing may be used internally and may be used in the treatment of heamorrhoids / hemorrhoids. A retraction cord 7 may be provided to aid in removal of the dressing which may take the form of tube or cylinder. The foam may be pleated to provide full bodily contact when the stent is expanded. A ventilation tube Fig 1,15 may be provided to allow gas relief. The external sponge foam may be a fine pore silicon foam 3 to 6mm thick. The stiff supporting or carrier foam Fig 1, 5 may be made from gelatin, cellulose or any polymer material.

Description

(71) Applicant(s):

Alexander Roger Deas

King's Gate Lodge, DALKEITH, EH22 1ST,

United Kingdom (56) Documents Cited:

CN 204814984 U US 5939339 A US 5447499 A

US 8088093 B2 US 5480377 A US 20050249791 A1

Ahmed Teoman Naskali

Tarabya Bayiri Cad,, Sanatcilar Sitesi 27, Sariyer, Istanbul 34457, Turkey (58) Field of Search:

INT CL A61F

Other: WPI, EPODOC, TXTA

Soner Sirtmac

Pasa Mh.Guzelbahce Sk.Altunkamis, Apt.No:1 D:3, Ferikoy, Sisli, Istanbul 34377, Turkey (72) Inventor(s):

Alexander Roger Deas Ahmed Teoman Naskali Soner Sirtmac (74) Agent and/or Address for Service:

Alexander Roger Deas

King's Gate Lodge, DALKEITH, EH22 1ST,

United Kingdom (54) Title of the Invention: Layered hydrogel surgical dressing

Abstract Title: Laminated dressing having an anti-microbial hydrogel saturated foam outer layer and a support layer.

(57) A layered dressing has a sponge outer layer 1 saturated with an anti microbial hydrogel Fig 1,3 supported by a more rigid core member that may act as a stent 9 to provide structure to the dressing. The dressing may be used internally and may be used in the treatment of heamorrhoids / hemorrhoids. A retraction cord 7 may be provided to aid in removal of the dressing which may take the form of tube or cylinder. The foam may be pleated to provide full bodily contact when the stent is expanded. A ventilation tube Fig 1,15 may be provided to allow gas relief. The external sponge foam may be a fine pore silicon foam 3 to 6mm thick. The stiff supporting or carrier foam Fig 1,5 may be made from gelatin, cellulose or any polymer material.

Figure 2.

1/2 figure 1.

2/2 figure 2.

-..,

Application No. GB1701086.9

RTM

Date :29 June 2017

Intellectual

Property

Office

The following terms are registered trade marks and should be read as such wherever they occur in this document:

Spongostan

Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

TITLE OF INVENTION

Layered Hydrogel Surgical Dressing

Technical Field

The present invention relates to a surgical dressing for use in body cavities and in the emergency treatment of trauma injuries.

Background of the Invention

Surgical dressings and medicated pads which will absorb the discharge of bodily fluids are generally well-known in the medical arts and in the medical industry.

Following internal surgery, dressings are used to apply pressure to the wound site to aid haemostasis. In many cases these dressing remain in position internally, and are replaced periodically or in subsequent surgery. For example, following haemorrhoid removal dressings are usually replaced several times a day. Many types of dressing are known in the medical arts and in the medica

Dry dressings made from surgical wadding, mesh, bandages or sponges on tend to pull fluid from within the wound site, and bond to the wound site. When the dressing is replaced, the adhesion between the dressing and the wound damages the wound site and can be painful to the patient.

Some dressings are absorbable, for example, gelatin sponges under the trade-name Spongostan can remain in position: these are typically gelatin hydrostatic sponges - dry sponges. However, these apply limited pressure to the wound and are easily deformed when wet. losing contact with the wound.

Aqueous dressings commonly used for the treatment of burns and other skin wounds reduce pain by cooling the wound site initially, and promote healing by providing an aqueous environment that reduces the fluid tension across the wound. The aqueous dressing is typically 90% water, with a gelling agent, and described as a hydrogel. The purpose of the gelling agent is to keep the water in the dressing in contact with the wound.

There are many hydrogel dressings described in the prior art for burn and surface wound treatment. . For example, US US5429589 describes a dehydrated hydrogel that absorbs wound exudate with the benefit that it does not adhere to the wound. US4948575 A is an effervescent gei with a similar application. US4948575 A describes an alginate hydrogel for treatment of surface wounds. CN104288173A describes a chitosan based gel with around 50% water for use in haemorrhoid and gynaecological treatment, though with no indication of how it applies pressure or retains its form.

Hydrogels are delivered either as a gel directly to the wound site, or in a carrier such as a non-woven viscose sponge, or open-cell polymer sponge. Sponges for holding the hydrogel are much softer than those used for surgical dressings: the indentation load deflection is typically a tenth that of a surgical dressing sponge, in order to conform to the wound site. The softness, or high indentation deformation figure, for these sponges results in the hydrogel being squeezed out of the sponge if attempts are made to apply it internally.

The prior art includes dressings that try address these limits by combining a support layer and a hydrogel. For example:

EP2461863 A1 describes a surgical wound dressing with connected hydrogel beads on a support layer.

US7910135 B2 describes a shape retentive hydrogel dressing.

EP0785224B describes hydrogels with a high swelling capacity, where a hydrogel is combined with a base of very small particles, with the application for babies nappies and incontinence products. A similar method could be used in surgical applications.

The prior art also contains descriptions of dressings for specific internal applications. CN104043089 describes a dressing for haemorrhoid (haemorrhoid) treatment comprising a dressing suppository with a medical component and lists a series of traditional herbal components. A gel component is present in that invention as it comprises chitosan, glycol and carbopol but the dressing has a low water content.

The limitation of the prior art is they are unsuitable for internal use because either they do not apply sufficient pressure on the wound site, or fail to maintain the gel on the wound site, or are too rigid to absorb swelling, or sufficient malleable to be removed easily, e.g. through the rectum following haemorrhoid or vagina.

Object of the present invention.

It is an objective of the present invention to provide an internal surgical dressing that applies pressure to wound to promote haemostasis whilst not bonding with the wound site.

It is a further objective of the present invention to provide a dressing that provides an aqueous environment to promote healing and relieve pain.

It is a further objective of the present invention to prevent microbial growth within the dressing.

It is a further objective of the present invention to promote oxygen perfusion within the wound tissue.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a layered device with an external layer comprising a soft open cell sponge impregnated with an anti microbial hydrogel, and an internal structure that applies pressure to the wound without significant loss of hydrogel from the external sponge..

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and the advantages thereof and to show how the same may be carried into effect, reference will now be made, by way of example, without loss of generality to the accompanying drawings in which:

Figure 1 shows a dressing according to the present invention with an internal sponge structure. Where (1) is an external carrier foam, (3) is a hydrogel with anti-microbial properties, (5) is a substrate foam, (7) is an optional extraction cord. A ventilation hollow or tube (15) runs through the centre of this example because it is for rectal use, to allow gas to pass through the dressing.

Figure 2. shows a dressing according to the present invention with an internal stent structure, where (1) is a carrier foam, (3) is a hydrogel with anti-microbial properties, (7) is an extraction cord, (9) is a polymer stent, (11) is the stent form retainer.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described in detail by reference to the aforementioned figures and by use of example embodiments.

Examples of dressings for use following haemorrhoid surgery are given. This is a common type of surgery where internal dressings are used. The size and external shape of the dressing varies with other types of surgery, in a manner that would be apparent to a skilled surgeon.

In the Figures an external foam (1) is saturated in the hydrogel (3). Suitable foams are non-woven viscose foam, or open-cell polymer foam such as a silicone foam. The pore size should be as small as possible, to provide the maximum retention of the hydrogel and a fine external surface. The external foam is typically 3mm to 6mm thick.

Many hydrogels (3) are known, but for this application the example embodiment uses a hydrogel formed from Pure Water (90%), with a combination of Sorbitol and Sodium Carbomer for the remaining 10% by weight to form an aqueous gel.

Anti-fungal properties are added to the gel by adding a few percent of parabens, typically Propylparaben (E217), Ethylparaben (E215), and Butylparaben - these prevent the growth of moulds and yeasts within the gel. A further addition to the gel is phenoxyethanol, typically 0.8% by weight to the gel, as as a germicide.

In Figure 1, the carrier foam (5) is a stiff foam that can be a gelatin foam, a cellulose foam or a firmer polymer foam. It is not necessary to saturate the carrier foam (5) with hydrogel, (3) but a saturated foam has a benefit of providing a higher mass of hydrogel which delivers a longer lasting cooling effect, and hence pain relief, than a thin external foam (1).

The size of the dressing in Figures 1 and 2 for use in post haemorrhoid removal applications is 25mm diameter and 50mm long. For other applications the size may differ and shall be similar to that of conventional surgical dressings.]

An extraction cord (7) may be fitted in applications that require this.

In Figures 2 the hydrogel laden external foam (1) is expanded by the stent (9) when in place. When this occurs the external foam (1) thickness reduces and surface area increases. The external foam (1) is wound or pleated in Figure 2 such that when the stent (9) is expanded, the foam (1) expands with the minimum loss of thickness. However some reduction in thickness will still occur and this can result in gel being pressed out of the foam into the stent (9) area but the gel (3) retains contact with the foam because the gel viscosity is chosen such that the gel (3) does not run off.

Claims

WE CLAIM

1. A layered surgical dressing comprising an external layer of foam saturated with anti-microbial hydrogel, and an internal stiffening structure;
2. A device according to claim 1 wherein the said stiffening structure is a

5 carrier foam or gelatine sponge or cellulose sponge or polymer sponge, stiffer than than the external foam;
3. A device according to claim 1 wherein the said stiffening structure is a stent;
4. A device according to claims 1 to 3 where the external foam is a very fine

10 pore silicone;
5. A device according to claims 1 to 4 where the external foam is pleated so as to enable it to expand in diameter without significant loss of thickness.

Intellectual

Property

Office

Application No: GB1701086.9