SMALL-SIZED FULL-THICKNESS BURNS TREATED WITH A HYDROCOLLOID DRESSING (VARIHESIVE GEL CONTROL)

Serna C., Terren J., Pous S., Hidalgo J.C., Mallent J., Frances J., Mirabet V.

Plastic Surgery and Burns Centre Department, La Fe University Hospital, Valencia, Spain

SUMMARY The aim of this study was to ascertain the effect of the hydrocolloid dressing Varihesive Gel Control on the healing of full-thickness burns with a maximum diameter of 4 cm, in order to investigate alternatives to treatment by split-skin autograft Or even, in some cases, direct closure of the wound. Twenty out-patients with small full-thickness burns were treated with the hydrocolloid dressing and were periodically checked to evaluate epithelialization. It was found that this dressing helped complete healing in some cases and in others reduced the size of the wound, giving the wound bed the correct properties for receiving a graft.

Introduction
Throughout the history of burn treatment different types of dressings have been used (3). They have been made from natural or synthetic materials (with or without pharmacological agents); there are also biological dressings and even artificial skin.  The purpose of using them is to protect the burn from outside agents which might impair the wound's condition, to prevent pain as far as possible, to absorb the exudate, to act a barrier against infection, to facilitate debridement of sloughs and eschars, and even to promote epithelialization (1, 2). It has been proved that by occluding the wound a very favourable environment is created for a new epithelium to form more quickly (6). This discovery has brought forward a hydrocolloid dressing (Varihesive Gel Control) which has properties that facilitate burn wound healing.

Material and methods
Material
The composition of Varihesive Gel Control is described in Table 1. It is commercially available in three different sizes. The outer surface is impermeable to water, gases, vapours and organisms; this characteristic permits the creation of a humid medium in the wound (4). The constituents of the dressing form a gel when they come into contact with the wound exudate, which facilitates its removal without damage to the newly formed tissues. Twenty patients were selected, 12 females and 8 males. Their ages varied from 16 months to 68 years. All the burns involved were of full skin thickness, and their maximum diameter was equal to or less than 4 cm.

Table 1 Composition of dressing

• Outer layer of polyurethane.
• Inner matrix formed by polymers, which include three hydroactive or hydrocolloidal substances: sodium, carboxymethylcellulose, pectin and gelatine.

The aetiology of the burns was varied (scaldsI fire, solid contact) but no electrical burns were included, since their evolution is erratic and different from that of other burns. In 2 patients the bums were on the chest, in another 2 on the back, in 6 on the upper limb, in 3 on the abdomen and in 7 on the lower limb.

Methods
All of the patients selected were treated in the Out-patients Department of the Burns Unit, at La Fe University Hospital. The application of the Varihesive Gel Control dressing was carried out as follows:

• cleansing of the wound with soapy water or saline;
• application of the dressing after removal of moisture from the area;
• change of dressing every 5 days (5), checking the condition of the wound bed, the edges and the size of the wound (measuring maximum and minimum diameter and calculating the area as for an ellipse);
• recording any complications (infection, exudate leaks, pain).

The trial was considered completed when in two successive dressings the size of the burn had not changed, or when epithelialization was complete.

Results
The 20 patients were examined as out-patients and none of the courses of treatment was discontinued for reasons other than the criteria of study completion. All of the burns involved full skill thickness and their maximum diameter was no larger than 4 cm. 1. In all 20 cases, Varihesive Gel Control facilitated the formation of clean granulation tissue, which afforded an ideal bed for a split-skin graft.

Fig. 1 35-year-old woman with scald burn on left lower limb. 1 a) Appearance of the burn on first day of trial. Size: 2.5 x 1.5 cm. 1 b) Wound after 15 days: size of bum markedly reduced. 1 c) After 23 days burn completely epithelialized.

Table 2 Mean epithelialization percentages

Table 3 Mean epithelialization percentages

2. Complete wound closure occurred in 4 cases, where the burns had a surface area less than 5-CM2. The mean healing time in these cases was 24.5 days (Fig. la, b, c). The mean epithelialization percentage observed during out-patient treatment is shown in Table 2.
3. In the remaining 16 cases, hypertrophic granulation tissue occurred, which impeded complete epithelialization of the wounds, so that in the following two dressings there was no change in size. All of these burns had a surface area larger than 5 CM2. The mean epithelialization percentage in these 16 cases is shown in Table 3.
Within 14 to 21 days (average 17.5 days) after starting the use of Varihesive Gel Control, this treatment was discontinued and definitive therapy was achieved, with split-skin grafts (14 cases) or direct closure of the wound (2 cases) (Fig. 2a, b, c).

Fig. 2 12-year-old boy with fire burn on abdomen. 2 a) Burn on first day of trial. Size: 3.5 x 2 em. 2 b) Appearance of the burn after 10 days. 2 c) After 15 days size of wound is unchanged.

4. All of the patients involved in the trial accepted the dressing, because of its comfort, large bandages not being required, and because its removal was painless. There was no haematoma collection under the dressing. No infection occurred. In three burns where the wound beds contained fibrin stretches and small amounts of slough, serous exudate was found during the first inspection, a result of the debridement effect claimed for the dressing (4).

Discussion
Our purpose was to ascertain whether the hydrocollold dressing Varihesive Gel Control can be used in the treatment of small full-thickness burns.
It, is true, that skin autografts are..an excellent therapy; in small areas they can be performed with a local anaesthetic, the graft takes in a few days (5-7 days), and the healing period is short. The result is also aesthetically acceptable. However, it must be emphasized that this means two bloody areas which have to heal (the donor site and the receiving site), and sometimes the graft does not take.
Moreover, some of these burns can be treated by direct closure when the patient initially consults the doctor. This requires local anaesthesia, and the result is a healing by first intention (which is always aesthetically preferable to healing due to closure by second intention), although not all small burns can be treated in this way.
We did not intend to show with this trial that treatment with Varihesive Gel Control is better than the other two possibilities mentioned above: our purpose was to provide another valid alternative which avoids surgery and is comfortable and not painful for the patient, and which does not involve a prolonged healing period. Our result, 24.5 days on average, is better than that of Hermans' series (5) with a mean epithelialization time of 29.5 days for this type of bum.

RESUME Cette recherche vise a vérifier Peffet du pansement hydrocollo'fdal Variliesive Gel Control sur la cicatrisation des brélures A toute &paisseur avec un diam&re maximum de 4 cm, dans le but d'&tudier des alternatives au traitement moyermant l'autogreffe A épaisseur variable ou rn~me, clans certains cas, la fermeture directe de ]a plaie. Vingt malades en consultation externe atteints de petites brélures ~ toute épaisseur ont W traités avec le pansement hydrocolloYdal et controllés périodiquement pour évaluer 1'épithélialisation. Les auteurs ont trouvé que le pansement Varihesive Gel Control a contribué d la cicatrisation compl~te ou bien il a réduit la superficie de la plaie, tout en créant les conditions les plus appropriées pour la greffe.

BIBLIOGRAPHY

1. Alvarez O.M., Mertz P.M., Eaglstein W.H.: The effect of occlusive dressings on collagen synthesis and re-epithelialization in superficial wounds. J. Surg. Res. 35: 142-48, 1983.
2. Baxter C.: Homografts and heterografts as a biological dressing in the treatment of thermal injury. First Annual Meeting Society German Plastic Surgeons, Munich, 1970.
3. Boswick J.A. et al.: "The art and science of burn care", 53-56. Aspen, Rockville (Maryland), 1987.
4. Convatec, Squibb: Duoderm hydro-active dressings. Technical Booklet, 1983.
5. Hermans M.H.E.: Hydrocolloid dressing (Duoderm) for the treatment of superficial and deep partial thickness burns. Scand. J. Plast. Reconstr. Surg., 21: 283-285, 1987.
6. Lawrence J.C.: The physical properties of a new hydrocolloid dressing. An Environment for Healing Symposium, Royal Society of Medicine Congress & Symposium, series 88: 69-76, 1985.