Ann. Medit. Burns Club - vol. VII - n. 4 - December 1994

USE OF AMNIOTIC MEMBRANES AS BIOLOGICAL DRESSINGS IN CONTEMPORARY TREATMENT OF BURNS

Atanassov W, Mazgalova J.**, Todorov R*, Stereva K***, Trencheva W*

* Section of Thermal injury and Plastic Surgery,
** Department of Tissue Conservation, Pirogov Emergency Institute,
*** University Hospital of Obstetrics and Gynaecology, Sofia, Bulgaria

SUMMARY. The positive results of burn treatment with amniotic membranes are described. The indications for the clinical use of amnion are defined. It is used in promoting early epithelial regeneration and it reduces scar hypertrophy,

The role of amniotic membranes as biological dressings in the treatment of partial-thickness burns is well established (1, 2, 4, 5, 7). Positive clinical results in their application have been reported. The 'results are accompanied by reduction of pain, decreased bacterial count in the burn wound and promotion of epithelialization (2, 3, 6). The use of amniotic membranes causes fewer complications than synthetic skin covers (4, 8).

Foetal membranes were obtained fresh from deliveries (seronegative to syphilis, hepatitis B and AIDS). The chorion was removed. The isolated amnion was washed with saline, stored in bags containing 70' ethyl alcohol and kept at room temperature. Before use, the amnion was washed in sterile saline.
The study included 29 patients, 12 in the age group 2777 yr and 17 children aged between 3 months and 16 yr. Amniotic membranes were applied to 21 patients in whom the total burn area ranged from 0.5% to 60% BSA. In five patients amnion was used for treatment of donor sites, while three patients were treated locally with amnion on the occasion of traumatic wounds. All injured places were cleaned with 1% chlorhexidine glyconate solution at the beginning of treatment.

The results were observed in patients between 5 and 20 days after the first covering of the wounds with amnion. Nine of the patients were treated on admission to the clinic, six on the second or third day after their thermal injury, five children were placed on Klinitron beds and three in air-therapeutic conditions. The amniotic dressings were not covered in six patients.

Fig. 1 - Ten-year-old child with fire burn of the face, covered with amnion. Appearance on admission.

The results of the application of amniotic membranes are as follows:
Fresh superficial burns of the face and upper extremities were covered with amnion during the first three days after the injury. Amnion adheres to the wound and dries rapidly, forming a thin crust. The membrane peels off 12-15 days after application. A well-epithelialized surface was seen at the end of treatment (Figs. 1, 2, 3).

Fig. 2 - Appearance after 6 days of covering with amnion. Same case.

2. Different-depth dermal burns were treated with amnion. Burned skin covered with amnion during the first 24 h after the trauma kept its surface dry for up to seven days. This is very important for wounds on the back of the body. Amnion is no obstacle to the removal of necrosis or to the application of auto- and allografts. Its use during the first three days after the burn prepares the injured area for early tangential necrectomy. When early necrectomy was contraindicated, the elimination o,f necrosis was completed by chemical necrectomy through the amniotic membranes. A well-defined young epithelium was seen when the dried amnion was removed (Figs. 4, 5).
3. Amnion was used to cover mesh-grafts during the treatment of large bum sufaces. Dried amnion serves as a barrier to water loss through the holes, diminishes pain and stops bacterial invasion. A fine bright-pink epithelium was seen after amnion separation. The formation of hypertrophic scars was not observed (Figs. 6, 7).

4. Amniotic membranes were used for the treatment of skin donor sides. When amnion was meshed, coagula were formed and the dressings were removed. Epithelialization was observed within two weeks when the mesh-graft dermatom perforated the amnion-covered donor site. Donor wounds treated in this manner caused less pain, and infection was reduced in comparison to conventional clinical dressings.
5. Application of amnion for the treatment of wounds after dermoabrasion eliminated bleeding at the end of the operation. The amniotic membranes were dried by air from an air-installation. The epithelialization established in this case depended on the depth of dermoabrasion.
6. Granulating wounds covered by amniotic membranes were influenced by local infection and plasmorrhagia. Granulation tissue is a contraindication for the amnion treatment.

Amniotic membranes have been used as a biological dressing in the treatment of burns of different dermal depth. We returned to this kind of wound cover because of its easy availability and low cost. We try here to define some of the indications for the clinical use of amnion.

Fig. 4 - Different-depth dermal bum covered with amnion on first day after admission. Fig. 5 - Same case. The superficial part of the burn area was epithelialized under the amnion. The granulation wound surface was prepared for operation with autografts. Fig. 6 - Auto-meshgrafts covered with amnion during the operation. Fig. 7 - Appearance at end of treatment. Same case.

Our results clearly show the usefulness of the early application of amniotic membranes in the treatment of fresh superficial bums. Large injured areas were treated by amnion during the first 24 h after injury. With air-conditioning, amniotic membranes remained dry for a week. Their application was not an obstacle to removal of necrosis. We observed a healthy effect of amnion when used for meshgraft covering. We consider it to be effective in view of the promotion of epithelialization, reduction of pain and limited infection. Amniotic membranes are economical and easily available. Amnion is not "taken", it only acts as a protective biological dressing. It does not survive on dead tissue and dissolves on granulating areas. It is useful in promoting the early regeneration of epithelium and reduces scar hypertrophy.

RESUME. Les auteurs décrivent les résultats positifs obtenus dans le traitement des brûlures avec les membranes amniotiques. Ils définis sent les indications pour l'emploi clinique de l'amnios, qui est utilisé pour promouvoir la régénération épithéliale précoce. En outre il réduit l'hypertrophie cicatricielle.

BIBLIOGRAPHY

1. Colocho G., Graham W.P., Green A.E. et al.: Human amniotic membranes as a physiological wound dressing. Arch. Surg., 109:370-3, 1974.
2. Haberal M., Oner Z., Bayraktar V. et al.: The use of silver nitrate incorporated amniotic membranes as a temporary dressing. Burns,7.13: 159-63, 1987.
3. Robson M.C., Krizek T.J.: The effect of amniotic membranes on the bacterial population of infected rat burn. Arm. Surg., 177: 144-7,1973.
4. Robson M.C., Krizek T1, Koss N. et al.: Amniotic membranes as a temporary wound dressing. Surg. Gynec. Obst., 136: 904-6, 1973.
5. Sawney C.P.: Amniotic membranes as a biological dressing in the management of burns. Burns, 15: 339-42, 1989.
6. Thomson P.D., Parks D.H.: Monitoring banking and clinical use of amnion as a burn wound dressing. Arm. Pl. Surg., 7: 354-6, 1981.
7. Viswarnath Rao T., Chandraselcharan V.: Use of dry human and bovine amnion as a biological dressing. Arch. Surg., 117: 891-6, 1981.
8. Ward D1, Bennett J.P.: The long term results of the use of human amnion in the treatment of leg ulcers. Br. J. Pl. Surg., 37: 191-3, 1984.

The scientific programme includes:

Burns in the elderly
Immunology and topical treatment of lesion
Face and hand burns (immediate and long-term results)
For further information contact:

Prof. Dino Barisom, Divisione di Chirurgia Plastica la
Ospedale di Borgo Trento
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