TISSUE EXPANSION IN THE TREATMENT OF BURN SCARS

Caleffi E, Bocchi A., Toschi S., Montacchini G., Papadia F.

Divisione di Chirurgia Plastica, Parma, Italia

SUMMARY. Major post-burn scars are a serious morphological and functional problem and old techniques like skin grafts and distant flaps are not very effective to improve the final result. Expansion of the local skin allows us to obtain very large local flaps and the replacement of the scar tissue with a good skin for colour and texture. We have used the tissue expansion technique in the treatment of burn scars in the head and neck, trunk, upper and lower extremities. In the head and neck, tissue expansion is useful to obtain good results but the complication rate is higher than in the treatment of other pathologies with the same technique. Good results are obtained in the back where very large amounts of scarred tissue can be removed. In the thorax the morphological results are less satisfactory because of the hypertrophic scars resulting after the operation. In the thigh a good cosmetic improvement has very often been achieved; in the leg, on the contrary, we have observed the highest rate of complications: the use of tissue expansion in this area must be very careful and limited to selected cases.
In the last few years tissue expansion has improved thanks to technical refinements in plastic surgery.
In the past, the treatment of bum scars was carried out by the use of skin grafts or the transposition of local flaps. With skin grafts recurrence of contracture, chronic breakdowns and unsatisfactory cosmetic outcomes were observed; local flaps may be insufficient to resurface large defects after debridement or excision of a post-bum scar.

Expansion of the local skin makes it possible to obtain very large local flaps and to replace a great amount of scar tissue with a good skin for colour and texture (Argenta, 1985; Chang, 1986; Cohen 1988; Manders, 1984; Nordstrom, 1985; Radovan, 1979).
We have used the tissue expansion technique in the surgical treatment of burn scars in the head and neck, trunk, and the upper and lower extremities. We report a few cases to illustrate our surgical procedures.

A 48-year-old man had sustained a burn of the back 23 years previously. In recent years he observed a recurrent ulceration in the centre of the scar. A biopsy did not show malignant cells but the recurrence of chronic breakdown was an indication for surgical excision of the scar tissue. In the first operation two tissue expanders were placed; one (1200 cc) was inserted in the paravertebral area and the other (1700 cc) in the right gluteal region. Two months later partial removal of the scar including the ulcerated area and reconstruction with the expander flap were performed. A re-expansion was performed one year later and 3 tissue expanders were placed at gluteal and lateral the level of the paravertebral thoracic regions.
Three months later removal of the expander, excision of the scar and reconstruction were performed. The ultimate result is satisfactory; further refinements can he achieved with a final expansion.

A 32-year-old woman had sustained a bum of the face, neck and upper extremities at the age of six months. Scar and contractures of the cheek and oral region were inacceptable for the patient.
A preliminary expansion was performed by inserting an expander in the left side of the neck; a second expansion was carried out one year later on the opposite side of the neck: during expansion a breakdown was observed of the expanding tissue with partial exposure of the prosthesis. This complication did not impair the reconstructive procedure which yielded a satisfactory cosmetic result.

In our series tissue expansion has yielded satisfactory results if compared with old techniques such as skin grafts or local flaps. However, the tissue expansion complication rate is higher in the treatment of large post-burn scars than in the treatment of other pathologies such as haemangiomas, giant naevi, post-mastectomy defects, bone exposure, etc.
The extensive scarring probably weakens the surrounding skin and impairs microvascularity.
We have observed that the complication rate is different in the various body areas.
In the head and neck the treatment of post-burn alopecia is satisfactory; the coverage of extensive facial or neck defects is often less satisfactory than in the treatment of other pathologies with the same technique: impairment of the expanding tissue, inflammation and exposure of the implant may be observed. In the thorax the morphological results may be compromised by the high rate of hypertrophic scars after the operation.

Fig. 1 a) pre-operative view Fig. 1 b) first expansion Fig. 1 c) second expansion (one year later) Fig. 1 d) final result

Excellent results have been obtained in the back, where very large amounts of scarred tissue can be removed in a single operation; re-expansion is also reliable and very useful to perform removal of scars.
In the thigh, good cosmetic improvement has very often been achieved; in the leg, on the contrary, we have observed the highest rate of complications. The use of tissue expansion in this area must be very careful and limited to selected cases: probably the stiffness of the tissue impairs the venous and lymphatic function and causes complications during tissue expansion: the fibrosis surrounding scar tissue may reduce venous and lymphatic flow from the expanding area and compromise tissue subjected to continuous mechanical stretching.

Fig. 2 a) pre-operative view Fig. 2 b) first expansion Fig. 2 c) second expansion (one year later) Fig. 2 d) final result

On the basis of our experience, tissue expansion is undoubtedly a method of choice in the treatment of post-burn scars; expansion must by very careful where stiffness of the tissue or terminal vascularization is present (leg, finger). At the level of the knee, elbow and neck, a very large amount of expanded skin is always necessary to carry out adequate reconstruction.

RÉSUMÉ. Les cicatrices étendues causées par les brûlures constituent un grave problème morphologique et fonctionnel et les techniques utilisées par le passé, comme par exemple les greffes cutanées et les lambeaux à distance, ne réussissent pas à améliorer le résultat final. Les Auteurs ont utilisé la technique de l'expansion tissulaire dans le traitement des cicatrices causées par les brûlures à la tête, au cou et aux extrémités supérieures et inférieures. A la tête et au cou l'expansion tissulaire permet d'obtenir de bons résultats, même si le taux des complications est plus haut par rapport au traitement, avec la même technique, des autres pathologies. Il est aussi possible d'obtenir de bons résultats au dos parce que de grandes quantités de tissu cicatrisé peuvent être enlevées. Au thorax les résultats morphologiques sont moins satisfaisants à causes des cicatrices hypertrophiques qui sur-viennent à la suite de l'acte opératoire. A la cuisse on peut obtenir une bonne amélioration cosmétique; à la jambe, au contraire, on observe le taux plus haut des complications: dans cette partie du corps l'expansion tissulaire doit être effectuée avec grande attention et seulement chez des patients sélectionnés.

BIBLIOGRAPHY

1. Argenta L.C.: Advance in tissue expansion. Clin. Plast. Surg., 12: 159, 1985.
2. Chang T.S.: Application of tissue expansion in the treatment of post burn skin contractures and alopecia. Eur. J. Plast. Surg., 9: 7, 1986.
3. Cohen K.l.: Tissue expansion for the reconstruction of bum defects. J. Trauma, 28: 158, 1988.
4. Manders E. K.: Soft tissue expansion: concepts and complications. Plast. Reconstr. Surg., 74: 493, 1984.
5. Nordstrom R.E.A.: Scalp stretching with a tissue expander for closure of scalp defects. Plast. Reconstr. Surg., 75: 578, 1985.
6. Radovan C.: Development of adjacent flaps using a temporary expander. Plast. Reconstr. Surg., 2: 62, 1979.