RECONSTRUCTION OF SECONDARY BURN DEFECTS OF THE HEAD AND NECK WITH CONTROLLED TISSUE EXPANSION

Cohen M., Marschall M.A., Tsutsos D.A.

Division of Plastic and Reconstructive Surgery, University of Illinois Medical Center, Chicago and Cook County Hospital, Chicago, U.S.A.

SUMMARY. The advantages of tissue expansion as a reconstructive technique in secondary burn defects in the head and neck area are described. The results of treatment in 23 patients are given. Apart from some minor disadvantages, tissue expansion proves to be a good, cost-effective and safe technique, especially in the case of burn alopecia.

Introduction
Tissue expansion has recently become a well-accepted alternative technique in reconstructive surgery. It can be applied, among other purposes, for the reconstruction of secondary burn defects in the head and neck area with good results.

Material and method
Twenty-three patients with 29 secondary burn defects in the scalp, face and neck were treated with this technique over the last 8 years. The location of burn scar was: 21 in the scalp, 3 in the face and 5 in the neck. The size of the defect ranged between 10 CM2 and 280 CM2. One to three expanders were used for each defect. They were expanded gradually for a period of 3 to 8 weeks. The interval between two sequential injections was 5-7 days. As soon as expansion was completed, the reservoir(s) were removed and the expanded skin advanced to cover the defect.

Results
Good functional and aesthetic results were obtained in the majority of the patients (Fig. 1, 2). In two patients undergoing reconstruction for a facial and scalp burn respectively, the expander became exposed early during expansion and had to be removed, while in two other patients partial exposure of the reservoir occurred near the end of the expansion. Both patients were operated on immediately, and after intraoperative additional expansion the defect was covered without any other problems. One patient developed seroma within the pocket of the reservoir which required drainage, reinsertion of the reservoir, and continuous suction drainage. The remaining 18 patients had an uneventful course.

Discussion
The treatment of secondary burn defects is a great challenge for surgeons who are asked to correct deformities following severe burns. There are several methods for treating these deformities, such as serial excisions, the use of split- or full-thickness skin grafts, local or distant flaps and, recently, tissue expansion.
Tissue expansion was first described and popularized by Radovan (1,, 2).
Small areas of alopecia in the scalp and hair-bearing face can be treated by serial excisions, punch grafts, or local flaps. However, for larger areas, it is possible to find the necessary hair-bearing skin only by using the tissue expansion technique. Skin grafts and flaps have been used to cover facial and neck burn defects with good functional results. The final appearance, however, is undesirable, since large skin grafts, even within the facial units, do not have the characteristics and the quality of the surrounding skin, and large local flaps result in unacceptable donor-site scars. Tissue expansion is very valuable in these cases, as it provides skin of similar colour, thickness and texture to the surrounding tissues. Tissue expansion can also be used to correct depressed skin grafts of the face and neck (3, 4).
The tissue expansion technique requires two operations and several out-patient visits for gradual expansion. To achieve the best result and to avoid possible complications we have to select the patients and follow certain technical procedures. It is necessary to determine if a patient will benefit fiom tissue expansion or from another reconstructive procedure. The patient's understanding of the special problems and of the duration of tissue expansion is required because cooperation is necessary. It is advisable to plan carefully the number, size, shape and position of the reservoirs.

Fig. 1 a. 12-year-old boy with 8x12 em area of bum alopecia in right side of scalp. Fig. 1b. One tissue expander was placed in subgaleal plane medial to defect. Fig. 1c. the expander was removed, the scar excised and normal skin sutured without tension Fig. 2a. 27-year-old patient with 12x15 cm, area of bum alopecia in midline of scalp. Fig. 2b. Two tissue expanders were placed around defect. Fig. 2c. Post-operative view 1 month after removal of expanders and reconstruction.

.'The expanders must be placed in large pockets, radial to the incisions, under healthy tissue, not under skin grafts or old scars, and away from areas of possible future local flaps (5). The worst complication of tissue expansion is necrosis of the overlying skin with extrusion of the expander. This complication can be minimized with meticulous surgical technique. If it occurs in the early stages, as in two of our cases, the reservoir should be removed, the wounds allowed to heal and expansion tried again several months later. However, if the procedure is close to complete expansion and there is no evidence of infection, as was the case in another of our patients, rapid intra-operative expansion followed by definitive reconstruction should be attempted (3).
This method of tissue expansion has many advantages. The surgical technique is relatively simple and does not require special skills such as microsurgery. The operation is usually done under local anaesthesia. The operative time and hospitalization are very short. The coverage of defects is performed with tissue of similar quality and characteristics to the surrounding tissues, which is of great importance for the head and neck areas. Finally, there is no donor-site scar.
The disadvantages of the method are the need for a two-staged procedure, the multiple out-patient visits for serial injections, the cost of the reservoir(s), and the temporary distortion of the head and neck area by the reservoir.
From cup experience and that of others, we conclude that tissue expansion is a good, cost-effective and safe alternative technique for the reconstruction of selected secondary bum defects of the head and neck area. It is certainly the method of choice for the reconstruction of burn alopecia defects.

RESUME Les auteurs décrivent les avantages de Vexpansion du tissu cornme technique de reconstruction dans les défauts secondaires dus aux brOlures. Us présentent les résultats du traitement de 23 patients. A part que1ques désavantages mineurs, Pexpansion du tissu se niontre une technique valide, sére et efficace pour le cofit, en particulier dans les cas d'alopécie par bralure.

BIBLIOGRAPHY

1. Radovan C.: Development of adjacent flaps using a temporary expander. Plast. Surg. Forum, 2: 62, 1979.
2. Radovan C.: Tissue Expansion in soft tissue reconstruction. Plast. Reconstr. Surg., 74: 482-490, 1984.
3. Cohen M., Marschall M., Shafer M.J.: Tissue expansion for the reconstruction of Bum Defects. Journal of Trauma, 28: 158-163, 1988.
4. Cohen M., Dolezal R., Shultz R.: Tissue expansion in reconstructive surgery. Contemporary Surgery, 30: 21-31, 198T
5. Achauer B.: Dealing with Scars. In "Bum Reconstruction", Ist ed., 1-12. Thieme Medical Publishers. Inc., New York, 1991.