THE USE OF TISSUE EXPANSION FOR RECONSTRUCTION OF POST-BURN ALOPECIA

Zaki M.S.

Plastic Surgery Unit, Faculty of Medicine, Cairo University, Egypt

SUMMARY. Controlled tissue expansion was used for scalp reconstruction in ten patients with post-burn alopecia. The time between the bum injury and reconstruction ranged between 3 and 21 years. Expanders with a remote valve were used in this series. They were introd ' uced either through a remote incision or by a paralesional approach. Multiple expanders were used when the dimensions of the defect exceeded 10 x 18 cm. The expanders were serially filled starting two to three weeks post-operatively. The expansion was carried out usually twice per week, guided by both patient tolerance and tissue response. The end of the expansion period is reached when the measured length of the expanded flaps can give the needed advancement to reconstruct the scalp defect. The clinical results showed that tissue expansion is an ideal technique for reconstruction of post-burn alopecia, and it has several advantages over other surgical procedures.

Treatment of large areas of post-burn alopecia constitutes a real problem for the reconstructive surgeon. The conventional methods of rotational scalp flaps, serial excision, microvascular flap transfer and free hair transplantation have many drawbacks including lengthy hospital stays, flap necrosis and inability to cover major scalp defects (1, 2, 3,). Recently, the introduction of controlled tissue expansion to treat scalp defects has started a new era of reconstruction (4,5).
The aim of this article is to report my experience in the use of tissue expansion for reconstruction of post-bum alopecia.

Ten patients with post-burn alopecia were treated by tissue expansion, 6 females and 4 males. Their ages ranged between 5 and 25 years. The time between the bum injury and reconstruction ranged between 3 and 21 years. The surface area of alopecia was 20-40% of the total hair-bearing scalp.

Pre-operative measurement of the defect and donor site selection of non-involved areas of hair-bearing scalp were evaluated for every patient. Expanders with a remote valve, both rectangular and rounded, were used in this series (Fig.1).
The size and number of tissue expanders needed to produce enough tissue to cover the anticipated defect were decided before surgery (6).
Multiple expanders were used when the dimensions of the defect exceeded 10 x 18 cin (4 cases). The expander was introduced under general anaesthesia, either through a radial incision away from the bald area (8 cases) or by using a paralesional approach (2 cases).

A pocket in the subgaleal space about 1 em larger than the expander base was created to accommodate the expander. The remote valve was embedded within the subcutaneous tissue of the lateral neck, at least 5 em away from the expander, and was easily palpable. The integrity of the expander was then tested by injecting about 50 cc sterile saline. This amount of saline was usually left in the expander to allow obliteration of any dead space and prevent haematoma collection. Lastly, the wound was closed with a suction drainage which was removed after 24-48 hours.
The expanders were serially filled starting two to three weeks post-operatively. The expansion was carried our usually twice per week, guided by both patient tolerance and tissue response. The end of the expansion period was reached when the measured length of the expanded flaps gave the needed advancement to reconstruct the scalp defect. At the second operation, the expander was removed through the original incision. Then the expanded flap was used to reconstruct the bald areas of the scalp. A course of broad spectrum antibiotics was prescribed for all patients during and after each surgical interference.

In the series, it was possible to completely reconstruct the scalp defects of 7 patients (70%) after the two stages, using tissue expansion (Fig. 2, 3). In the remaining 3 patients, additional scalp flaps or re-expansion were needed to reconstruct residual areas of alopecia.
Infection without extrusion of the expander occurred in one patient only (10%). Permanent hair loss of the expanded flap, haematoma collection and flap necrosis were not encountered in this series.

Fig. 2 - (A) 6-year-old child with post-bum alopecia; (B) After expansion of the scalp with 250 cc tissue expander over a period of 1 1/2 rnonths; (C) and (D) Post-operative pictures after excision of the bald area and reconstruction by the expanded flap.

There is no tissue in the human body which can effectively simulate lost scalp (4). The introduction of controlled tissue expansion in the treatment of scalp defects is thus considered to be a breakthrough in reconstructive surgery. The use of this technique for the treatment of post-burn alopecia has been reported (5).
It has several advantages over many conventional plastic surgery techniques. Firstly, it provides skin with an ideal match in consistency, sensation and hair-bearing properties. Secondly, it leaves no donor defects. Thirdly, tissue expansion provides reliable delayed flaps which are well vascularised.
However, the technique of tissue expansion has some disadvantages. These include the multiplicity of stages to complete reconstruction and the change of normal body contour during the expansion period (6).
The results of the present series have shown that by tissue expansion total reconstruction of post-burn alopecia could be achieved in 70% of the treated patients with two operations only. Most of these patients could not be easily managed by any of the other conventional reconstructive techniques. Also, the incidence of post-operative complications was very low.

Fig. 3 - (A) 21-year-old man with extensive post-bum alopecia of 20 years' duration; (B) Lateral pre-operative view of the same patient; (C) and (D) After expansion of the scalp with 400 cc and 250 cc tissue expanders over a period of 2 months; (E), (F) and (G) Post-operative pictures to show complete reconstruction of the scalp.

Concerning the age of patients, delay of the operation till the age of 5 years is recommended in order to avoid the possible complication of pressure necrosis of the skull bones and to be able to communicate easily with the older child.
Proper patient selection is very important to achieve a successful outcome. The patient must realize the steps of tissue expansion before surgery. Also, meticulous care and psychological support must be provided by the family and the surgeon during the period of disturbace of the normal body contour.
In conclusion, controlled tissue expansion is highly recommended for reconstruction of large areas of post-burn alopecia. The procedure is safe with minimal complications and is superior to other conventional methods of scalp reconstruction.

RÉSUMÉ. L'expansion contrôlée tissulaire a été utilisée pour la reconstitution du cuir chevelu chez 10 patients avec alopécie à la suite de brûlure. Le temps passé entre la lésion thermique et la reconstitution variait de 3 jusqu'à 21 ans. Dans cette série nous avons utilisé des expanseurs avec valve à distance ou une approche paralésionelle. Quand la partie intéressée a les dimensions supérieures à 10 x 18 cm, nous avons utilisés les expanseurs multiples. Les expanseurs; ont été remplis en série à partir de 2 ou 3 semaines après l'acte opératoire. L'expansion a été effectuée normalement deux fois par semaine, selon la tolérance du patient et la réponse tissulaire. La phase de l'expansion est terminée dès que la longueur mesurée des lambeaux en expansion est suffisante pour reconstituer le défaut du cuir chevelu. Les résultats cliniques ont montré que l'expansion tissulaire est une technique idéale pour la reconstitution de l'alopécie à la suite de brûlure qui offre plusieurs avantages par rapport à d'autres procédures chirurgicales.

BIBLIOGRAPHY

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