The switch flap in eyelid reconstruction.

PURPOSE: Full-thickness eyelid defects are conventionally reconstructed by either a Hughes flap or a Cutler-Beard bridge flap. The switch flap is an alternative method and is not very widely practiced. The author has used this method for repair of large full-thickness eyelid defects and describes her experience with the use of this technique.

METHOD: Eight cases of large full-thickness eyelid defects resulting from excision of tumours such as basal cell carcinoma (bcc), squamous cell carcinoma (scc) and sebaceous gland carcinoma (sgc) were taken for repair using the switch flap technique. The technique involves switching a full-thickness flap on a pedicle to fill a defect from lower lid to upper or vice versa. The pedicle is divided in three weeks. The recipient lid is reconstructed by direct closure and the donor lid by direct closure with or without cantholysis or sliding flap, or it is left to heal by second intention. The patients were followed up frequently in the first few weeks according to need, at six months, and then every year for five years before discharge. At these visits, contour of lid, condition of wound, cornea and donor site were examined for infection, dehiscence, corneal ulcer, notching, trichiasis, and recurrence. The preoperative and postoperative photographs were also compared.

RESULTS: Out of the eight cases of eyelid defects, one was from squamous cell carcinoma, three were from sebaceous gland carcinoma, and four were from infiltrative basal cell carcinoma. Using the switch flap technique, the defects resulting from their excision were completely covered in all cases. The main complication was a corneal ulcer in cases 1 and 3 where the flap had crossed the central cornea. A bandage contact lens was inserted until the division of the flap. The main morbidity was the blurred vision until the flap is divided, especially in the cases of reduced vision in the other eye. At about 4-6 weeks post flap division, the recipient and donor sites have healed completely, even when the donor lid was left to heal by second intention (case 4). There was no trichiasis, notching or notable deformity, and the morbidity was minimal. A comparison between preoperative and postoperative photographs shows satisfactory results with the switch flap technique.

CONCLUSION: The author has found the switch flap technique very useful for reconstruction of large full-thickness eyelid defects resulting from tumour excision as this method results in complete repair of defects with a full-thickness flap, tarsus, lid margin and eyelashes and without causing notable deformity at the donor site. The switch flap can successfully replace the Hughes flap technique and Cutler-Beard technique for repair of large eyelid defects.