The infrahyoid musculocutaneous flap in head and neck reconstruction

The infrahyoid musculocutaneous flap (IHMF), as first described by Wang in 1986, is mainly nourished by the superior thyroid vessels through the perforators of the infrahyoid muscles (i.e., sternohyoid muscle, sternothyroid muscle, superior belly of the omohyoid muscle). This thin flap, usually extending from the hyoid bone to the sternal notch at the central part of the anterior neck, provides a skin island of about 4 by 8 cm. After these muscles have been divided from their origins, the flap can be freely transferred on its pedicle of superior thyroid artery to cover the soft tissue defect created after surgical ablation of cancer of the midface, parotid region, oral cavity, oropharnyx, or hypopharynx. From April 1987 to October 1990, our department successfully performed this flap procedure in 22 patients (cancer of the buccal mucosa 8, lower gum 5, floor of mouth 2, tongue 2, lower lip 2, parotid gland 1, skin 1, hemangioma of buccal mucosa 1). Two were treatment failures, three had partial dermal necrosis (distal third of flap surface), and the remainder had no major complications. The donor sites were closed either primarily or by means of a small, local skin flap. Contraindications to the flap are previous thyroid surgery, radical neck dissection, irradiation to the anterior neck, and hairy neck skin. We believe our results indicate that the IHMF is a versatile, reliable flap that may be used in combination with other regional flaps, such as the pectoralis major flap. It obviates the need for a microvascular free flap in many cases.