[Neurovascular infrahyoidal myofascial flap. Anatomic and topographic study of the innervation and blood supply].

Abstract

The neurovascular infrahyoidal myofascial flap: An anatomical and topographical study of the innervation and blood supply. 15 cadavers had bilaterally been examined for the topography of the upper thyroid artery and vein and of the lower cervical ansa, as an axial bundle of vessels and nerves for the infrahyoidal myofascial flap. With the injection of methylene blue the vascular territories of the upper thyroid artery had been demonstrated. The upper thyroid artery and vein could be found in all cases. This artery was deriving in 47% from the external carotid artery, in 30% from the bifurcation and in 23% from the common carotid artery. The vein flowed in 43% into the facial vein and in 37% into the internal jugular vein. In the remaining 20% several segmental veins were found, which flowed into the jugular vein separately. In case of a far caudally situated vascular bundle the radius of rotation can be limited in cranial direction. The voluntary innervation of the muscles of this flap is derived from the lower cervical ansa. The upper radix of the ansa can be found 1 cm in latero-cranial direction of the greater horn of the hyoid bone, where it is separating from the hypoglossal nerve. The upper thyroid artery is supplying the infrahyoidal musculature in the whole extension from the hyoid bone to the sternum. Therefore it is possible to develop a myofascial flap of 3.5 cm x 11.5 cm in size, which is pedicled at an upper vascular and nerval bundle. Depending on the radius of rotation defects of the floor of mouth, of the tongue and of the oro- and hypopharynx can well be covered with this new neurovascular myofascial flap.