THE NEUROVASCULAR INFRAHYOID MYOFASCIAL F LAP - AN ANATOMICAL AND TOPOGRAPHICAL STUDY OF THE INNERVATION AND BLOOD-SUPPLY

Fifteen cadavers were examined bilaterally for the topography of the s uperior thyroid artery and vein an lower cervical ansa as an axial bun dle of vessels and nerves for the infrahyoid myofascial flap. Using in jections of methylene blue, the vascular territories of the superior t hyroid artery were demonstrated. The superior thyroid artery and Vein could be found in all cases. This artery was derived in 47% of cases f rom the external carotid artery, in 30% from the bifurcation and in 23 % from the common carotid artery. In 43% of cases the vein flowed to t he facial vein and in 37% to the internal jugular vein. In the. remain ing 20%, several segmental veins were found that flowed separately to the jugular vein. In case of a far caudally situated vascular bundle t he radius of rotation was limited in a cranial direction. The voluntar y innervation of the muscles of the infrahyoid myofascial flap was der ived from the lower cervical ansa. The upper radix of the ansa was fou nd 1 cm in latero-cranial direction to the greater horn of the hyoid b one, where it separated from the hypoglossal nerve. Present findings s how that the superior thyroid artery supplies the infrahyoid musculatu re in its whole extension from the hyoid bone to the sternum. It is th erefore possible to develop a myofascial flap of 3.5 cm X 11.5 cm in s ize, which can be pedicted at an upper Vascular and neural bundle. Dep ending on the radius of rotation, defects of the floor of mouth, tongu e and oro- and hypopharynx can be covered sufficiently with this neuro vascular myofascial flap.