An anatomical study of the arterial and nerve supply of the infrahyoid muscle

INTRODUCTION. Infrahyoid myocutaneous flap is of interest in head and neck reconstruction surgery given its versatility, and the quality of its cosmetic results. It represents the golden standard for reconstruction of extensive defects after resection of cancer. There are no sufficient references on the arterial supply to infrahyoid muscles. This information would be beneficial to improve the quality of surgical reconstructions as it will aid surgeons in planning their operations.

METHODS. Fourteen cadavers were unilaterally dissected. The cadavers were injected with red latex. The cervical arterial pedicle, and the neural supply of the sternohyoid (SH), sternothyroid muscle (STM)and superior belly of omohyoid (OM) were identified. The superior thyroid artery (ST) and ansa cervicalis (AC) were examined as they are the main supply for the infrahyoid myocutaneous flap. The length of the arterial pedicles was measured to evaluate their potential application in reconstructive surgery. SUMMARY. For the SH, two arterial pedicles originated from the ST and supplied it in 57.1%. The inferior pedicle was absent in 42.9%. As regards the STM, one arterial pedicle from the ST supplied its upper end in 57.1% of cases. In 14.3% of cases, the inferior thyroid artery also supplied it. As regards OM, two arterial pedicles originated from the ST and supplied its upper and lower ends in 64.3% of cases. SH usually had a double nerve supply from AC. In 57.1% of cases, its superior part was innervated by the nerve to the superior belly of OM. In 35.7% of cases, it received direct branches from AC. As regards STM, in 71.4% of cases, a common trunk arose from the loop and supplied the inferior part of both the SH and STM. The nerve supply to superior belly of OM originated from the AC below the loop.

CONCLUSIONS. These data will be useful for surgeons as precise knowledge of the location of vascular pedicles is required for the successful transposition of a myocutaneous flap.