[Application of modified pectoralis major myocutaneous island flap in head and neck surgeries]

To preserve the function of the donor site and good cervical shape, a modified pectoralis major myocutaneous island flap was designed.

The modified pectoralis major myocutaneous flaps were used to repair primarily the defect in head and neck surgery. In all 17 cases, six cases were patients with recurrence of larynx or hypopharynx cancer, four cases with hypopharynx cancer, three cases with base of tongue cancer, two cases with recurrence of maxillary cancer, one case with tonsillar cancer and one case with pharyngeal fistula after hypopharyngeal cancer surgery. Before operation, ultrasound was used to mark the projection of the pectoral branches of thoracoacromial artery, and the pectoralis major myocutaneous were designed according to the axle between lowest entering muscle point of the artery and the fourth intercostals perforator spot of mammary artery; the incision was designed to turn laterally in an oriental direction at the top of the flap and upward along the anterior axillary line; the internal pectoral nerve was reserved, as well as the partial lateral pectoral nerve. The flaps were transferred to recipient site either above or below the clavicle on the premise of the integrity of clavicular part.

The distance of the lowest entering muscle point of pectoral branche measuring during operation, which was all in sternocostal part, to the midpoint of inferior clavicula margin was (4.9 +/- 1.2) cm (average +/- s), and in 76.5% (13/17) of the patients, the location was coincidence by ultrasound. The length between entering muscle point and the fourth intercostals perforator spot of mammary artery was (1.8 +/- 0.5) cm. All the myocutaneous flaps were alive except one case. The flap was given up as a result of the vessel pedicle injure. The distal end of the flap was dehisced from the residual tongue in one case with base of tongue cancer and healed with changing dressing. Two pharyngeal fistulas in another two cases were healed with conserved treatment. The rate of the flap survival was 94.1% (16/17). Functions as adduction and adtorsion of major pectoral muscle were integrated within 4 weeks to 3 months. Also, the good looking of the neck and upper chest was maintained.

The location of pectoral branches of thoracoacromial artery and the site of the lowest entering muscle point marked by ultrasound detection could help the design of the flap. The modified pectoral' s major myocutaneous flap designing presented better functional protection and reach longer distance and left a better looking for neck and upper chest.