Modified free functional split gracilis flap design for periorbital and perioral smile reanimation in patients with total flaccid facial paralysis: A cadaveric study.

[BACKGROUND] Facial reanimation after total flaccid facial paralysis requires natural smile animation with participation of both periorbital and perioral compartments.

[OBJECTIVE] To define detailed anatomy of gracilis muscle flap and investigate anatomical feasibility of split muscle flap transfer for periorbital and perioral smile reanimation.

[MATERIALS AND METHODS] Flap transfer was evaluated on 20 gracilis muscles, was adapted between temporal area and oral and eyelid regions. Morphological measurements were obtained. Vascular pedicle of flap was examined. Distal vessel distribution was visualized on radiography.

[RESULTS] Width of gracilis was 55.94 ± 6.83 mm. Number of distal branches of major pedicle was minimum four and maximum six. There was no correlation between number of vessels and muscle width. Appropriate length of distal muscle was cut from hilum. Vessels within sagittal sections at the distal edge of the flap were examined under an operating microscope. Uppermost(1st) part had a weak vascular network (1.70 ± 0.45). All neurovascular morphological measurements indicated suitability for anastomosis sites.

[CONCLUSION] Results showed that distal part of gracilis muscle flap in all cadavers could be split into four equal parts, each having vessels. Anatomically, modified free functional split gracilis flap design is suitable and transferable for periorbital and perioral smile reanimation.