Indications for facial reanimation using innervated muscle flaps relate to the extent of the paralysis, the age of the patient, and the patient’s needs and desires. A significant degree of facial paralysis, with inability to elevate the commissure and upper lip, warrants consideration for reconstruction. Although possible in older age groups, I believe that reinnervation of a transferred muscle, particularly through cross-face nerve grafts, begins to lose its effectiveness in the sixth and seventh decades of life. Some patients require a rapid, static, alteration and would not benefit from the time-consuming cross-face nerve graft/free muscle transfer. Other patients may be quite well adjusted to their condition and not wish to undergo any surgical reconstruction. Thus, it is crucial to present what is possible and what is not possible to the patient. Elevation of the commissure and upper lip is usually an attainable goal (4). The direction of movement can be adjusted to match the normal side; however, perfect symmetry is never achieved. This procedure addresses only elevation of the commissure and upper lip and does not reconstruct the multitude of other fine movements of the face associated with smiling.

There are three situations that can be addressed by muscle transfer in facial paralysis, depending on the availability of a motor nerve (5). If the stump of the ipsilateral facial nerve is available, as may follow tumor excision, this stump can be used
directly to innervate the transferred gracilis. The second situation is a unilateral facial paralysis where there is no ipsilateral facial nerve; for example, a case following acoustic neuroma surgery where the seventh nerve is nonfunctional at the intracranial level. In this case, a portion of nerve activity from the normal side can be transferred across the face through a cross-face nerve graft. This involves a preauricular incision with dissection of the normal nerve. The specific branches that go to the zygomatics major and minor are identified, and a portion of these can be taken for anastomosis to the nerve graft. The sural nerve graft is tunneled across the face through incisions in the nasal floor and preauricular region; after nerve repair on the normal side, it is banked in the preauricular area of the paralyzed side. One year later, this banked stump of the sural nerve can be used to innervate the transferred partial gracilis.

A third situation is when there is no facial nerve available bilaterally, as occurs in congenital conditions such as Mobius syndrome and also occasionally in patients with bilateral acoustic neuromata. In this situation, a partial gracilis transfer can be used to provide elevation of the commissure and upper lip, but it must be innervated by a regional motor nerve. Available motor nerves include the fifth, the eleventh, and the twelfth. I have found the motor branch to the masseter (V) to be extremely useful in this situation.

The advantages of the partial gracilis are numerous. The neurovascular pedicle is reliable and the flap can be easily harvested. The partial gracilis can be specifically designed and sculpted to meet specific requirements for variability of length and width. The bulkiness of the transfer is minimized by using only a partial segment of the muscle. Finally, there is virtually no donor-site morbidity except for the scar in the upper medial portion of the thigh and minimal early postoperative discomfort.