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Failures in the past have been related to loss of muscle volume due to vascular compromise and poor muscle orientation and bulk. Secondary revisions of the muscle may be necessary to reduce the bulk of muscle and to redirect the angle of pull and degree of tension. Because the blood and nerve supply are on the deep side of the muscle, the secondary revisions can be accomplished without fear of injuring the neurovascular input.
Further experimental and clinical work is needed in the field of muscle and nerve physiology to improve the above two-stage operation. To date, however, this approach can restore spontaneous animation, often to a surprisingly normal degree, particularly in young individuals. Some patients develop the ability to control the paralyzed side selectively without moving the normal side, indicating selective neuromuscular control of innervation through the crossfacial graft.
PLATE XXII-1
A. The superficial anatomy of the facial nerve is shown. In this instance,
dissection is performed on the normal side to isolate the entire marginal
mandibular branch and a large branch to the upper lip. These will be anastomosed
to the crossfacial sural nerve graft. Exposure can best be obtained through
an extended face-lift incision, carrying the incision down below the angle
of the mandible anteriorly, with a Risden type of parotid dissection and
incision. This dissection is performed at the anterior border of the parotid
in the fat of the cheek.
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B. A subcutaneous tunnel is created across the lower lip to carry
the long sural nerve graft. The nasolabial incision greatly facilitates
this passage. One strand of the nerve is used, preferably from the proximal
portion where there are multiple fascicles. The nerve is placed in an
antegrade fashion, anastomosing the distal end to the donor nerves on
the normal side.
C. The sural nerve has been split into two bundles, which are anastomosed
under high magnification with 11-0 microsutures to the isolated donor
branches of the normal nerve.
PLATE XXII-2
A. The crossfacial nerve on the paralyzed side is brought out to the
preauricular region and marked with a hemoclip and securing suture in
the pretragal area. A temporalis transfer to the upper and lower eyelids
is performed. A McLaughlin temporalis transfer is then done intraorally
and extraorally using fascia from the lateral head of the gastrocnemius
muscle in the sural-nerve donor area.
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