The Importance of the Transverse Facial Artery As Landmark, in the Identification of the Zygomatic Branch of the Facial Nerve.

Since our initial case report in 2004 describing the “masseteric-facial” anastomosis as baby sitter, I had concerns going back to the an already operated area to perform the second stage (nerve anastomosis between the stump of the cross-face nerve graft and that of a distal Zygomatic  branch). 

In the next 3 patients we operated on, we performed a retrograde dissection of the facial nerve in the parotid gland in order to perform a more proximal anastomosis (temporal division of facial nerve) with two purposes: To  gain orbicularis oculli movement, to leave the soft tissue scarring  proximal far from the site where the second anastomosis would be performed. But we obtained unacceptable outcomes due to mass movements. 

Our goal today is to bring new axons to facial branches innervating the zygomatic muscles (to restore smiling) and orbicularis oculii of the lower eyelid (to improve lower lid laxity). For the upper lid we use (in case it is needed) a gold weight.

Identifying the facial nerve branches innervating those muscles is easy in the healthy nerve because we can use nerve stimulation, but in the nonfunctional nerve we would need to follow distally the nerves to find out their target muscle , which would create scar tissue increasing the difficulty of the second stage. Minimal dissection is the key when we are planning to perform a second stage.

Performing cross facial nerve grafts from the healthy nerve using nerve stimulation I have learned  that there is a close relationship between the transverse facial artery and the branches of the facial nerve to the zygomatic muscles and lower eyelid. 

 Since  2009 I have standardized the technique, performing a minimal dissection 1 cm ahead the anterior border of the parotid gland using the transverse facial artery as landmark to choose the facial nerve branches that will receive axons from the masseter nerve.

Material and Methods: In this paper we retrospectively review the surgical outcomes using this technique in 35 patients operated from 2009 to 2017. Ten patients (60 years and older) received just the masseter to facial nerve transfer and 25 patients (59 years and younger) masseter to Facial and cross facial nerve grafts. 

Results: Strong movement of the oral comissure elevators was obtained in all 35 patients. Improvement in the lower eyelid laxity was found in 28 patients . 

14 out of the 25 patients  scheduled for a second procedure decided to not undergo that additional procedure. 

4 of the 10 patients with just masseter to facial transfer wished to have a second procedure to obtain an involuntary movement (cross facial nerve graft). 

Lateral tarsorrhaphy was performed in 28 patients during the first stage. 

A graft of palmaris longus as lower eyelid sling was performed in 3 patients. 

An upper eyelid gold weight was placed in 10 of the 35 patients.

Conclusion: Consistent good outcomes restoring smiling movement in patients with facial paralysis were achieved using the Masseteric to Zygomatic nerve transfer using the transverse facial artery as landmark to choose the recipient nerve.