The surgical management of facial nerve injury☆

To evaluate iatrogenic facial nerve injury in mastoidectomy and its paralysis improvement result after nerve injury management.

A retrospective review of medical records of 21 patients with iatrogenic facial nerve injury following mastoidectomy who underwent nerve injury management in a tertiary referral center.

There were nine males and 12 females, with a mean age of 40.4 ± 15.1 years. Cholesteatoma was the most common primary pathology (76.2%). Mastoidectomy was canal wall up in 8 patients and canal wall down in 13. Nerve injury was due to drilling in 10 patients and sharp tools in 11. The tympanic segment of the facial nerve was the most common injured site (50.0%). Decompression was the most common nerve injury management method (52.4%). Other injury management methods were end-to-end anastomosis (14.3%), great auricular nerve graft (23.8%), and facial-hypoglossal nerve transfer (9.5%). No statistically significant correlation was found between facial nerve function 3–6 months after injury management and the following factors: age, gender, primary pathology, type of mastoidectomy, surgeon's experience, nerve injury site, mechanism of trauma, and nerve injury management method and timing.

Regardless of the surgeon's experience or technique applied, a meticulous approach may be more valuable in decreasing the chance of iatrogenic facial nerve injury.

Facial paralysis can lead to detrimental effects on patient quality of life and impair social engagement. Accordingly, it is vital that acute injuries be triaged and managed appropriately to ensure optimal functional outcome for the patent. Here we will discuss the potential etiologies of acute facial nerve injury, particularly those that are amenable to primary repair or reconstruction with cable grafting. We will highlight options for management, the associated operative technique, and the expected recovery of function in an evidence-based fashion.

In cases where the proximal stump of the facial nerve is unavailable for repair or interposition nerve grafting, and there are intact distal facial nerve branches and viable mimetic muscles, then the masseter-to-facial (V–VII) nerve transfer can provide an effective means of smile restoration. Positive attributes of the V–VII transfer include: limited donor site morbidity, anatomic consistency, a dense population of myelinated motor nerve fibers capable of producing strong motion, synergy with the facial nerve and potential for effective cerebral adaptation yielding an effortless smile. The technique can be utilized in isolation or combined with cross face nerve grafts to further enhance spontaneity and resting tone.

Lorsque le moignon proximal du nerf facial ne peut pas contribuer à la réparation ou à la greffe nerveuse par interposition, et lorsqu’il existe des branches nerveuses faciales distales intactes ainsi que des muscles de la mimique viables, le transfert du nerf massétérin sur le nerf facial (V–VII) peut constituer une technique efficace de restauration du sourire. Parmi les aspects positifs de ce transfert figurent : morbidité réduite du site donneur, cohérence anatomique, une grande concentration de fibres nerveuses motrices myélinisées et capable de produire de forts mouvements, synergie avec le nerf facial et potentialité d’adaptation cérébrale efficace donnant lieu à un sourire prenant forme sans effort. Cette technique peut être utilisée soit isolément, soit en l’associant à des greffes nerveuses transfaciales en vue d’améliorer la spontanéité et le tonus de repos.

La paralysie faciale est connue dès l’Antiquité et mentionnée depuis Hippocrate. Au xvii^e siècle en 1687, le médecin hollandais Stalpart Van der Wiel, publia une observation détaillée. Mais, c’est Charles Bell qui en fit la description en 1821, précisant le rôle du nerf facial. La chirurgie du nerf facial commença à la fin du xix^e siècle. Trois sortes de techniques furent successivement utilisées : les anastomoses nerveuses (XI-VII Ballance 1895, XII-VII, Korte 1903), les myoplasties (Lexer 1908), les suspensions (Stein 1913). La suture directe du nerf intrapétreux fut réussie en 1927 par Bunnell et les greffes nerveuses expérimentées par Ballance et Duel en 1932. À partir de 1970, grâce aux progrès des techniques microchirurgicales, les premières greffes nerveuses transfaciales furent réalisées (Smith, Scaremella), et le premier transfert musculaire avec anastomose microvasculaire publié par Harii en 1976. Le traitement des paralysies palpébrales a été à l’origine de nombreux essais techniques à partir des années soixante : ressort palpébral (Morel Fatio 1962), fil de silicone (Arion 1972), alourdissement de la paupière par plaque d’or (Illig 1958), aimants (Muhlbauer 1973), greffes nerveuses transfaciales (Anderl 1971). À la fin du xx^e siècle, les opérateurs disposaient d’une large gamme de techniques mais des interventions anciennes rénovées restaient valables.

Facial paralysis has been a recognized condition since Antiquity, and was mentionned by Hippocratus. In the 17th century, in 1687, the Dutch physician Stalpart Van der Wiel rendered a detailed observation. It was, however, Charles Bell who, in 1821, provided the description that specified the role of the facial nerve. Facial nerve surgery began at the end of the 19th century. Three different techniques were used successively: nerve anastomosis, (XI-VII Balance 1895, XII-VII, Korte 1903), myoplasties (Lexer 1908), and suspensions (Stein 1913). Bunnell successfully accomplished the first direct facial nerve repair in the temporal bone, in 1927, and in 1932 Balance and Duel experimented with nerve grafts. Thanks to progress in microsurgical techniques, the first faciofacial anastomosis was realized in 1970 (Smith, Scaramella), and an account of the first microneurovascular muscle transfer published in 1976 by Harii. Treatment of the eyelid paralysis was at the origin of numerous operations beginning in the 1960s; including palpebral spring (Morel Fatio 1962) silicone sling (Arion 1972), upperlid loading with gold plate (Illig 1968), magnets (Muhlbauer 1973) and transfacial nerve grafts (Anderl 1973). By the end of the 20th century, surgeons had at their disposal a wide range of valid techniques for facial nerve surgery, including modernized versions of older techniques.

This chapter aims to cover the evaluation and the more common management strategies used in the rehabilitation of facial paralysis. This includes the global assessment of facial nerve palsy. Operative strategies such as reinnervation techniques—hypoglossal, masseteric, cross-facial nerve transfer—are reviewed as are static and dynamic interventions for all facial zones (brow, periocular, midface, smile and lip depressors). Chemodenervation and surgical strategies for synkinesis are also assessed.