6.3.8: 8. Facial Nerve in Parotidectomy
- Page ID
- 18314
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Always attempt to preserve the nerve: If functioning preoperatively, one should aim to have a functioning nerve postoperatively
Intraoperative facial nerve monitoring
- Reduces immediate postoperative weakness, but does not affect permanent facial nerve weakness (Sood AJ, et al. Facial nerve monitoring during parotidectomy: a systematic review and meta-analysis. Otolaryngol Head Neck Surg. 2015) Apr;152(4):631-7)
- Not a substitute for knowledge of surgical anatomy of facial nerve
- Not required for routine parotidectomy
- Advisable for known malignant tumours requiring total parotidectomy, revision surgery or large tumours
Benign salivary tumours
- Displace, but do not invade nerve
- Nerve can always be dissected / peeled off tumours
Malignant tumours
- Functioning, normal looking nerve may be peeled off tumour, and microscopic residuum treated with postoperative radiotherapy
- If nerve is invaded/encased by tumour
- Confirm malignancy on frozen section
- Resect involved segment until free margins on frozen section (perineural spread can extend many centimetres beyond normal looking nerve)
- Be prepared to dissect the mastoid segment of the nerve if positive margin at stylomastoid foramen
- Immediately graft resected nerve, unless a small midface branch (cross-innervation in midfacial branches)
No postoperative radiotherapy or frozen section with known malignancy adherent to, or invading nerve
- May need to be surgically more aggressive
- Reservations about peeling nerve off tumour – but resect nerve only when the remainder of the operation is likely to achieve clear margins
- Resect nerve at least 1cm beyond obvious tumour