An Improved and Simplified Approach to Identify the Facial Nerve During Parotid Surgery.

Precise identification and preservation of the facial nerve is mandatory to avoid dysfunction of the facial nerve during parotidectomy. In this article, the authors are introducing a new landmark to identify the facial nerve for parotidectomy that is more protective for the facial nerve. The authors use a simple approach to predict the position of facial nerve main trunk intraoperatively without geometric calculations and a lot of landmarks. An imaginary almost 2 cm line is drawn between mastoid tip inferiorly and bony-cartilaginous junction of the external auditory canal superiorly. The main trunk of the facial nerve can be visualized at the midpoint of this line. The authors have been using this landmark successfully for the last 10 years, without any functional deficit of the parotid nerve. Identifying the facial nerve at the trunk level by this landmark renders following the branches forward in the glandular parenchyma less complicated.

A new landmark for the identification of the facial nerve during parotid surgery: A cadaver study.

OBJECTIVE: Precise knowledge of facial nerve anatomy is crucial for parotid surgery. Although several surgical landmarks to identify the facial nerve have been described in literature, their position is variable, inconsistent, and difficult to follow in some cases. The purpose of this study was to prove that the facial nerve trunk (FNT) is located midway between the mastoid tip (MT) and osteocartilaginous junction of the external auditory canal (EAC). METHODS: A prospective study of 7 frozen cadaver specimens, of which 13 facial sides were dissected. The distances between the osteocartilaginous junction and the MT, between the FNT and the MT, and between the FNT and the osteocartilaginous junction were recorded, respectively. RESULTS: The distance between the osteocartilaginous junction and the MT ranged from 17 to 21 mm, with a mean of 19.5 mm (SD = ±1.19). The mean distances between the osteocartilaginous junction and the FNT and between the MT and the FNT were 9.2 mm (±1.58) and 10.3 mm (±1.79), respectively. CONCLUSION: The FNT was consistently located close to the midpoint between mastoid tip inferiorly and bony-cartilaginous junction of the EAC superiorly. LEVEL OF EVIDENCE: NA.