The surgical anatomy of the parotid fascia.

UNLABELLED: Currently, there are no reports in the literature of the parotid fascia suggesting that this structure is crucial to the identification of the facial nerve trunk (FNT). Traditional surgical and anatomical descriptions of this fascia report it as a collection of connective tissue large enough to be described by the unaided eye. This study was performed to investigate the composition and limit of the fascia surrounding the parotid gland. An appreciation of these on safe and effective parotid surgery was also considered. HISTO-ANATOMICAL STUDY: Microsurgical step-by-step dissection was performed on 18 adult cadavers (n=36) to define the composition, arrangement, and attachment of the parotid fascia. Samples were subjected to the Masson Trichrome Technique (1990). CLINICAL STUDY: A total of 18 patients presented for parotidectomy. Eight patients had a pleomorphic adenoma and ten had lympho-epithelial disease of the parotid gland. Boundaries of parotid fascia were posteriorly-mastoid process, anteriorly--ramus of mandible, superiorly--cartilage of external acoustic meatus, and inferiorly-imaginary line joining tip of mastoid process to ramus of mandible. These landmarks formed a quadrangular space. HISTO-ANATOMICAL STUDY (N=36): Parotid fascia formed a fibrous meshwork over the gland. In the upper two-thirds, fascia was thick and strong; in the lower one-third, fascia was thin. Soft tissue arrangement (from superficial to deep): dermis, subcutaneous fat, superficial cervical fascia, deep cervical fascia. CLINICAL STUDY (N=18): The technique described was applied consistently in all patients. Mean time for localization of FNT was 11 min (range 7-18 min). In two patients (both with an underlying inflammatory disorder of the parotid gland), a transient facial nerve palsy developed postoperatively. In both patients, this settled within 7 weeks of operation. The true surgical potential of the parotid fascia during parotidectomy has been reported.