Superficial Parotidectomy
Superficial parotidectomy is performed under general anesthesia.. After the induction of general anesthesia, the endotracheal tube is positioned in the contralateral oral cavity and secured by tape on the contralateral face only.
A modified Blair incision is planned in a preauricular crease coursing around the ear lobule and then into an upper neck crease.
Methylene blue can be used to mark points along the proposed incision, which facilitates proper wound alignment and closure. The ipsilateral face is prepared with an antiseptic solution and the surgical field is draped with a transparent adhesive sterile drape to allow visualization of facial motion.
The skin incision is made with a scalpel and carried down through the subcutaneous tissues and platysma muscle. Care is taken to avoid division of the greater auricular nerve. An anterior flap is elevated superficial to the greater auricular nerve and the parotidfascia. Elevation of a thick flap is desirable to reduce the occurrence of Frey’s syndrome while carefully avoiding violation of any neoplasm at the surface of the gland. As the flap is elevated toward the anterior aspect of the gland, the peripheral branches of the facial nerve are carefully avoided. A posterior, inferior flap is also elevated to expose the tail of the parotid gland. After elevation, the flaps are retracted with silk sutures or selfretaining hooks.
The tail of the parotid gland is dissected off of the sternocleidomastoid muscle by dissecting deep to the posterior branch of the greater auricular nerve, if preservation of this nerve is feasible based on tumor location. Next, the posterior belly of the digastric muscle is exposed with further elevation of the tail of the parotid gland. The posterior belly of the digastric muscle serves as a landmark for the facial nerve. During elevation of the tail of the parotid, the integrity of the posterior facial vein also is preserved if possible. The facial nerve usually courses superficial to this vessel and division of this structure can contribute to increased venous bleeding during dissection of the gland. Occasionally some or all of the branches of the facial nerve will be found deep to the vein.
The preauricular space is opened by division of the attachments of the parotid gland to the cartilaginous external auditory canal with blunt and sharp dissection. This plane of dissection exposes the tragal cartilage pointer, which serves as another landmark for the facial nerve.A wide plane of dissection from the zygoma to the digastric muscle is created to facilitate exposure of the facial nerve. Hemostasis is assured with bipolar electrocautery as indicated.
The gland is carefully retracted anteriorly. This exposes the operative field for identification of the facial nerve. Care must be taken to avoid pressure or traction injury of the facial nerve during retraction of the gland.
The facial nerve is identified using anatomic landmarks, which include the posterior belly of the digastric muscle, the mastoid tip, the tragal cartilage pointer, and the tympanomastoid suture.
Once the facial nerve is identified, the parotid gland superficial to the facial nerve is divided carefully, preserving the integrity of the nerve (an angled ratchetless dissecting clamp) is useful for dissection of the proximal facial nerve. The dissector is passed along the facial nerve, lifted, and then gently spread. The gland superficial to the exposed segment of the facial nerve is then carefully divided. The exact location of the facial nerve should always be determined prior to division of the gland tissue. Anatomic distortion by a neoplasm or operative manipulation must be considered.
Various instruments are acceptable for the division of parotid gland tissue and include a standard scalpel.Complete hemostasis is necessary to maintain a clear operative field relative to the facial nerve.
After the superficial portion of the gland is removed,the wound is carefully inspected and bleeding sites are controlled with bipolar electrocautery or ligatures.
