Atlas of General Surgical Techniques (Courtney M. Townsend Jr., B. Mark Evers)

3. DEEP LOBE PAROTIDECTOMY

All branches of the upper and lower divisions of the facial nerve are systematically dissected, and the entire lateral lobe of the parotid is removed when the tumor located in the lateral lobe dictates it and in cases in which a total parotidectomy is required (deep lobe tumor, malignancy, chronic parotitis). The superficial lobe is sent as a separate specimen (Figure 4-8).

Stensen’s duct is transected at the anterior border of the gland and ligated. Care is taken not to injure the buccal branch of the nerve that runs parallel to Stensen’s duct (see Figure 4-8).

To remove the deep lobe of the parotid, the surgeon very delicately and meticulously dissects the main trunk of the facial nerve and its branches to free them from the deep lobe.

After each branch is completely freed from the deep lobe, the surgeon uses gentle retraction using a vein retractor, nerve hook, or very small vessel loops to lift the nerves, allowing blunt and sharp dissection and mobilization of the deep lobe. Excessive retraction of the nerves will result in a stretch injury (see Figure 4-8).

The gland may be dissected from the stylohyoid and stylopharyngeus muscles. During dissection of the deep lobe the following vessels may be encountered: the superficial temporal vessels, the internal maxillary artery (running deep to mandibular ramus), the occipital artery, the posterior auricular artery, and the pterygoid plexus of veins. Bleeding can be substantial, and patience must be used in identifying and controlling the bleeding vessel to avoid inadvertent injury to the nerve (Figure 4-9).

Removal of the deep lobe may be accomplished inferior to, superior to, or between facial nerve branches (see Figure 4-9).

5. CLOSING

The main trunk of the facial nerve is stimulated (0.5 mA) to prove that all branches are intact before the wound is closed. If some or all of the branches do not respond to stimulation, careful inspection to ensure anatomic integrity of nerve is performed.

The skin is closed in two layers using fast absorbing versus monofilament suture. Care is taken to accurately reapproximate the lobule.

A 10-mm Jackson-Pratt drain is placed via a separate stab incision in the postauricular area. Care is taken to avoid placement of the drain next to the nerve.

A figure-of-eight pressure dressing is placed around the neck, face, and head.

STEP 4: POSTOPERATIVE CARE

Facial nerve function is evaluated as soon as the patient is awake and cooperative.

If facial nerve paresis or paralysis is noted, steroids may be given only if the facial nerve is known to be intact. If it is possible that the main trunk or nerve branch was transected during surgery, immediate exploration and repair of nerve must be performed.

Pressure dressing is removed the next morning.

Closed suction drain is removed when output is less than 15 to 30 mL over 24 hours.

If eye closure is poor (neuropraxia, nerve sacrifice), saline drops are used multiple times per day, and Lacri-Lube and eye taping are prescribed nightly to prevent exposure keratitis.

STEP 5: PEARLS AND PITFALLS

A nerve integrity monitor and magnification (loupe or microscope) may be used to aid in facial nerve identification and preservation, particularly in reoperations and cases of chronic infection with scarring.

Overuse of the facial nerve stimulator can cause neuropraxia.

If the tumor location precludes identification of the main trunk of the facial nerve using standard techniques, the main trunk can be identified using retrograde dissection along the temporal, buccal, or marginal mandibular branch (most common) or via mastoidectomy.

Parotid specimen and/or lymph nodes are sent for intraoperative frozen section analysis if malignancy is suspected.

The posterior auricular artery or its branch can cross the main trunk of the facial nerve and cause significant bleeding and inadvertent injury to the nerve if not properly identified and ligated.

Facial paralysis or paresis can result from aggressive dissection or inadvertent injury of the nerve. Recovery of facial nerve paresis/paralysis can occur over 3 to 4 weeks if neuropraxic injury and up to 1 year if axon death has occurred.

Hematoma formation, manifested by acute postoperative pain, swelling of flap, and oozing from wound, demands reexploration and evacuation. Hematoma can cause airway compression if significant. Extreme care must be taken to avoid injury to the exposed facial nerve.

Skin flap necrosis is rare but can occur in heavy smokers and in the postauricular area when the skin flap is too thin and the skin incision is made at an acute angle.

Frey’s syndrome (gustatory sweating) is associated with sweating in the area of skin overlying the parotid bed. Most patients have this to some degree, and it is typically subclinical. It occurs because of the aberrant regrowth of parasympathetic motor fibers from the auriculotemporal nerve into the sympathetic nerve fibers controlling sweat glands. Raising thicker subcutaneous flaps may reduce its occurrence. Medical therapy includes topical scopolamine. Surgical remedies are rarely successful (dermal graft, tympanic neurectomy).

Postoperative sialocele or salivary fistula (salivary drainage from wound) is rare and can usually be successfully managed with aspiration and compression dressings. Atropine-like drugs may be beneficial.

SELECTED REFERENCES

1. Johnson JT: Parotid. In Myers EN, Carrau RL (eds): Operative Otolaryngology: Head and Neck Surgery, 1st ed. Philadelphia, Saunders, 1997, pp 504-518.

2. Olsen KD: Parotid superficial lobectomy. In Bailey BJ, Calhoun KH, Coffey AR, Neely JG: Atlas of Head & Neck Surgery—Otolaryngology. Baltimore, Lippincott-Raven, 1996, pp 2-11.

3. Lore JM, Medina J: The parotid salivary gland and management of malignant salivary gland neoplasia. In Lore JM, Medina J (eds): An Atlas of Head and Neck Surgery, 4th ed. Philadelphia, Saunders, 2005,

pp 861-891.

4. Olsen KD: Superficial parotidectomy. Oper Tech Gen Surg 2004;6:102-114.

5. Shah JP, Patel SG: Salivary glands. In Shah JP, Patel SG (eds): Head and Neck Surgery and Oncology, 3rd ed. Edinburgh, Mosby, 2003, pp 439-474.

STEP 2: PREOPERATIVE CONSIDERATIONS

Indications:

Respiratory failure with ventilator dependence

Airway obstruction: edema, trauma, tumor, hematoma

Status of cervical spine:

If status of cervical spine is in question, seek neurosurgical clearance before extending the neck.

In patients with a cervical spine injury, the neck remains in a neutral position and the head and neck are stabilized with sandbags.

If the patient has had a previous tracheotomy, the operative report is reviewed with attention to the level of the tracheotomy and the presence of anatomic abnormalities.

A vertical, rather than horizontal, skin incision is useful in the following cases: (1) redo tracheotomies, because it gives a larger area of exposure, which is helpful when dealing with scar tissue; (2) in patients whose landmarks are not easily palpated; and (3) in infants and children.

Local, awake tracheotomy should be considered in patients with laryngeal obstruction (edema, tumor) who are not in acute airway distress and who are determined to be difficult fiber-optic intubations.

“High” tracheotomies are performed in patients with laryngeal carcinoma so that maximal tracheal length can be preserved for stoma construction in the event a total laryngectomy is required for treatment.

The size of the tracheotomy tube is decided preoperatively (a size 6 cuffed tube is usually placed in a woman, and a size 8 cuffed tube is usually placed in a man). An extendedlength tracheotomy tube may be necessary in patients with large necks and should be available in the operating room before the tracheotomy is performed.

The cuff of the tracheotomy tube is tested before use.

The surgeon and anesthesiologist discuss the surgical plan preoperatively; the airway is shared by both parties.