PAROTIDECTOMY

PRESENTER: DR PRASHANTH LMODERATOR: DR R M LALITHA

CONTENTS1. INTRODUCTION2. SURGICAL ANATOMY3. TYPES OF PAROTIDECTOMY4. PREOPERATIVE EVALUATION5. SUPERFICIAL PAROTIDECTOMY6. TOTAL PAROTIDECTOMY7. EXTENDED TOTAL PAROTIDECTOMY8. COMPLICATIONS9. REFERENCES

INTRODUCTION

A parotidectomy is the surgical excision (removal) of the parotid gland, the major and largest of the salivary glands.

The procedure is most typically performed due to benign or malignant tumors.

The majority of parotid gland tumors are benign, however 20% of parotid tumors are found to be malignant.

Rule of 80’s: -80% of parotid tumors are benign -80% of parotid tumors are pleomorphic

adenomas -80% of salivary gland pleomorphic

adenomas occur in the parotid -80% of parotid pleomorphic adenomas occur

in the superficial lobe -80% of untreated pleomorphic adenomas

remain benign

SURGICAL ANATOMY

Parotid gland The paired parotid

glands are the largest of the major salivary glands

weigh, on average, 15–30 g.

Preauricular region

Boundaries The parotid duct

Parotid gland is divided by the facial nerve into

i. a superficial lobe ii. a deep lobe

An accessory parotid

gland

Superficial Muscular Aponeurotic System (SMAS)

SMAS is a fibrous network that invests the facial muscles, and connects them with the dermis.

Platysma inferiorly; Zygomatic arch superiorly Facial nerve courses deep to

the SMAS and the platysma. Parotid fascia

Facial nerve and branches

Structures within the parotid gland

External carotid artery and its branches

Veins

Lymphatics: Superficial nodes drains

auricle, anterior part of scalp, upper part of face

Deeper nodes receives lymph from external acoustic meatus, middle ear, auditory tube, nose, palate and deep parts of cheek.

Cervical lymphnodes

RELEVANT SURGICAL RELATIONS Posterior: Cartilage of external auditory

meatus; tympanic bone, mastoid process, sternocleidomastoid muscle

Deep: Styloid process, stylomandibular tunnel, parapharyngeal space, posterior belly of digastric, sternocleidomastoid muscle

Superior: Zygomatic arch, temporomandibular joint

TYPES OF PAROTIDECTOMY

Partial parotidectomy: Resection of parotid pathology with a margin of normal parotid tissue. This is the standard operation for benign pathology and low grade malignancies

Superficial parotidectomy: Resection of the entire superficial lobe of parotid and is generally used for metastases to parotid lymph nodes e.g. from skin cancers, and for high grade malignant parotid tumors.

Total parotidectomy: This involves resection of the entire parotid gland, usually with preservation of the facial nerve

Extended Total Parotidectomy: Removal of the superficial and deep parotid gland also may be extended to involve adjacent structures.

PREOPERATIVE EVALUATION A thorough history is obtained prior to

consideration for surgery. Symptoms of sensory loss, trismus and facial

weakness are worrisome for local tumor invasion by a malignant neoplasm.

The past medical history should include information regarding any prior cutaneous lesions or malignancies.

In addition, the patient should be queried about any prior radiation exposure to the head and neck including dental radiographs.

Smoking is associated with Warthin’s tumor and, therefore, should be investigated.

This tumor can also occur bilaterally, thus any history of a prior parotid tumor should be elicited.

Cranial nerve function should be examined and facial nerve function should be evaluated carefully.

Facial nerve paralysis is usually an indication of nerve invasion by a malignant tumor.

Fixation to the overlying skin, limited mobility of the mass, and associated cervical lymphadenopathy are other signs suggestive of malignancy.

FINE-NEEDLE ASPIRATION BIOPSY (FNAB) It is an accurate and useful investigation for the

diagnosis of a parotid mass. FNAB allows for improved patient selection for

surgery since it can identify conditions such as reactive lymph nodes or cysts that might mimic parotid neoplasms clinically.

The information gained by FNAB is useful for patient counseling, surgical timing and planning, and guiding the direction of preoperative consultation

RADIOLOGY Radiological investigation is not routinely

required with parotid tumors. It is recommended for surgical planning with

tumors that are large, fixed, and are associated with facial nerve involvement, trismus, and parapharyngeal space involvement.

MRI is a valuable investigation with recurrence of pleomorphic adenoma as it is often multifocal.

PREOPERATIVE CONSENT

Scar Anesthesia in the greater auricular

distribution Facial nerve weakness Facial contour Prominence of auricle Frey’s syndrome (gustatory sweating)

PREOPERATIVE CONSENT

Scar Anesthesia in the greater auricular

distribution Facial nerve weakness Facial contour Prominence of auricle Frey’s syndrome (gustatory sweating)

SUPERFICIAL PAROTIDECTOMY Superficial lobe parotidectomy describes removal

of all or a portion of the parotid gland superficial to the facial nerve.

The most common indications are:1. Benign or low grade tumor of the superficial lobe

of the parotid gland2. metastases to parotid lymph nodes from

adjacent sites of skin cancer or melanoma, or from cancer of the external auditory meatus.

3. Access to the deep lobe of the gland or other structures deep to the facial nerve.

4. Chronic inflammation of parotid gland, resistant to conservative treatment.

ANAESTHESIA

General anaesthesia Short-acting muscle relaxation for intubation

only, so that facial nerve may be stimulated and/or monitored

No perioperative antibiotics unless specifically indicated

Hyperextend the head, and turn to opposite side

Infiltrate with vasoconstrictor along planned skin incision,

Keep corner of eye and mouth exposed so as to be able to see facial movement when facial nerve mechanically or electrically stimulated.

TECHNIQUE

A modified Blair incision

An alternative incision is a modified face-lift incision.

The ipsilateral face is prepared with an antiseptic solution and the surgical field is draped with a transparent adhesive sterile drape.

Nerve electrodes are placed in the ipsilateral facial muscles and tested for electrical integrity.

The skin incision is made through the subcutaneous tissues and platysma muscle.

Greater auricular nerve.

An anterior flap is elevated superficial to the greater auricular nerve and the parotid fascia.

Anterior flap- the peripheral branches of the facial nerve.

A posterior, inferior flap- expose the tail of the parotid gland.

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.

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 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.

The gland is carefully retracted anteriorly.

This exposes the operative field for identification of the facial nerve.

The facial nerve is identified using anatomic landmarks:

1. Posterior belly of the digastric muscle

2. Mastoid tip 3. Tragal cartilage pointer 4. Tympanomastoid suture.

If the proximal segment of the facial nerve is obscured, retrograde dissection of one or more of the peripheral facial nerve branches may be necessary to identify the main trunk.

When necessary, the facial nerve can be identified in the mastoid bone by mastoidectomy and followed peripherally.

Once the facial nerve is identified, the parotid gland superficial to the facial nerve is divided carefully, preserving the integrity of the nerve.

The exact location of the facial nerve should always be determined prior to division of the gland tissue.

The facial nerve is followed peripherally, the desired portion of the gland is dissected from facial nerve branches and the specimen removed.

The facial nerve is preserved except in cases when confirmed malignancy is found invading the nerve.

In instances of facial nerve invasion by carcinoma, facial nerve resection is performed.

Proximal and distal margins of the resected nerve are examined histologically by frozen section to ensure clear surgical margins.

If the tumor involves the stylomastoid foramen, mastoidectomy is performed to identify the proximal facial nerve in the fallopian canal to achieve a clear margin.

Immediate nerve reconstruction by a nerve interposition graft is usually indicated if facial nerve resection is performed.

After the superficial portion of the gland is removed.

The wound is carefully inspected and bleeding sites are controlled with bipolar electrocautery or ligatures

The integrity of the facial nerve is confirmed visually and by electrical stimulation of the main trunk of the facial nerve and all the peripheral branches.

A neck dissection is performed for clinically positive nodes.

For the clinically negative neck, the first echelon nodes are inspected.

Enlarged or suspicious nodes are examined and a neck dissection is performed if metastatic disease is confirmed by frozen section.

The wound is irrigated, realigned, and closed in layers over a closed-suction drain.

The drain is usually removed on the first postoperative day and the skin sutures are removed within one week.

Adjuvant radiation therapy is recommended for select malignancies including

i. metastatic cutaneous squamous cell carcinoma

ii. high-grade and advanced parotid malignancies

TOTAL PAROTIDECTOMY

Total parotidectomy is the total removal of the superficial and deep parotid gland.

The operation may involve sparing or sacrifice of the facial nerve branches or trunk depending on tumor extent to the nerve.

INDICATIONS:1. Metastasis to a superficial parotid node

from a primary parotid tumor or an extraparotid malignancy

2. Parotid malignancy that indicates metastasis by involvement of cervical lymph nodes

3. High-grade parotid malignancy with a high risk of metastasis.

4. Primary parotid malignancies originating in the deep lobe and for primary malignancies that extend outside the parotid gland.

5. Multifocal tumors, such as oncocytomas, to ensure complete removal

EXTENDED TOTAL PAROTIDECTOMY

Removal of the superficial and deep parotid gland also may be extended to involve adjacent structures such as the overlying skin, the underlying mandible, the temporal bone and external auditory canal, or the deep musculature of the parapharyngeal space.

These extensions are dictated by tumor growth and behavior.

SURGICAL TECHNIQUE:

1. Preparation2. Incisions and flap elevation3. Deeper dissection 4. Facial nerve mobilisation

5. Removal of superficial gland 6. Deep parotidectomy7. Total Parotidectomy with Facial Nerve

Sacrifice8. Resection of Adjacent Structures and

Reconstruction

PREPARATION The operation is performed with the patient

under general endotracheal anesthesia. Endotracheal tube is positioned and taped to

the oral commissure and cheek opposite to the lesion.

The patient is placed in a 45° reverse-trendelenburg position or lounge-chair position with the head higher than the heart.

The head is turned to the opposite side of the lesion, and the neck is extended by placement of a rolled sheet under the shoulders.

The patient is prepared by sterile scrub and draped so that the ear, lateral corner of the ipsilateral eye, ipsilateral oral commissure, and entire ipsilateral neck are visible in the field.

If facial nerve monitoring is to be used, the nerve monitor is placed in the orbicularis oris and orbicularis oculi muscles to ensure upper and lower division monitoring.

The surgeon stands on the side of the patient ipsilateral to the gland to be dissected, the assistant stands at the head and opposite the surgeon, and the scrub technician stands on the side of the surgeon.

INCISIONS AND FLAP ELEVATION

INCISIONS AND FLAP ELEVATION

INCISIONS AND FLAP ELEVATION

DEEPER DISSECTION

FACIAL NERVE MOBILIZATION

A small curved clamp is oriented perpendicular to the anticipated direction of the facial trunk to elevate tissues layer by layer.

Scissors are never used for dissection down to the nerve, and no tissue is cut in this area until the nerve is seen.

Blunt dissection proceeds posterior to anterior until the surgeon identifies the nerve as a white cord 2–3 mm wide.

REMOVAL OF THE SUPERFICIAL GLAND

The gland is separated at its edge, the temporal or marginal branches being followed to the periphery.

The thickest fascia is encountered posterosuperiorly; this must be divided sharply or the surgeon will make tunnels into the gland along the nerve.

Posteriorly- branches of the superficial temporal vein may be encountered.

Vessels directly adjacent to the nerve branches should not be cauterized until the superficial lobe is completely mobilized.

After following a nerve branch to its peripheral emergence from the parotid gland, the surgeon returns to a proximal position along that nerve and searches for another branch to follow.

Dissection progresses from posterior to anterior and either superiorly or inferiorly until the superficial gland has been completely separated from the facial nerve and the deep parotid gland.

At this point, the surgeon should have a clear impression of the relationship of the tumor to the facial nerve, superficial gland, deep gland, and surrounding structures.

It may be necessary to dissect along the tumor capsule to separate it from the deep gland and facial nerve.

Careful retraction and meticulous dissection can prevent rupture of the tumor capsule, which is often pivotal in the prevention of recurrence.

The gland is now left attached to only the parotid duct.

The surgeon inspects this area to ensure that no buccal branches are adherent to the duct.

The duct is divided and ligated, and the specimen is sent for examination by the pathologist.

The wound should now be irrigated and the field inspected for bleeding vessels, which are ligated.

DEEP PAROTIDECTOMY

The gland is completely freed from attachment to any adjacent structures and sent for frozen-section pathologic examination.

Small vessels around the deep gland adjacent to the mastoid and trunk can be cauterized using the bipolar forceps.

The wound is irrigated, and meticulous hemostasis is achieved.

If necessary, the incision can be extended for neck dissection at this time.

At the conclusion of the operation, a suction drain is placed in the wound through a separate stab incision in the postauricular skin and sewn into place.

The wound is closed with interrupted absorbable sutures

Dressing or antibiotic ointment can be applied.

Patient is awakened and extubated.

TOTAL PAROTIDECTOMYWITH FACIAL NERVE SACRIFICE

If facial nerve function is normal preoperatively, even in patients with malignancy, then the nerve can be preserved with careful dissection of the tumor off the nerve sheath.

If the nerve is paretic or fully paralyzed preoperatively, then it is involved with tumor and is normally resected during tumor resection.

Nerve that is clearly invaded by high-grade malignant tumor should be resected with the specimen to negative proximal and distal margins.

This may necessitate sacrificing peripheral branches, divisions, or even the main trunk of the facial nerve.

Intraoperatively, a nerve that is infiltrated with tumor will appear swollen and usually darker than the normal glistening white appearance of normal facial nerve.

After negative proximal and distal facial nerve margins are obtained, the nerve is reconstructed with primary neurorraphy or grafting.

Mastoidectomy and nerve mobilization may be necessary to attain proper length of the facial nerve for tension-free anastomosis.

Appropriate grafts include: i. ipsilateral greater auricular nerve if it is not

involved with tumor ii. ipsilateral sural nerve graft. Peripheral branches can be graftedi. proximal facial nerveii. ipsilateral hypoglossal nerve

RESECTION OF ADJACENT STRUCTURES

AND RECONSTRUCTION The operation may be extended to involve resection

of adjacent structures that are involved with tumor. It may include i. lateral or subtotal temporal bone resection, ii. partial mandibular resection, iii. resection of the overlying skin,iv. resection of portions or all of the auditory canal, and v. resection of surrounding musculature.

Options for reconstruction include i. primary closure,ii. dermal fat grafting, iii. muscle transposition with loco regional flaps of

the sternocleidomastoid or pectoralis muscles,iv. micro vascular cutaneous, musculocutaneous,

and innervated muscular flaps. Again, the reconstruction will be guided by the

functional and aesthetic goals of the surgeon and patient.

COMPLICATIONS1. Hematoma

2. Infection

3. Facial nerve palsy

4. Salivary fistula

5. Gustatory sweating/ Frey’s syndrome

6. Cosmetic deformity

Inadequate hemostasis before closure.

Suction drain reduces possibility of postoperative hematoma.

Treatment: i. Evacuation of hematomaii. Control of bleeding pointsiii. Reinsertion of suction drain

and closure.

HEMATOMA

Infection is rare Some tumors presents with obstructive

symptoms if infected. Prophylactic antibiotics are given if operating

on an infected gland.

INFECTION

Temporary or permanent Partial or total Neuropraxia- due to

stretching of the nerve. If the nerve is intact at

the end of procedure- recovery within few weeks.

FACIAL NERVE PALSY

If the palsy is severe and recovery is prolonged- transcutaneous nerve stimulation of facial muscles.

Problems with eye closure- i. protective glasses or tape the eyelid to

prevent exposure keratitis.ii. Temporary tarsorrhaphy or paralysis of

eyelid elevator with botulinum toxin to allow closure of upper eyelid.

When palsy is due to partial or total loss of facial nerve:

i. reconstruction ii. rehabilitation of face

Presents after suture removal at the suture line and posterior to ear lobule.

Pressure dressing. Drains Anticholinergic drugs- to

reduce salivary secretion

SALIVARY FISTULA

Auriculotemporal syndrome.

60% of all parotidectomy cases.

Discomfort, localized facial sweating and flushing during mastication.

FREY’S SYNDROME

Due to parasympathetic and sympathetic secretomotor stimuli misdirected to cholinergic receptors of sweat glands during healing after parotid surgery.

The iodine test administered by applying an alcohol–iodine–oil solution (3 g iodine, 20 mL castor oil, and 200 mL absolute alcohol) described by Laage-Hellman

The solution was applied on the lateral portion of the face that had been surgically treated and the upper region of the neck.

The solution was allowed to dry and was covered lightly with starch powder.

The patients received lemon candy for a gustatory stimuli for 10 minutes.

Discoloration of the starch iodine mixture was interpreted as a positive finding for Frey’s syndrome

There is no effective treatment, but various options are described:

i. Injection of Botulinum Toxinii. Surgical transection of the nerve fibersiii. Application of an ointment containing

an anticholinergic drug such as scopolamine

Incision mark Sunken cheek due to

loss of parotid gland and fat.

Rotation of sternomastoid muscle flap at the time of surgery.

Free flaps.

COSMETIC DEFORMITY

REFERENCES1. Salivary Gland Disorders: Eugene N. Myers, Robert

L. Ferris; Springer.2. Parotidectomy : Johan Fagan : Open Access Atlas Of

Otolaryngology, Head & Neck Operative Surgery3. Maxillofacial Surgery: Second Edition; Volume 1:

Peter Wardbooth.4. Operative Maxillofacial Surgery; John D Langdon

and Mohan F Patel.5. Internet

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