parotid surgeries

Surgery of the Parotid gland

Superficial parotidectomy

Indications for lateral lobectomy(superficial parotidectomy)

• Benign parotid tumours• Low grade malignant tumours of small size,• Refractory sialolithiasis, • sialoadenitis (chronic parotitis), and • chronic sialorrhea;

Other indications

• As part of lymph node dissection for other head and neck primary tumors, primarily cutaneous malignancies of the face and scalp

The anatomic landmarks

◆ The mastoid process with the insertion of the sternocleidomastoid (SCM) muscle

◆ Posterior belly of the digastric muscle ◆ Tragal pointer ◆ Temporoparotid fascia ◆ Tympanomastoid fissure ◆ Styloid process

• Pre-operative patient counselling after work up

Patient positioning

• The patient is placed supine, with the head at the top of the table and the ipsilateral shoulder as close to the edge of the operating table as possible.

• A shoulder roll is used to extend the neck, and the head is supported with a foam rubber doughnut-shaped ring

• Local anaesthesia with 1 in 100000 adrenaline can be used.

Incision• Cervicomastoidfacial incision(CMFI)

Given by Blair in 1912 and modified by Bailey in 1941

• Modified rhytidectomy

• The incision is made in a relaxed preauricular

skin crease, curves around the lobule toward

the mastoid tip and then anteriorly along a

natural skin crease, curving approximately 2

finger breadths below the angle of mandible

• The ear lobule is retracted posteriorly using a 2-0 silk suture to visualize the mastoid tip and cartilaginous ear canal.

Two techniques of raising skin flaps

1)Flap over the periparotid fasciaAdv: less bleeding

2)Flap under the periparotid fascia (Adv: fascia acts as a barrier ,avoids Frey syndrome)

Approach for dissection

• Antegrade approach• Retrograde approach

• The anterior skin flap is raised sharply in a supra platysmal plane, above the parotid fascia, to the anterior border of gland.

• The subcutaneous fat is elevated with the skin flap.

• The posterior skin flap is then elevated, exposing the anterior border of the SCM muscle and the mastoid process.

• Dissetion begins in the plane deep to the tail

of the parotid.

• The fascia along the anterior border of the

SCM muscle is incised, exposing the muscle

toward the level of the mastoid process.

• Electrocautery can be used in this dissection

• The great auricular nerve and external

jugular vein are identified at this time.

• If the nerve has multiple branches, the

posterior branch is preserved to maintain

sensation to the external ear.

• As the dissection proceeds anteriorly, the tail of the parotid is dissected from the SCM muscle and mastoid process, and the posterior belly of the digastric muscle is exposed.

• The gland is retracted using an Allis clamp or hemostats

• Separation of parotid tissue from

external auditory canal

• Identification of tragal cartilage( tragal

pointer) with the blunt dissection

• Hemostasis is crucial identify facial nerve

clearly

Landmarks to identify facial nerve• approximately 1 cm deep to the tip of tragal

pointer (anterior and inferior), • 6 to 8 mm below the end of the

tympanomastoid fissure (groove palpated separating the mastoid tip from the tympanic portion of the temporal bone), and

• just above and on the same plane as the attachment of the digastric muscle in the digastric groove.

• Exposure of superior part of posterior belly

of digastric

• Identification of facial nerve trunk

• Use of nerve stimulator

• A curved hemostat or scissors, with tips facing

upward, is used to spread the tissue

immediately superficial to the nerve, keeping

the nerve under direct vision at all times.

• The main trunk is dissected anteriorly.

• The upper (zygomaticotemporal) and lower

(cervicofacial) divisions are identified

• Dissection of individual facial nerve branches

• The tissue is cut in a horizontal plane parallel to the nerve.

• Once a nerve branch is completely exposed, the surgeon again returns to the major division and next branch in sequence is exposed.

DEEP LOBE PAROTIDECTOMY• Separation of superficial lobe• Exposure of all the branches of the facial nerve• Stensen’s duct dissection• Meticulous separation of facial nerve branches

from the deep lobe• Gentle retraction of nerves and vessels

• The gland may be dissected from the stylohyoid and stylopharyngeus muscles

Vessels 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.

• Extention of cervical incision more anteriorly may be required for dissection of retromandibular gland.

• In rare instances, retromandibular deep parotid tumors are too large or too inaccessible for transcervical removal.

• incision is extended anteriorly over the mentum

and a paramedian mandibulotomy is performed.

Removal of masseter:• Partial • TotalFrozen section to confirm negative margins

Radical Parotidectomy

• resection of overlying skin, adjacent mandible

and soft tissue, temporal bone, and a portion of

the adjacent external ear.

• free tissue transfer may be necessary for repair.

• Facial n.is invariably sacrificed

FACIAL PALSY

• most frequent early complication of parotid gland surgery.

• Neurapraxia(temporary paresis)Resolves spontaneously 3-4wks

• Permanent paralysisMay be more than a year

• Reassurance • Eye protection moist eye dropsTarsorrhaphyBotox injection for artificial ptosis

HYPOESTHESIA OF GREATER AURICULAR NERVE

• The area of numbness will improve within one year of the operation but a small area of skin may remain anaesthetized.

• Preserve the posterior branch of greater auricular nerve

AMPUTATION NEUROMA• greater auricular nerve

• Managed by:simple excision

COSMETIC PROBLEMS

• The “surgical depression” caused by removal of the parotid gland is most noticeable

• SCM interposition• dermal-fat interposition grafts • temporo-parietal fascia flaps• free tissue transfer

Frey’s syndrome(gustatory sweating)

- Sweating, redness and warmth in the preauricular region while eating

.

• aberrant regeneration of sectioned parasympathetic secretomotor fibres of the auriculotemporal nerve with inappropriate innervation of the cutaneous facial sweat glands that are normally innervated by sympathetic cholinergic fibres

DiagnosisMinor’s test (iodine test)

Iodine applied over affected areaDry starch applied over itTurns blue in the presence of sweat.

Surgical treatment for prevention • Sternocleidomastoid transfer and • dermis-fat grafts and the• use of various materials, as interpositional

barriers such as temporalis fascia flap

Management of established Frey’s syndrome

- Antiperspirants- Anticholinergic lotion- Denervation by tympanic neurectomy

-Cervical sympathectomy,

- Injection of botulinum toxin into the affected skin.

• local injection of botulinum toxin (BTX)• chemical denervation is effective both for

striated muscle and eccrine glands

Other complications of parotidectomy

• Haemorrhage or haematoma• Infection and Wound seroma• Trismus• Skin flap necrosis

Parotid salivary fistula

• is a relatively common complication after parotidectomy.

• Salivary fistula or sialocele occurs if the resected edge of the remaining salivary gland leaks saliva and drains through the wound or collects beneath the flap (sialocele).

• Flow through the fistula increases during meals, particularly during mastication

Management

• Amylase level to confirm• Initial management is conservative• reduce oral intake by means of enteral or

parenteral feeding. • Repeated needle aspiration and pressure

dressing are carried• SOS drain placement

• Fistulas and sialocoeles are managed with botulinum toxin injection after conventional conservative management techniques fail.

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