anatomy of parotid with different incision designs of parotidectomies and step by step dissection

1. PAROTIDECTOMY
BY- Dr. Shalini Singh
PG OMFS

2. CONTENTS
1. INTRODUCTION
2. SURGICAL ANATOMY
3. TYPES OF PAROTIDECTOMIES
4. PREOPERATIVE EVALUATION
5. SUPERFICIAL PAROTIDECTOMY
6. TOTAL PAROTIDECTOMY
7. EXTENDED TOTAL PAROTIDECTOMY
8. COMPLICATIONS
9. REFERENCES

3. 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.

4. 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

5. SURGICAL ANATOMY

6. • Boundaries
• The parotid duct

7. Relations

8. • Parotid gland is
divided by the facial
nerve into
i. a superficial lobe
ii. a deep lobe

9. • An accessory parotid
gland

10. 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

11. Structures within the parotid gland
• Facial nerve and branches

12. Classified by Davis et al(1956)

13. Katz & Catalano
classification:
1. Type I (25%)
2. Type II (14%)
3. Type III(44%)
4. Type IV(14%)
5. Type V(3%)

14. • External carotid artery and its branches

15. • Veins

16. 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

17. Types of parotidectomies
• Partial superficial parotidectomy
• Functional superficial parotidectomy
• Superficial parotidectomy with preservation of facial nerve
• Total parotidectomy with preservation of facial nerve
• Radical parotidectomy with or without neck dissection
• Parotidomandibulectomy
• temporomandibulectomy

18. 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.

19. • 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.

20. • 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.

21. Investigations
• Fine needle aspiration biopsy
• Radiology

22. Preoperative consent
• Scar
• Anesthesia in the greater auricular distribution
• Facial nerve weakness
• Facial contour
• Prominence of auricle
• Frey’s syndrome

23. Superficial Parotidectomy
Indications are:
1. Benign or low grade tumor of the superficial lobe of the parotid
gland
2. 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.

24. Anaesthesia
• General anaesthesia
• 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.

25. Incision designs

26. technique
• A modified Blair
incision
• An alternative incision
is a modified face-lift
incision.

27. • 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.

29. • The skin incision is
made through the
subcutaneous tissues
and platysma muscle.
• Greater auricular
nerve.

30. • 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.

31. • 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.

32. • 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.

33. • 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.

34. • 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.

35. • 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.

36. • 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.

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

38. • 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.

39. • 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.

40. • After the superficial
portion of the gland is
removed.
• The wound is carefully
inspected and bleeding
sites are controlled with
bipolar electrocautery or
ligatures

41. • 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.

42. • 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.

43. • 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.

44. • Adjuvant radiation therapy is recommended for select
malignancies including
i. metastatic cutaneous squamous cell carcinoma
ii. high-grade and advanced parotid malignancies

45. 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.

46. • 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

47. 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.

48. • SURGICAL TECHNIQUE:
1. Preparation
2. Incisions and flap elevation
3. Deeper dissection
4. Facial nerve mobilisation

49. 5. Removal of superficial gland
6. Deep parotidectomy
7. Total Parotidectomy with Facial Nerve Sacrifice
8. Resection of Adjacent Structures and Reconstruction

50. 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.

51. • 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.

52. • 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.

53. INCISIONS AND FLAP ELEVATION

54. INCISIONS AND FLAP ELEVATION

55. INCISIONS AND FLAP ELEVATION

58. DEEPER DISSECTION

61. Facial Nerve Mobilization

63. • 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.

65. • 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.

66. Deep Parotidectomy

69. • 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.

70. • 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.

71. Total Parotidectomy
with 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.

72. • 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.

73. • 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.

74. • Appropriate grafts include:
i. ipsilateral greater auricular nerve if it is not involved with
tumor
ii. ipsilateral sural nerve graft.
• Peripheral branches can be grafted
i. proximal facial nerve
ii. ipsilateral hypoglossal nerve

75. 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.

76. • 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.

77. complications
1. Hematoma
2. Infection
3. Facial nerve palsy
4. Salivary fistula
5. Gustatory sweating/ Frey’s syndrome
6. Cosmetic deformity

78. • Inadequate hemostasis before
closure.
• Suction drain reduces possibility of
postoperative hematoma.
• Treatment:
i. Evacuation of hematoma
ii. Control of bleeding points
iii. Reinsertion of suction drain and
closure.
HEMATOMA

79. • Infection is rare
• Some tumors presents with obstructive
symptoms if infected.
• Prophylactic antibiotics are given if operating on
an infected gland.
INFECTION

80. • 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

81. • 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.

82. • When palsy is due to partial or total loss of facial nerve:
i. reconstruction
ii. rehabilitation of face

83. • Presents after suture
removal at the suture
line and posterior to ear
lobule.
• Pressure dressing.
• Drains
• Anticholinergic drugs- to
reduce salivary secretion
SALIVARY FISTULA

85. • Auriculotemporal
syndrome.
• 60% of all
parotidectomy cases.
• Discomfort, localized
facial sweating and
flushing during
mastication.
FREY’S SYNDROME

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

87. • 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

88. • 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

89. • There is no effective treatment, but various options are
described:
i. Injection of Botulinum Toxin
ii. Surgical transection of the nerve fibers
iii. Application of an ointment containing an anticholinergic
drug such as scopolamine

90. • 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

91. References
1. Salivary Gland Disorders: Eugene N. Myers, Robert L. Ferris;
Springer.
2. Maxillofacial Surgery: Second Edition; Volume 1: Peter
Wardbooth.
3. Operative Maxillofacial Surgery; John D Langdon and Mohan F
Patel.
4. Stell and Maran , oncology