Surgical anatomy of parotid. Parotidectomy with its complications.

1. Parotidectomy
H.SHAMEER AHAMED

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

6. 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

7. TYPES

8. • 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.

9. • 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 such as the overlying skin, the
underlying mandible, the temporal bone and external
auditory canal, or the deep musculature of the
parapharyngeal space.

10. CONSENT
• Scar
• Anaesthesia –greater auricular region
• Facial nerve weakness
• Facial contour
• Frey's syndrome
• Prominence of auricle
• Salivary fistula

11. PREPARATION
Intraoperative facial nerve monitoring.
• for patients with large and/or malignant
tumours,
• undergoing revision surgery,
• retrograde dissection of the facial nerve,
• less experienced surgeons.
The facial nerve monitor should be applied and
testing prior to prepping and draping the patient.

12. ANAESTHESIA
• General anaesthesia
• Short acting muscle relaxant for intubation
only if nerve monitoring planned

13. POSITION AND INFILTRATION
• Supine
• Hyper extend the head and turn to opposite side
• Infiltrate along planned skin incision
• Keep corner of eye and mouth exposed so as to be
able to see facial movement

14. Superficial Parotidectomy
• The most common 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.

15. INCISION
Modified Blair incision
• An incision should be carefully
marked out extending from
• the preauricular region, around the
lobule of the ear towards the
mastoid tip, and then curving back
down to join a neck crease, well
below the angle of the mandible.
• If a preauricular crease is present,
this should be used.

16. ALTERNATIVE INCISION
• Face lift incision : here the pre auricular portion of
the incision passes on or just inside the tragal margin.
The incision is then carried below the lobule of the
ear , turned posteriorly over the mastoid, and
extended within the hairline.
• Unlike Blair's incision which has cervical extension
the facelift incision extends posteriorly and inferiorly
along the hairline.
• Less conspicuous and hence offers better cosmesis.

17. FLAPS
In the face,
• The anterior skin flap should be raised superficial to
the parotid fascia, leaving subcutaneous fat on the
flap.
• very easy to buttonhole this flap.
• If the surgeon sees hair follicles, he is probably
getting too superficial.

18. In the neck,
• the flap may be raised either superficial or
immediately deep to the platysma.
• A 'white line' which defines the plane the
surgeon needs to be in is usually apparent
between these facial and neck planes.
• When raising the flap, it is of utmost importance
that the surgeon keeps palpating the tumour.

19.  Posteriorly, in the neck
The incision should be deepened to the sternomastoid muscle.
The greater auricular nerve can be seen. This is usually
sacrificed.
The anterior border of the sternomastoid should be defined
and followed up to the mastoid tip.
The fascia should be raised anteriorly off the sternomastoid
muscle.
Stay behind any posterior extension of the parotid gland or the
tumour.
Be aware of the proximity of the accessory nerve while
dissecting on the medial surface of the sternomastoid muscle.
The deep cervical fascia should then be incised to display the
posterior belly of the digastric muscle, which is an important
landmark.

20. In the region of the ear,
• The incision should be deepened along the cartilage of
the external auditory canal, taking care not to damage
this cartilage.
• As long as the surgeon stays right on the external
auditory canal, the incision can be safely deepened all
the way to the bony-cartilaginous junction.
• The surgeon should look out for the 'tragal pointer',
which is another useful landmark for the facial nerve.

21. At this point,
• Divide the tissue anterior to the mastoid process
in order to join the dissection in the region of the
external auditory canal to that in the region of
the sternomastoid muscle.
• The depth of this should remain superficial to the
digastric muscle.
• There are many blood vessels around the
mastoid.

22. LOCATING THE FACIAL NERVE
• The facial nerve emerges from the
stylomastoid foramen just superior to the
posterior belly of the digastric muscle, at the
same depth as this muscle.
• The tragal pointer is 1 cm superficial and
above this point.
• The styloid process is medial to the facial
nerve.

23. • Open a broad plane of dissection, do not work down a
narrow 'hole'.
• This may be opened gently in a direction parallel to the
nerve to avoid causing inadvertent damage.
• There are usually many fibrous strands in the region of
the nerve which will need to be divided in order to find
the nerve.

24. • In addition, there are usually some blood vessels
just superficial to the nerve.
• It is best-to divide these blood vessels after
cauterizing them using bipolar diathermy.
• Be certain that the- facial nerve is not cauterized.
• Once the facial nerve is found, it should be
followed to its bifurcation, prior to division of any
parotid tissue.

25. FOLLOWING THE BRANCHES
• The branches should be followed in sequence, starting
either superiorly or inferiorly.
• A clamp should be inserted along the nerve, then lifted
away from the nerve and opened.
• The surgeon should remember that as the branches are
traced distally, they become more superficial,
particularly the upper branches.

26. • The dissection should commence over a
branch which is clear of the tumour, and then
proceed to the successive branches.
• In so doing, parotid tissue should be divided
clear of the tumour.
• The surgeon may come towards the tumour
both superiorly and inferiorly, so the
superficial lobe is well mobilized by the time
the tumour is approached.

27. • For tumours located in either the upper or lower
pole of the gland, it is not necessary to remove
the whole of the superficial lobe.
• It may be possible to remove the tumour with an
adequate cuff while following only either the
upper or lower division branches.
• If the deep part of the tumour capsule is applied
directly onto the branches of the facial nerve, the
surgeon should carefully separate the tumour
from the nerve, taking great care not to rupture
the capsule.

28. CLOSURE
• Prior to closure, a drain should always be placed, as
otherwise the wound will inevitably accumulate
saliva and serous fluid.
• The drain should be ideally left for at least 48 hours.
• Closure is then performed according to surgeon's
preference.

29. DEEP LOBE TUMOURS – TOTAL
PAROTIDECTOMY
• 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.

30. • The operation begins with a standard superficial
parotidectomy.
• The branches of the facial nerve overlying the
tumour are now easily visible and are then separated
from the tumour and mobilized.
• The tumour is then removed between two of the
mobilized facial nerve branches.
• It may be necessary to sacrifice some of the minor
communicating branches, although this should, if
possible, be avoided.
• The underlying tumour is then mobilized and
separated from the deep tissue.

32. REVISION CASES
• It will be necessary to resect the previous scar. should be
prepared to reconstruct the defect.
• If the previous surgery comprised a formal superficial
parotidectomy, then the branches of the facial nerve will be
just beneath the skin flap, without any intervening parotid
fascia, and so will be vulnerable to injury while raising the
skin flap.
• Extending the previous incision, and identifying the correct
plane in virgin tissue, may be a useful manoeuvre.
• Identification of the main trunk of the facial nerve may be
difficult or impossible due to scarring.
• In such cases, it may be necessary to identify the branches
of the facial nerve in the neck and/or face and perform
retrograde dissection.

33. • The retromandibular vein, if still present, is a useful landmark as the
marginal mandibular and cervical branches pass directly over it.
• If this vein has been previously ligated, then the marginal mandibular
nerve may be identified beneath the angle of the mandible, or crossing
the facial artery at the mandibular notch on the inferior border of the
mandible.
• The cervical branch is a variable distance below the marginal
mandibular branch.
• The temporal branch crosses the zygomatic arch 1 cm anterior to the
ear, and courses superficial to the deep temporal fascia, within 1.5 cm
of the lateral border of the eye.
• The zygomatic branch crosses the zygomatic arch further forward.
• The upper buccal branch runs forward roughly 1 cm below the
zygomatic arch
• the lower buccal branch runs towards the corner of the mouth.
• These nerves are superficial to the masseter muscle.
• Retrograde dissection of the branches of the facial nerve may lead to a
higher incidence of neuropraxia than traditional prograde dissection.

34. Complications of parotid surgery
• Early
– Anaesthesia
– Haemorrhage
– Trauma to adjacent structures
• Intermediate
– hematoma
– Facial palsy
• Late
– Salivary fistula
– Gustatory sweating
– cosmesis

35. FACIAL NERVE INJURY
• Facial nerve injury is usually the biggest concern in parotid
surgery.
• Postoperative weakness may be temporary, if the injury is a
neuropraxia.
• more common - between 10 and 50 per cent
• The precise cause of neuropraxia is not known, but probably
results from a combination of trauma while dissecting right
on the nerve, traction injury to the nerve, heat injury
secondary to the use of cautery, and prolonged operating
time.
• The lower division branches, in particular, the marginal
mandibular branch

36. • Permanent, due to transection of,
or cautery injury to, the main trunk
of the facial nerve, or, more
commonly, one of the terminal
branches.
• More commonly in difficult cases,
i.e. large tumours, tumours located
in the deep lobe, malignant cases
and revision surgery.
• The incidence of permanent facial
nerve injury is generally reported
as 0-5 percent

37. HAEMATOMA
• up to 5 percent.
• Small haematomas should be evacuated
promptly, as their presence leads to
compromise of the skin flap with possible
necrosis.

38. SEROMA/SAIIVOMA/SALIVARY FISTULA
• After superficial parotidectomy, leakage of serous
fluid and saliva from the transected parotid tissue is
expected
• This usually lasts for a few days.
• Thus, a drainshould always be placed after parotid
surgery and left in place for at least 2-3 days.
• At this stage, the skin flap should have begun to
adhere to the parotid bed, so obliterating the dead
space in which fluid can accumulate.

39. • If, after removing the drain, patients develop swelling
underneath the wound, this should be aspirated.
• Seromas usually resolve within a few days of serial
aspiration.

40. • Drainage of saliva out of the drain site or through the
wound when the patient is eating is not uncommon.
• A pressure dressing, similar to the type used after
otoplasty, may also be useful to speed resolution.

41. FREY'S SYNDROME/ gustatory
sweating
• Is a phenomenon seen after parotid surgery
where the patient develops sweating on the side
of the face while eating.

42. • Due to transection of
cholinergic secretomotor
fibres to the secretory
units of the parotid gland,
which subsequently sprout
new axons and come to
innervate sweat glands in
the skin flap, which are
also responsive to
acetylcholine.
• Around 10 per cent of
patients who undergo
parotidectomy will
complain of gustatory
sweating.

43. • Objective demonstration is possible using Minor's starch-
iodine test.
• This is performed by covering the affected skin with iodine
solution. Once this has dried, it is dusted with starch powder,
and the patient given a lemon sweet. As a result of absorption
of the wet iodine by starch, the affected area will turn deep
blue purple.

44. • These include raising a thick skin flap, rotation of a superficial
temporal artery-based temporoparietal vascular flap, rotation of
the superficial musculoaponeurotic system (SMAS), and rotation
of sternomastoid muscle flaps.
• Topical anticholinergics may be useful, but have variable efficacy
and may lead to anticholinergic side effects.
• For persistent cases, the most effective treatment would appear
to be injection of botulinum tvpe A toxin. This inhibits
neurotransmitter release and gives long lasting relief, and may be
repeated if recurrent symptoms develop.
• Antiperspirants : Glycopyrrolate 1% lotion
• Tympanic neurectomy

45. OTHER
• Ear numbness is an expected outcome from parotid
surgery. It results from transection of the greater
auricular nerve. Patients are usually very aware of
sensory change immediately after the surgery. Over
the course of several months, the area of numbness
diminishes, but patients are usually left with an area of
persistent numbness around the ear lobe. Patients who
wear earrings will not be able to insert them without
looking in a mirror.
• Duskiness of the postauricular skin flap may occur if
the flap is too large or the blade of the knife was
bevelled while making the skin incision. This usually
settles spontaneously.

46. • Necrosis of the skin tip can occur; this will usually
heal by secondary intention.
• In patients with bulky parotids, a sizeable 'hollow'
may be left on the side of the head after surgery,
particularly after more extensive resections.

47. REFERENCES
• STELL AND MARAN
• SCOTT BROWN 7TH EDITION
• Salivary Gland Disorders: Eugene N. Myers,
Robert L. Ferris; Springer.
• Otolaryngology clinics of north america;
Management of neck in salivary gland cancers:
38(2005) 99-105
• Cumming’s text book of Otolaryngology & head
and neck surgery
• Internet