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Anatomy
and Physiology
The
parotid gland is the largest of the salivary glands and is
divided into deep and superficial lobes by the facial nerve.
The gland lies at the side of the face in front of the ear.
Saliva produced by the gland passes into the mouth via Stenson's
duct, which opens into the oral cavity at the level of the
second upper molar.
Blood
supply to the gland is from the external carotid artery via
the internal maxillary and superficial temporal arteries.
Secretion
within the gland is stimulated by the action of the auricular
temporal nerve and parasympathetic fibres.
The
facial nerve (VII cranial nerve) supplies the motor function
to the face, the main trunk of the nerve enters the posterior
border of the parotid and then divides into its five branches:
-
The
temporal branch - supplies the temporal region of the head
The
zygomatic branch - supplies the lateral orbit
The buccal branch - supplies the nose and mouth
The
marginal mandibular branch - supplies the lower lip and chin
The
cervical branch - supplies the platysma muscle
Sensation
to the ear and ear lobe is from the greater auricular nerve
Numerous
lymph nodes are contained within the parotid gland; they receive
drainage from the external auditory canal, auricle, facial
skin, scalp, eyelids, lacrymal gland and parotid gland.
Adapted
from Siglar & Schuring (1993)
Tumours
of the Parotid Gland
80%
of all salivary gland tumours are in the parotid
80%
of all parotid tumours are benign
80%
of all benign parotid tumours are pleomorphic adenomas
The
remaining 20% of benign parotid tumours comprise; Warthin's
tumour, Oxyphil adenoma and basal cell adenoma (Roland, McRae
& McCombe 1995).
Pleomorphic
Adenomas
The
most common site for this tumour to appear is within the tail
of the parotid gland. It can arise within the deep lobe of
the gland, in which case its' presentation may be that of
a parapharyngeal mass.
Pleomorphic
adenoma presents as a slow growing painless mass in the parotid
gland, which may be tolerated by the individual for many months
or years before seeking medical advice. The facial nerve is
seldom compromised.
The
presence of this tumour is usually confirmed by fine needle
aspiration, although in some instances MRI may be performed
if there is suspicion of deep lobe involvement (Ruckley 1998)
Treatment
Superficial
(suprafacial) parotidectomy is the treatment of choice for
removal of tumours in the superficial portion of the gland.
Total
parotidectomy with preservation of the facial nerve is performed
for those tumours present in the deep or both lobes of the
gland.
In
cases of malignancy where there is direct infiltration of
the nerve by tumour it may be necessary to sacrifice the facial
nerve or branches (leading to a facial palsy), in this case
it may be possible to reconstruct the nerve using a graft.
Complications
of surgery
- Damage
to the facial nerve (facial weakness) may be temporary or
permanent. Temporary weakness may persist for 2-3 weeks
post op but could take several months to fully recover.
- Anaesthesia
(numbness) of the pinna and facial skin close to the site
of the surgical incision - this is due to the division of
the greater auricular nerve resulting in loss of sensation
to the pinna - recovery may take up to 12 months following
surgery.
- Haematoma
- reactionary haemorrhage may occur in the first 2-3 hours
post op
- Frey's
Syndrome (gustatory sweating) - this results in the sweating
over the anterior skin flap when the patient eats. It is
associated with pain in the area of auriculotemporal nerve
distribution and facial flushing. The syndrome is the result
of re-innervation of divided sympathetic nerves to the facial
skin. As a result when the patient eats the salivary reflex
causes dilatation of the blood vessels and secretion from
the sweat glands. The onset is usually within eighteen months
of the surgery but may not develop until years later.
- Salivary
fistula results in leakage of saliva through the wound from
exposed salivary gland tissue. This usually resolves spontaneously
within one month post op.
- Wound
Dimple - parotidectomy (superficial and total) always leaves
a depressio n behind the ascending ramus of the mandible.
This may be quite pronounced immediately post op but may
fill to some degree over the course of the following months
Ruckley
(1998)
Parotidectomy
- Nursing care
| Problem |
Intervention |
Rationale |
| Risk
of post operative haemorrhage/shock |
Observation
of temperature, pulse, BP and respiration |
To
detect early onset of hypo tension which may indicate
reactionary haemorrhage |
| Risk
of dehydration |
Maintain
intravenous fluid infusion until patient able to take
adequate amounts of fluid orally |
To
maintain hydration |
| Risk
of post operative deep vein thrombosis |
Ensure
patient continues to wear TED stockings until fully mobile. |
DVT
prophylaxis |
| Risk
of post operative swelling around wound |
Nurse
patient upright in bed with head well supported by pillows |
To
facilitate drainage from operation site |
| Risk
of reactionary haemorrhage |
Observe
and record amount of drainage in suction bottles - remove
drains when drainage is less than 30 ml in 24hrs - or
according to local protocol (usually after 48 hrs)
Observe skin dimple and wound |
To
detect onset of haemorrhage
Elevation
of skin at site of dimple may denote haemorrhage |
| Risk
of infection |
Observe
wound
Record
temp 4 hourly
|
Increased
erythema around wound site may indicate infection.
Elevated
temperature indicates possible wound infection |
| Altered
sensory perception due to surgical incision - numbness |
Advise
males to shave with caution - use electric razor if possible.
Avoid extremes of heat and cold |
Patient
unable to feel injury to skin or feel temperature extremes |
| Risk
of trauma to facial nerve |
Observe
patient's facial movements i.e. ensure patient is able
to close eye fully; check mouth movements (smile) for
symmetry |
To
detect onset of possible facial nerve paralysis |
Facial
nerve paralysis (in patient who has undergone sacrifice
of the facial nerve)
Inability to close eye on affected side |
Provide eye care: -
Administer artificial tears.
Apply eye shield.
Apply ointment to eye at bedtime and tape lid shut |
To prevent corneal dryness.
To prevent corneal abrasion |
| Inability
to maintain normal mouth function |
Instruct
patient to place food in unaffected side of mouth
Teach
patient to manually remove food from affected side of
mouth
Rinse
mouth with water or mouth wash after eating
|
Inability
to feel presence of food and debris in mouth at affected
side when eating |
| Facial
paralysis |
Encourage
patient to perform range of facial exercises as prescribed
by physiotherapist |
To
maintain muscle tone |
| Post
Operative pain |
Using
pain scale monitor patient's level of pain pre and post
analgesia |
To
assess effectiveness of analgesia |
References
Roland
N. McRae R. & McCombe A. (1995)
Key
Topics in Otolatyngology
Bios Scientific
Publishers
Ruckley
R.W. (1998)
Disease
of the Salivary Glands
Chapter
14 in
Burnard
K. & Young A. (eds) (1998)
The
New Aird's Companion in Surgical Studies
Churchill
Livigstone
Sigler
B. & Schuring T. (1993)
Ear,
Nose and Throat Disorders
Mosby
Further
Reading
Corbridge
R. J. (1998)
Essential
ENT Practice - A Clinical Text
Arnold
Sinah
U. & Mattthew N. (1999)
Surgery
of the Salivary Glands
Otolaryngologic
Clinics of North America Vol. 32. No.5. Oct 1999 pg. 887-906
W.B.
Saunders Co. Philadelphia
Ann
Parker
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