Parotidectomy
· Preparation
— Head draped to
encompass the ET
tube, but expose the corner of the mouth and eye
— Shoulder roll. I
prepare the ear
and place a small cotton wick inside which is added to the count
— Neck extension
& turned away.
Suture towel to skin. 30% upward tilt of table
— Bipolar diathermy
— Nerve stimulator
— Patient NOT paralysed
· Incision
Lazy-S: preauricular, around pinna, along SCM to about 1cm below
angle of
mandible
· I apply skin
hooks to the anterior skin flap and raise anterior flap at level
of parotid
fascia just deep to platsyma using diathermy not going beyond
the margins of
the parotid.
· I elevate skin
flaps posteriorly to expose the SCM, mastoid process and
cartilage of external
auditory canal. I suture the skin flaps to the drapes to
maintain exposure
using 2/0 Silk.
· Gt auricular
nerve overlying the SCM about 3cm below the mastoid process is
identified. I
divide the branch that enters the parotid gland.
· I divide and
ligate the retromandibular vein
· Define nerve
— Dissect along
cartilaginous
portion of external auditory meatus
—
Identify
nerve in tympanomastoid fissure by palpating the mastoid process
and where it
turns in to join the external auditory canal is the vertical
surface landmark
of the facial nerve.
—
I
elevate the temporoparotid fascia using an angled haemostat to
elevate the
posterior portion of the parotid gland away from the mastoid
process and uncover
the main trunk of the facial nerve
— Stylomastoid
artery lies anterior
(branch of post auricular a). If it bleeds apply pressure for 5
minutes.
· Dissect along the branches of the
nerve. I retract the
superficial lobe using a small Langenbach or allis clamps and
pass a haemoatat
just superficial to nerve and divide the tissue above the nerve
using scissor
and bipolar diathermy for haemostasis.
At any bifurcation
I follow the more
posterior branch of the nerve
— I continue this
dissection until
each branch has been separated from the parotid tissue.
· I usually transect
the glandular tissue gland after clearance of lesion obtained or
divide duct
anteriorly using 2/0 vicryl if the entire superficial lobe has
been removed.
· I take care to
separate the duct from the buccal branch closely applied to it.
· I ensure
haemostaisis
using pressure with a raytech swab, bipolar diathermy and 4/0
vicryl ties.
· I close the
skin using subcuticular monocryl over a 10F redivac closed
suction drain.
How
do you remove a
benign lesion in the deep lobe of the parotid gland
· First remove
the superficial lobe.
· Free the
facial nerve from the underlying tissue
· The following
vessels must be ligated and divided:
— The
retromandibular vein must be
separated from the marginal manbidular nerve and divided.
— The superficial
temporal artery
and vein
— The external
carotid artery
— Internal
maxillary and transverse
facial arteries
How
do you remove
a malignant lesion that has invaded the facial nerve
· The procedure
is radical parotidecomy.
· The entire
parotid gland and involved parts of the facial nerve are
excised, often
combined with MRND.
· The facial
nerve should be reconstructed using the auricoltemporal nerve or
sural nerve
anatomosed with 10/0 Prolene under an operating microscope.
How
would you
perform facial nerve monitoring
· Peripheral
needle electrodes are inserted at four points: Frontalis
(temporal branch);
orbicularis oculi (zygomatic branch); buccal branch (orbicularis
oris);
depressor of lower lip (marginal mandibular).
· Electromyographic
signal are then recorded producing visual and audible signals
when the facial
nerve supplying them is stimulated.
What
do you do if
you cannot identify the facial nerve
· Use the nerve
stimulator
· If the facial
nerve cannot be identified at the stylomastoid foramen, the
buccal branch can
be identified by its relationship to Stenson’s duct.
· This buccal
branch can then be followed to the temporfacial division of the
nerve.
Complications
of
parotidectomy
· Freys syndrome
(gustatory sweating) 5%
— Damage to
auriculotemporal nerve
interrupting parasympathetic supply
— Sweating of skin
anterior to ear
· Facial nerve
palsy
— Transient 5%
— Permanent 1%
· Fistula 1%
· Formication 1%
· Recurrence 1%
Submandibular
v Impaction occurs
in
— @ orifice:
Intraoral removal
— middle 1/3 duct:
Intraoral removal
— Hilar region
Submandibular galnd
excision
Removal
of stone
· LA injected
over calculus or GA with nasotracheal intubation and pharynx
packed off
Keep mouth open
with dental prop
Grasp the tip of
the tongue with a
towel clip and palpate the stone in the floor of the mouth. If
the stone is not
palpable then do not proceed. If palpable
· Insertion of
proximal and distal 3/0 nylon sutures and use these as stays to
isolate and
control the stone in the duct .
— Retraction
—
Prevention
of proximal migration of calculus
—
Pass
a lacrimal probe into the orifice of the duct and incise onto
the stone
preserving the last 0.5cm of the duct. Lift the stone out. If
you cannot lift
the stone out without compromising the integrity of the duct
orifice sew the
duct lining to the floor of the mouth using 4/0 vicryl rapide.
· Wound left
open
Excision
of submandibular
gland for stone disease
· Preparation
and position as for parotidecomy
— Head draped to
encompass the ET
tube, but expose the corner of the mouth and eye
— Shoulder roll. I
prepare the ear
and place a small cotton wick inside which is added to the count
— Neck extension
& turned away
— Bipolar diathermy
— Patient NOT paralysed
· Incision 3-4cm
below ramus of mandible over gland
· Dissect
directly down onto gland incising the skin, fat, platsyma from
anterior border
of SCM to 3cm from midline
— NO flaps
· Define
inferior border of the gland
—
Identify
and divide facial artery / and retromandibular vein
—
Keeping
very close to the gland capsule reduces the chance of injury to
the marginal
mandibular nerve.
· Dissect off
digastric tendon and anterior belly
· Dissect off
mylohyoid anteriorly
· Dissect
superior border
— Identify and
divide posterior and
anterior facial vein and facial artery
· Dissect deep
portion (posterior) off stylohyoid
v Stylohyoid splits
around posterior
belly digastric
— Identify and
divide facial artery
as comes round stylohyoid
· Apply tissue
forceps to the gland as it passes posterior to the border of
mylohyoid.
· Retract
mylohyoid and separate the deep portion of the gland from muscle
by blunt
dissection
· Dissect the
deep portion of the deep lobe from the hyoglossus muscle gently
using blunt
dissection.
· At this point
identify lingual nerve superior to duct
— Divide fibres
from submandibular
ganglion to gland
· Identify &
preserve hypoglossal nerve inferior (deep) to duct
· I free the
duct as far anteriorly as possible and ligate and divide it
using 2/0 Vicyrl
taking care not to damage the nerves.
· I check haemostasis. I insert a 10F redivac
drain into the wound
bringing the tube out below the midline of the incision.
· I close the platsyma with 4/0 vicryl and 4/0
Monocyryl subcuticular to
skin.