Download neck dissection

NECK DISSECTION
Presented By – Ryan Fernandes
Moderator – Dr B.Ramdas Rai
Prof & Unit Chief III
Anatomy of Neck
SIDE OF NECK
• The side of neck is roughly quadrilateral in
outline
• It is bounded:
Anteriorly by the anterior median line
Posteriorly by anterior border of trapezius
Superiorly by the base of the mandible
Inferiorly by the clavicle
Cervical Fascia
• The cervical fascia is composed of superficial
and deep layers.
• The superficial fascia is not well developed
• The platysma muscle is in the superficial
fascia.
• It arises inferiorly from the
fascia of the pectoralis major
muscle and its fibers
converge as they ascend to
their insertion in the inferior
part of the mandibular
region
• The cutaneous nerves and the
superficial veins course below
this muscle of facial
expression.
• The cervical branch of the
facial nerve innervates this
muscle
DEEP CERVICAL FASCIA(FASCIA COLLI)
• The deep fascia of the neck is condensed to
form:
A. Investing layer
B. Pretracheal layer
C. Carotid Sheath
D. Prevertebral layer
INVESTING LAYER
• Lies deep to the Platysma
• Surrounds the neck like a collar
ATTACHMENTS
SUPERIORLY:
a)External occipetal protruberence
b)Superior Nuchal Line
c)Mastoid Process
d)Base of the Mandible
INFERIORLY
a)Spine of scapula
b)Acromion Process
c)Clavicle
d)Mandible
POSTERIORLY
a) Ligamentum Nuchae
b) Spine of vertebrae C7
ANTERIORLY
a)Symphysis Menti
b)Hyoid Bone
• The investing layer of deep cervical fascia
splits to enclose
MUSCLES – Trapezius & Sternocleidomastoid
SALIVARY GLANDS – Parotid &
Submandibular
SPACES – Suprasternal & Supraclavicular
Pretracheal Fascia
• Encloses & suspends the thyroid gland
Attachments
A)Superiorly – Hydoid bone, oblique line of
thyroid cartilage, cricoid cartilage laterally
B)Inferiorly – Blends with arch of aorta
C)On either side fuses with the front of the
carotid sheath
PREVERTEBRAL FASCIA
• The prevertebral fascia encloses the vertebral
column and the attached erector spinae and
prevertebral muscles and proximal portions of
the cervical and brachial plexuses.
• It creates a complete tube.
• ATTACHMENTS
Superiorly - Base of the skull
Inferiorly – Extends into the superior
mediastinum & attached to the body of 3rd &
4th thoracic vertebra
Anteriorly – Separated from Pharynx by loose
areolar tissue
Laterally – Lost deep to the trapezius
CAROTID FASCIA
• It is the condensation of
fibroareolar tissue around
the main vessels of the
neck
• Consists of the common
carotid artery, internal
jugular vein & vagus nerve
• The Ansa cervicalis lies
embedded in the anterior
wall of the carotid sheath
Triangles of Neck
• The sternocleidomastoid and trapezius muscles
divide the neck into anterior and posterior
triangles
• The triangle is spiral in shape
ANTERIOR TRIANGLE
• The anterior triangle includes the area between the anterior edges of the
sternocleidomastoid muscles.
• The superior limit is the mandible and a line drawn from the angle of the
mandible to the tip of the mastoid process.
• Two double-bellied muscles, omohyoid and digastric, subdivide the
triangles.
• The inferior belly of the omohyoid muscle attaches to the superior
transverse scapular ligament and a portion of the adjacent superior edge of
the scapula. It passes superior to the clavicle and enters the lower portion of
the posterior triangle.
• The intermediate tendon is in the cricoid plane, anterior to the carotid
sheath, and is angulated by a fascial sling attached to the clavicle and the
manubrium.
• The superior belly ascends to the hyoid bone.
It is further subdivided into
• Digastric triangle (1)
• Carotid triangle (2)
• Muscular triangle (3)
• Submental triangle (4)
Muscular Triangle
Boundaries
• Medially the midline
• Inferolaterally Anterior border of the
sternocleidomastoid muscle
• Superolaterally superior belly of omohyoid
• Contents
• 1) Infrahyoid muscles (strap
muscles).
Sternohyoid
Sternothyroid
Thyrohyoid
Omohyoid forming part of the
boundary.
2) The anterior jugular veins,
run in both sides of the midline.
They are joined by the jugular
arch at the suprasternal notch.
Digastric Triangle
Boundaries:
• Anterosuperiorly: Inferior border of the
mandible.
• Inferomedially: Anterior belly of
digastric.
• Inferolaterally: Posterior belly of
digastric.
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Contents:
Submandibular gland
Hypoglossal nerve.
Mylohyoid nerve.
Facial artery and vein.
Submandibular lymph nodes
CAROTID TRIANGLE
Location: Longitudinal
interval between cervical
viscera (pharynx, esophagus,
larynx, trachea and thyroid
gland) medially, and
prevertebral muscles
posteriorly
Formation:
• Prevertebral fascia behind
• Pretracheal fascia medially
Posterior Triangle
• The boundaries of the posterior triangle are the
anterior border of the trapezius muscle and the
posterior edge of the sternocleidomastoid
muscle, and the middle third of the clavicle is
the base.
• The apex of this triangle is the superior nuchal
line.
• This triangle, therefore, presents as a spiral as
the base is anterior and the apex is posterior.
• The triangle is subdivided by the inferior belly of
the omohyoid muscle into smaller entities that
are named for the blood vessels found in them.
There now is a larger, superior, occipital triangle,
and the smaller, inferior, subclavian triangle.
• The muscular floor of the entire posterior triangle
is composed mainly of three muscles whose
fibers run inferolaterally.
• They are, from above down, the splenius capitis,
the levator scapula, and the middle scalene
muscles
• The muscles of the floor are covered by prevertebral fascia,
which creates a fascial carpet. There is also a fascial roof,
generated by the investing layer of the deep cervical fascia.
The contents of the triangle will be described layer by layer,
beginning with the deeper contents found below the fascial
carpet in contact with the muscular floor
• They include
• (a) the occipital artery,
• (b) branches of the deep cervical plexus and
• (c) portions of the brachial plexus.
• The roots of the plexus combine deep to the
sternocleidomastoid
• Structures that pass between the fascial floor and fascial
roof include
the transverse cervical and
suprascapular (transverse scapular) branches of the
thyrocervical trunk,
They pass transversely across the anterior aspect of the
anterior scalene muscle and are separated from the
phrenic nerve by the prevertebral fascia.
The spinal accessory nerve (XI) as it traverses the posterior
triangle. It is found on the anterior surface of, and runs
with, the levator scapula muscle. It will disappear under the
trapezius muscle about 2 inches superior to the clavicle.
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The external jugular vein, which passes obliquely across the sternocleidomastoid muscle, pierces
the deep cervical fascial layers of the subclavian triangle, and ends in the subclavian vein. The
transverse cervical, suprascapular, and anterior jugular veins are tributaries of the external jugular
vein. The inferior belly of the omohyoid muscle creates the lateral boundary of the subclavian
triangle. It is attached inferiorly to the superior surface of the scapula, courses anterosuperiorly,
and passes deep to the sternocleidomastoid muscle, where its intermediate tendon is angulated by
attachments of deep cervical fascia to the clavicle. The superior belly continues to the hyoid bone.
The superficial cervical plexus is created by the ventral rami of C2, C3, and C4. It includes the lesser
occipital nerve (C2), which appears at the posterior edge of the sternocleidomastoid muscle just
inferior to the spinal accessory nerve. It ascends near the posterior edge of the muscle and will
provide sensory innervation to the external ear and the adjacent skin. The superficial cervical
plexus also includes the great auricular nerve (C2, C3), which emerges from the cover of the
sternocleidomastoid muscle just inferior to the lesser occipital nerve, hooks around the posterior
edge of the muscle, and now lies on its superficial surface (Figs. 17, 18). It then passes superiorly
toward the parotid region and provides sensory innervation to the overlying skin and a portion of
the ear. This nerve can frequently be found just posterior to the external jugular vein as it passes
obliquely across the muscle. The transverse cervical nerve (C2, C3) also appears at the posterior
edge of the sternocleidomastoid muscle in the vicinity of the other nerves of this plexus. It wraps
itself around the posterior edge of the muscle and passes P.273
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transversely across its external surface to reach the anterior triangle. It will then divide into
ascending and descending branches that will provide cutaneous sensory innervation to the anterior
triangle.
• The supraclavicular nerves (C3, C4) first appear in the same area, just
below the site of emergence of the other nerves, and then divide into
medial, intermediate, and lateral branches. They provide cutaneous
sensory innervation to the anterior aspect of the thorax down to the level
of the second rib. All branches of the superficial cervical plexus, and the
spinal accessory nerve, are quite close to each other as they first appear in
the posterior triangle at the edge of the sternocleidomastoid muscle. If
one divides the posterior edge of this muscle into thirds, at the junction of
the middle and superior third is the site where all these nerves can be
found gathered in a small localized area. This is referred to as the nerve
point. They will then diverge as they head toward their specific
destinations. As the nerves pass through the posterior triangle, it will be
seen that the spinal accessory nerve is the most superior of all the nerves
that are in the triangle. Therefore, incisions that are made superior to the
spinal accessory nerve are not likely to encounter any important nerves.
This area has been referred to as the carefree area; whereas, an incision
made below this nerve can injure major structures and is called the careful
area.
INTRODUCTION
• The single most important factor affecting the
prognosis of squamous cell carcinoma of the
head & neck is the status of cervical lymph nodes
• Metastasis to regional lymph nodes reduces the 5
year survival rate by 50% compared with that of
patients with early stage disease
• Therefore management of cervical lymph nodes
is an important component in the overall
treatment plan for patients with squamous cell
carcinoma of head & neck
Anatomy of the Cervical Lymphatics
• Cervical lymph nodes are classified according to the
system developed at Memorial Sloan-Kettering Cancer
Center in the 1930s.
• This system divides the lymph nodes in the lateral
aspect of the neck into five nodal levels, I through V,
• In addition, lymph nodes in the central compartment
are categorized into level VI and those in the superior
mediastinum as level VII
• Recently, level I, II, and V nodes were subclassified into
levels IA and IB, IIA and IIB, and VA and VB..
• Level IA includes the submental lymph nodes,
whereas level IB includes the submandibular
lymph nodes.
• Level IIA includes lymph nodes below the
accessory nerve, whereas IIB includes nodes
above the accessory nerve.
• The posterior triangle has been subdivided into
levels VA and VB, with the dividing line being the
accessory nerve in the posterior triangle.
• This subdivision is based on patterns of lymph
node spread from various primaries. s
NODAL FACTORS AFFECTING
PROGNOSIS
• Characteristics of regional nodes that affect prognosis include
1. the presence of pathologically positive nodes,
2. size of the metastatic lymph node,
3. the number of lymph nodes involved, and
4. the location of the lymph nodes.
Involvement of the lower cervical nodes (level IV) and the lower
posterior triangle lymph nodes has a very poor prognosis.
Another important prognostic factor is the presence of extranodal
spread where the capsule of the lymph node is ruptured, resulting
in invasion of the surrounding soft tissues.
RISK FACTORS FOR NODAL METASTASIS
• The risk for cervical node metastases is influenced by characteristics
of the primary tumor such as location, size, and histology.
• The risk for lymph node metastases increases for more posteriorly
located tumors, i.e., lips, oral cavity, oropharynx, and hypopharynx.
• For example, oropharyngeal cancers are at higher risk than oral
cavity tumors.
• Lesions of the tonsil and base of tongue have a very high incidence
of nodal metastases.
• Tumors of the hypopharynx universally have lymph node
metastases.
• The greater the T size of the primary tumor, the greater the
probability of having lymph node metastases
PATTERNS OF NODAL METASTASIS
ASSESSMENT OF CERVICAL
LYMPHADENOPATHY
• CLINICAL EXAMINATION- 77% accuracy
• FNAC
• ULTRASOUND SCAN - 77 -90%
no absolute criteria for benign / malignancy
( absence of hilar echoes and increase in short
axial length)
• CT scan-:
High diagnostic accuracy
Criteria – lymph node short axis, diameter larger than 1 cm
cluster of 3 / more borderline enlarged node
nodal necrosis/ patchy enhancement with in node
• MRI -:
Similar accuracy
Better in N0 neck and
presence of deep invasion
• CT PET scan-:
To detect occult metastasis, residual /recurrent following surgery/
radiation.
• Open biopsy
SENTINAL NODE
SENTINAL NODE BIOPSY
CLASSIFICATION OF NECK DISSECTION
• The Classical operation of Radical Neck
Dissection was 1st performed by George
Washington Crile
• The operation was popularised by Hayes
Martin
• Oswald Suarez from Argentina was the 1st to
describe functional neck dissection in 1963,
now called Modified Radical Neck Dissection
COMPREHENSIVE NECK DISSECTION
• Comprehensive neck dissections involve the removal of all lymphatic
tissue in the lateral neck (levels I to V) and are generally carried out for the
clinically positive neck (N+).
• They can be classified into radical and modified radical neck dissection
• Radical neck dissection involves the removal of lymph nodes in levels I to
V, but also the sternocleidomastoid muscle, internal jugular vein, spinal
accessory nerve, and submandibular salivary gland.
• Modified radical neck dissection (MRND) is divided into type I, II, or III,
depending on the structures that are preserved. Type I MRND involves
preservation of one structure, the spinal accessory nerve. Type II involves
preservation of two structures, the spinal accessory nerve and the
sternocleidomastoid muscle. Type III involves preservation of the spinal
accessory nerve, internal jugular vein, and the sternocleidomastoid
muscle.
SELECTIVE NECK DISSECTION
• Selective neck dissection spares all nonlymphatic tissue, including
the sternocleidomastoid muscle, internal jugular vein, and spinal
accessory nerve.
• However, it does not remove all the lymphatic tissue on the
involved side of the neck as does a comprehensive neck dissection,
but rather uses the selective removal of nodal regions at risk.
• This is determined by the predictive pattern of metastases based on
the location of the primary tumor.
• It is based on the clinical observation that squamous cell carcinoma
of the upper aerodigestive tract metastasizes in a predictable and
sequential pattern.
• Selective neck dissections are therefore generally carried out for
the neck with clinically negative disease (N0), where there is at least
a 15% to 20% risk of occult metastatic disease.
• Common selective neck dissections include  The supraomohyoid neck dissection, in which lymph nodes in levels
I to III and the submandibular salivary gland are removed
 The extended supraomohyoid neck dissection, in which lymph
nodes in levels I to IV and the submandibular gland are removed T
 he anterolateral neck dissection (LND), in which lymph nodes in
levels II to IV are removed
 Posterolateral neck dissection (PLND), in which lymph nodes in
levels II to V and also the suboccipital and retroauricular lymph
nodes are removed and
 Central or anterior compartment neck dissection, in which lymph
nodes in the prelaryngeal, pretracheal, and paratracheal regions are
removed
SUPRAOMOHYOID NECK DISSECTION
• Supraomohyoid neck dissection (SOHND) is
recommended for squamous cell carcinoma of the oral
cavity with a high risk of micrometastases in a neck
that is clinically negative for disease.
• Extended supraomohyoid neck dissection is
recommended for squamous cell carcinoma of the
lateral tongue. This is based on the observation that
patients with primary carcinoma of the lateral border
of the oral tongue have a small but increased risk of
skip metastases to level IV compared with other sites in
the oral cavity. Therefore, selective treatment of the N0
neck in lateral tongue cancer should include level IV.
• Anterolateral neck dissection (LND) is recommended for squamous cell
carcinoma of the larynx or pharynx with a high risk of micrometastases in
a neck that is clinically negative for disease. If the primary tumor crosses
the midline, this procedure is carried out bilaterally.
• LND is indicated for cancer of the oropharynx when the primary tumor is
treated with surgery in a neck that is clinically negative for disease.
• If postoperative radiation therapy is indicated, it is not necessary to
perform bilateral LND because radiation alone is effective in treating the
node-negative contralateral neck.
• Posterolateral neck dissection (PLND) is recommended for primary
cutaneous malignancies of the posterior scalp (e.g., melanoma and
squamous cell carcinoma).
• Central compartment neck dissection is recommended for differentiated
thyroid carcinoma in which the disease is limited to the pretracheal and
paratracheal nodes.
Classification of Different Types Of
Neck Dissection
PREOPERATIVE PREPARATION
• Patient consent
• Medical fitness
• Tracheostomy
• Planned treatment
• Antibiotic coverage
POSTION OF THE PATIENT
•
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•
Head is turned to the opposite side
Hyperextended resting on a head ring
A sandbag is placed under the shoulder
Upper end of the table is elevated to
approximately 30 degrees
• When draping, the following surgical landmarks
must be visible
Mastoid tip
Ear lobe
Body of the Mandible
Midline of the Chin
Suprasternal notch
Clavicle
Region of Trapezius muscle insertion
TYPE OF INCISION
• MAIN GOALS –
1. Assure adequate vascularisation of the flaps
2. Adequate exposure of the surgical field
3. Consider the localisation of the primary tumor
4. Adequate protection of the major vessels if the
sternocleidomastoid muscle is resected
5. Preoperative factors such as previous radiotherapy
6. Include previous surgical fields(scars, incisions for
biopsies)
7. Produce accepatable cosmetic results
• APPROACHES-:
1.Tri-radiate incision and its modification
2.Hayes Martin double ‘Y’ incision
3.McFee incision
4.Apron flap incision
5.J incision
6.Hockey stick incisions and its modifications
Tri-radiate incision
Advantage
Provides good exposure to
surgical site
Disadvantage
Flap necrosis is high due to
disruption of vasculature of
skin flaps
Occurrence of flap separation
at the trifurcation site.
Modification of Tri-radiate
• Schobinger (1957)
• Cramer & Culf (1969)
• Conley (1970)
Schobinger (1957)
Conley (1970)
• Suggested a
posteriorly curving
vertical incision
Cramer and culf
• ‘S’ shaped vertical
incision
• avoid over the
carotid
Hayes Martin Incision
• a paired ‘Y’ incision
• This flap most often
gets cyanosed.
• Flap necrosis and
carotid exposure is
more in this type of
incision.
McFee Incision
• It avoids a vertical limb.
• Two horizontal incisions
are used one in
submandibular region
and other in the
suprasclavicular region.
• IRRADIATED NECK
Apron flaps
• Described by Latyschevsky and
Freund 1960.
• Advantages
- Carotid artery is well protected
- Protects the descending arterial
recovery
• Disadvantages
-It will damage the ascending arterial
and venous recovery
-Venous congestion and oedema
Hockey stick incision
• Lahey et al (1940)
described.
• Modified for RND by
Eckert & Byars 1952.
• It has a longitudinal and
transverse incision
• B/L hockey stick incision
allows the deglovement
of the whole neck.
• Tracheostomy along with
bilateral neck dissection
Generic Steps for All Neck Dissections
• Desired incision is marked using ink
• Incision is made with No. 10 blade through
skin down to platysma
• Skin flaps are elevated keeping the platysma
as identification
Four areas of special attention during
neck dissection
• Lower end of internal jugular vein
• Junction of lateral border of clavicle with
lower edge of trapezius
• Upper end of internal jugular vein
• Submandibular triangle
MODIFIED RADICAL NECK DISSECTION
• Incision
For MRND type I, a single trifurcate neck incision
is the most frequently employed incision
Procedure
• The dissection begins with elevation of the posterior
skin flap.
• Skin is incised & the incision is deepened through the
subcutaneous tissue and then through the platysma
muscle.
• The posterior flap is then raised in the subplatysmal
plane by applying traction and countertraction
• The flap is elevated up to the anterior border of the
trapezius muscle.
• During this elevation, care is taken not to enter the
posterior triangle fat pad to prevent any injury to the
spinal accessory nerve
• The anterior border of trapezius muscle is skeletonized and
then care is taken to identify the spinal accessory nerve
• This can be done either by identifying it as it passes onto
the undersurface of the trapezius muscle in the lower part
of the neck, or by identifying it 1 cm superior to Erb's point
(which is a plexus of cervical cutaneous nerves on the
posterior border of the sternocleidomastoid muscle
approximately 6 cm from the inferior lobule of the ear).
• Once identified, the nerve is dissected out from its entry in
the trapezius muscle up to the posterior border of
sternocleidomastoid muscle.
• The nerve is then followed up through the
sternocleidomastoid muscle, dividing the muscle
• The nerve is then carefully dissected out in a cephalad direction along the
lateral border of the internal jugular vein up to its exit from the jugular
foramen at the skull base under the posterior belly of the digastric muscle.
• Once this is done, the nerve is then carefully separated from underlying
tissue
• The superior attachment of the sternocleidomastoid muscle is then
detached from the mastoid process, and fibrofatty tissue lying in the
supra-accessory triangle is dissected off the muscular floor, working from
a lateral-to-medial direction.
• The tissue is sequentially dissected off the splenius capitis muscle,
followed by the levator scapulae muscle.
• Working in a lateral-to-medial direction, the anterior border of each
subsequent muscle is exposed.
• The posterior scalene muscle is exposed and then the inferior belly of
omohyoid muscle is divided at its attachment on the scapula.
• The specimen to be retracted medially, allowing further dissection of the
muscular floor, first exposing the middle scalene muscle and then the
anterior scalene muscle with the brachial plexus in between.
• On the anterior surface of the anterior scalene
muscle, the phrenic nerve is identified passing
in a lateral-to-medial direction
• Once the phrenic nerve is identified and
preserved, the dissection then continues in a
cephalad
• The specimen is further retracted medially to
expose the internal jugular vein, common
carotid artery, and the vagus nerve.
• Attention is then turned to the anterior skin flap.
• The transverse skin incision is completed from the
trifurcation point up to its medial end.
• The skin, subcutaneous tissue, and platysma muscle are
divided, and an anterior subplatysmal flap is elevated up to
the midline superiorly and to the medial end of the
sternocleidomastoid muscle at its attachment to the
sternum inferiorly.
• The sternal and clavicular heads of sternocleidomastoid
muscle are divided.
• The muscle is then retracted in a cephalad direction and
loose areolar tissue is dissected to expose the carotid
sheath.
• The lateral border of the strap muscles are retracted medially,
allowing the carotid sheath to be fully exposed.
• The sheath is opened and the common carotid artery, vagus nerve,
and internal jugular vein identified and dissected.
• The internal jugular vein is then divided between clamps and
doubly ligated with 2-0 silk ties .
• A 3-0 chromic catgut transfixion suture is used to secure the distal
end of the vein.
• Lymphatic tissue lying lateral to the internal jugular vein
encompassing the thoracic duct on the left side and unnamed
lymphatics on the right hand side of the neck are carefully divided
in clamps and ligated with silk ties to prevent chyle leakage.
• The middle thyroid vein needs to be identified, divided, and ligated
with 3-0 silk as it enters the medial aspect of the internal jugular
vein.
• Working in a cephalad direction, the hypoglossal nerve is then
identified beyond the bifurcation of the carotid artery.
• The anteromedial limit of the dissection is the anterior belly of the
omohyoid muscle.
• This is incorporated into the specimen by dissecting it up to its
attachment to the hyoid bone, where it is then detached.
• Careful dissection at this level allows identification of the superior
thyroid vessels.
• The superior thyroid vein is divided and ligated and the superior
thyroid artery is preserved.
• The soft tissue from the submental triangle is then
dissected off the ipsilateral anterior belly of the digastric
muscle, followed by the mylohyoid muscle.
• The submandibular duct is dissected, divided, and ligated.
• Care is taken not to enter the fascia of the hyoglossus
muscle as it is in this plane that the hypoglossal nerve is
located.
• The submandibular gland is now retracted laterally and
separated from the posterior belly of the digastric muscle.
• The proximal portion of the facial artery is then identified
on the posteromedial aspect of the posterior belly of the
digastric muscle. It is divided in clamps and ligated with 3-0
silk
• The tail of parotid is retracted cephalad, allowing access to the
posterior belly of the digastric muscle.
• After this, the posterior belly of the digastric muscle is retracted
cephalad with a deep right-angled retractor.
• The occipital artery and vein lying superficial to the internal jugular
vein are divided and ligated, allowing exposure of the upper end of
the internal jugular vein at the base of the skull.
• The vein is then skeletonized circumferentially and then doubly
ligated with 2-0 silk .
• The specimen is then able to be delivered.
• Meticulous hemostasis is then secured with ligation or
electrocautery and the wound irrigated with a plentiful amount of
saline.
• Large suction drains are inserted through stab incisions in the lower
skin flaps .
• One drain is placed along the anterior border of the trapezius
muscle and held in position with a loop of chromic catgut suture.
• An anterior drain is placed along the strap muscles, medial to the
carotid artery, and again secured in place with a loop of chromic
catgut suture.
• Both drains are secured to skin with a purse-string silk suture. The
incision is then closed in two layers using 3-0 chromic catgut
interrupted sutures for the platysma muscle and 5-0 nylon for skin.
• Suction on the drains is maintained while the wound is being
closed. An airtight closure is required to ensure adherence between
the skin and deep structures of the neck. The drains remain in place
for 4 to 7 days and are removed only once minimal serous drainage
is present.
Selective Neck Dissection
Supraomohyoid Neck Dissection (SOHND)
• The skin incision used for the SOHND is in a skin crease
approximately two fingerbreadths below the inferior
border of the mandible
• The superior flap is raised first in the subplatysmal plane.
• Fascia overlying the submandibular gland containing the
marginal branch of the facial nerve is incised and this layer
is raised along with the superior skin flap
• Dissection of the submental and submandibular triangles is
then carried out in an identical fashion to that described for
MRND type I.
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Dissection then proceeds to level II and III lymph nodes.
An inferior skin flap is raised in the subplatysmal plane down to the posterior edge of the
sternocleidomastoid muscle laterally and the sternal attachments of sternocleidomastoid muscle
inferiorly.
Fascia on the anterior border of the sternocleidomastoid muscle is incised, and the fascial
attachments between the tail of parotid gland and sternocleidomastoid muscle are dissected,
allowing exposure of the posterior belly of the digastric muscle.
Next, the spinal accessory nerve is identified as it pierces the upper third of the
sternocleidomastoid muscle.
The nerve is dissected out, up toward the proximal end of internal jugular vein and posterior belly
of the digastric muscle.
The fat pad and lymph nodes lying in level IIb are then carefully dissected out
This tissue is then passed under the spinal accessory nerve and retracted in a medial direction using
a clamp.
With the sternocleidomastoid muscle retracted laterally the tissue overlying the cervical plexus of
nerves is divided.
Clamps are placed on the soft tissue and retracted medially, allowing the underlying nerves from
the cervical plexus to be visualized
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Dissection then proceeds in a lateral-to-medial direction in a plane just superficial to these nerves.
The lower limit of the dissection is the inferior belly of the omohyoid muscle
The phrenic nerve is then identified on the anterior scalene muscle and carefully preserved.
The carotid sheath fascia is divided,
Working from a lateral-to-medial direction, the soft tissue encompassing levels II and III lymph
nodes are dissected off the internal jugular vein.
The anteromedial limit of the dissection is the superior belly of the omohyoid muscle.
The soft tissue containing lymph nodes from the midjugular chain is then retracted in a cephalad
direction and dissected off the internal jugular vein and superior belly of omohyoid muscle.
The superior thyroid artery is preserved but the vein needs to be divided and ligated
Superiorly, the common facial vein is then identified on the medial aspect of the internal jugular
vein and divided in clamps and ligated with 3-0 silk.
The hypoglossal nerve is identified and tissue lying lateral and inferior to it dissected.
The specimen encompassing levels I, II, and III is then delivered.
The incision is closed in two layers with interrupted 3-0 chromic catgut for the platysma muscle and
5-0 nylon for skin.
Anterolateral Neck Dissection
• This dissection is usually carried out as a staging procedure in
conjunction with excision of primary carcinoma of the larynx or
pharynx in a patient with a neck with clinically negative disease.
• This involves dissection of lymph nodes from levels II to IV.
• The incision is therefore planned according to resection of the
primary tumor.
• This is usually a transverse incision at the level of the thyrohyoid
membrane from the posterior border of one sternocleidomastoid
muscle to the midline
• Upper and lower skin flaps are raised in the subplatysmal plane.
• Fascia on the anterior border of the sternocleidomastoid muscle is
incised and elevated medially to expose the underlying jugular
lymph nodes
• The omohyoid muscle is divided inferiorly to allow dissection of
level IV nodes.
• As in the SOHND, the accessory nerve is identified as it pierces the
medial aspect of the sternocleidomastoid muscle and is traced
superiorly.
• Lymph nodes in level IIb superior and lateral to the nerve are
dissected as described for the SOHND.
• Dissection again proceeds lateral to medial, identifying the anterior
scalene muscle, phrenic nerve, and roots of the cervical plexus.
• The carotid sheath is opened to identify the vagus nerve, carotid
artery and internal jugular vein.
• Middle thyroid, superior thyroid, and common facial veins on the
medial aspect of the internal jugular vein are divided and ligated
with 3-0 silk to allow the specimen to be reflected medially.
• The specimen may be left attached to the primary tumor or may be
removed separately. Insertion of drains and wound closure are as
described previously.
Posterolateral Neck Dissection
• This is carried out for clinically negative neck disease for
either melanoma or squamous cell carcinoma of the
posterior scalp.
• It involves the removal of lymph nodes in levels II to V,
including the suboccipital and retroauricular lymph nodes.
• A hockey-stick incision is used (Fig. 9D), extending from the
mastoid tip along the anterior border of the trapezius
muscle and then curving anteriorly just superior to the
clavicle.
• An anterior skin flap is elevated in the subplatysmal plane
up to the anterior border of the sternocleidomastoid
muscle.
•
•
•
•
•
•
•
The spinal accessory P.333 nerve is identified in the posterior triangle as described
previously and dissected out from the inferior aspect of the trapezius muscle up to
the posterior border of the sternocleidomastoid muscle.
Dissection of the posterior triangle lymph nodes proceeds as described previously.
To dissect out the upper, middle, and lower jugular lymph nodes, the
sternocleidomastoid muscle is retracted medially.
The fascia of the carotid sheath is divided, identifying the carotid artery, vagus
nerve, and internal jugular vein.
Dissection of level II to IV lymph nodes proceeds in a caudal-to-cephalad fashion,
and the specimen including the posterior triangle soft tissue is delivered.
In order to include the postauricular and suboccipital lymph nodes, a lateral
extension of the P.334 upper end of the skin incision from the mastoid process to
the occipital tubercle is carried out.
The trapezius muscle is then detached from its nuchal attachment, allowing
exposure of lymph nodes in the suboccipital triangle, which are then removed as a
separate specimen.
COMPLICATIONS
• Cervical Complications-:
-: Local Complications
Infection
Serohematoma
Wound dehiscence
Chylous fistula
-: Vascular Complications
Hemorrhage
Vascular blowout
-: Neural Complications
Spinal accessory nerve
Phrenic nerve
Hypoglossal nerve
Vagus nerve
Sympathetic trunk
Mandibular branch of CN VII
Brachial plexus
• General Complications
-: Pulmonary Complications
Pneumonia
Pulmonary embolism
-: Stress ulcer
-: Sepsis
Other