surgical anatomy of neck

1. SURGICAL ANATOMY OF NECK,
CLASSIFICATION OF NECK
DISSECTION

2. FASCIAL LAYERS OF THE NECK
 Superficial cervical fascia
 Deep cervical fascia
 Superficial layer
 SCM,
 Strap muscles,
 Trapezius
 Middle or Visceral Layer
 Thyroid
 Trachea
 Esophagus
 Deep layer (also prevertebral fascia)
 Vertebral muscles
 Phrenic nerve

3. FASCIA OF NECK
Superficial fascia:
- Connective tissue below
dermis
- Completely surrounds neck -
thin and hard to demonstrate
- Contains Platysma

4. DEEP CERVICAL FASCIA
 Form the boundaries of compartments
 Used as a guide to surgical dissection
 Allow the neck structures to glide past one another
 Supports the thyroid, lymph nodes and blood vessels
 Fascial spaces can communicate infection or fluid to
other regions of the body

5. Deep Cervical Fascia

6. Deep Cervical Fascia

7. SUPERFICIAL STRUCTURES
 Platysma
 External jugular vein
 Marginal mandibular nerve

8. Platysma
•Muscle of Facial Expression
•Innervated by the cervical
branch of the facial nerve
•Blood supply to skin through
this muscle
•Strength to flap

9. EXTERNAL JUGULAR
VEIN
• The vein is formed by the union of the
posterior division of the retromandibular
vein with the posterior auricular vein and
begins near the mandibular angle just
below or in the parotid gland.
• It descends from the angle,
running obliquely, superficial
to the sternocleidomastoid, to
the root of the neck.
• Here it crosses the deep fascia and ends in
the subclavian vein, behind the clavicle.

10. MARGINAL MANDIBULAR NERVE
Present-
 Superficial layer of deep cervical
fascia and advantasia of facial vein
 More than one branch often present
 Should be preserved in neck
dissections
 Can be preserved by-
Identifying then dissecting along its
course and reflecting superiorly it flap

11. MUSCLES

12. STERNOCLEIDOMASTOID MUSCLE
(SCM)
• Origin –
1) medial third of the clavicle
(clavicular head)
2) manubrium (sternal head)
• Insertion – mastoid process
• Nerve supply – spinal accessory
nerve (CN XI)
• Blood supply –
1. occipital a. or direct from ECA
2. superior thyroid a.
3. transverse cervical a.

13. OMOHYOID MUSCLE
• Origin – upper border of the scapula
• Insertion –
Intermediate tendon
1. hyoid bone lateral to the sternohyoid muscle
• Blood supply – Inferior thyroid a.
Innervation – Upper belly-Superior root of ansa
Inferior belly- Ansa Cervicalis
• Function –
1. depress the hyoid
2. tense the deep cervical fascia

14. OMOHYOID MUSCLE
Surgical considerations
– Landmark demarcating level III from IV
– Inferior belly lies superficial to
• The brachial plexus
• Phrenic nerve
• Transverse cervical vessels
– Superior belly lies superficial to IJV

15. DIGASTRIC MUSCLE
• Origin – digastric fossa of the mandible (at
the symphyseal border
• Insertion –
1) hyoid bone via the intermediate tendon
2) mastoid process
• Function –
1) elevate the hyoid bone
2) depress the mandible (assists
lateral pterygoid)

16. DIGASTRIC MUSCLE
posterior belly
•Origin – Deep to SCM
superficial to:
• ECA
• ICA
• IJV
• Assessory nerve
• Hypoglossal nerve

17. DIGASTRIC MUSCLE
 Intermediate tendon-
Associated superficially with-
• Submandibular gland
• Facial artery
o Anterior belly
• Landmark for identification of mylohyoid for
dissection of the submandibular triangle

18. TRAPEZIUS MUSCLE
• Origin – 1) medial 1/3 of the sup. Nuchal line
2) external occipital protuberance
3) ligamentum nuchae
4) spinous process of C7 to T12
• Insertion – 1) lateral 1/3 of the clavicle
2) acromion process
3) spine of the scapula
• Function – elevate and rotate the scapula and
stabilize the shoulder

19. TRAPEZIUS
• Surgical considerations
– Posterior limit of Level V neck dissection
– Denervation results in shoulder drop and
winged scapula

20. TRIANGLE OF NECK

21. Anterior Triangle

22. 1. Submandibular triangle
2. Carotid triangle
3. Muscular triangle
4. Submental triangle

23. Submental Triangle
formed by
• the anterior bellies of
the digastric,
• hyoid,
Content-
• Submental lymph nodes;3 or 4 in
no. situated in the superficial fascia
below the chin
• Submental branch of facial artery
• Commencement of ant. Jugular
vein
Floor- mylohyoid

24. SUBMANDIBULAR TRIANGLE
formed by
mandible, posterior belly of the
digastric, and anterior belly of the
digastric
Floor
anteriorly – mylohyoid
Posteriorly- hyogloassus

25. CAROTID TRIANGLE
formed by
superior belly of the omohyoid, SCM,
posterior belly of the Digastric

26. Muscular Triangle
formed by
the midline, superior belly of
the omohyoid, and SCM
CONTENT
• No significant structures
• Beneath its floor lie thyroid
glands,larynx,trachea,esophagus
• Infrahyoid muscle are present in this
triangle

27. Posterior Triangle of the Neck
1. Occipital Triangle
2. Subclavian Triangle

28. OCCIPITAL TRIANGLE
BOUNDARIES
• Front-post. Border of SCM
• Behind-anterior border of trapezius muscle
• Below- inf. Belly of omohyoid
• Floor-
1. spinalis capitis muscle
2. levator scapulae
3. scalenus medius and posterior

29. SUPRACLAVICULAR TRIANGLE
Formed by –
Inferior belly of omohyoid
SCM
Clavilce

30. CONTENTS OF TRIANGLES

31. CONTENTS OF SUBMANDIBULAR TRIANGLE
• Submandibular gland and its lymph
nodes
• Subamdibular duct
• Facial vein
• Facial artery
• Hypoglossal nerve and
accompanying vein
• Lingual artery

32. CONTENTS OF CAROTID TRIANGLE
 CCA and its two terminal branches
 In the carotid triangle the ICA is posterolateral while
ECA is anteromedial
 Branches of ECA
1. Superior thyroid artery
2. Lingual artery
3. Facial artery
4. occipital artery
5. Ascending pharyngeal artery
 INT CAROTID artery does not give any branches in
this triangle
Arteries

33. NERVES IN CAROTID TRIANGLE
 Portion of spinal part of
accessory nerve
 Loop of hypoglossal
 Ansa Cervicalis
 Vagus nerve; passes downward
within carotid sheath between
IJV laterally and carotid system
of arteries medially

34. SPINAL ACCESSORY NERVE
• Originates from jugular foramen
• Crosses the IJV
• Downward backward to upper part of SCM
• Descends obliquely in level II (forms Level IIa
and Iib
• Penetrates the deep surface of the SCM
• Exits posterior surface of SCM deep to Erb’s
point
•

35. SPINAL ACCESSORY NERVE
• In posterior triangle and lies between
superficial cervical fascia and prevetebral
fascia ;above the levator scapulae
• Before it enters SCM joined by C2
• Before it enters Trapizus joined by C3 and C4
• Enters the trapezius approx. 5 cm above the
clavicle

36. CLINICAL SIGNIFICANCES
 While operating in the posterior triangle one should
keep in mind that this nerve runs in the roof and not
floor and hence can be damaged during elevation
of flap itself.
 Damage to spinal accessary leads to-
Paralysis of SCM and Trapizius
• leading to asymmetric neckline
• a drooping shoulder
• Winged Scapula
• weakness of forward elevation of the shoulder

37. ERB’S POINT
• At posterior border of the SCM where the four
superficial branches of the cervical plexus emerge
from behind the SCM.
 greater auricular
 lesser occipital
 transverse cervical
 supraclvicular nerve
• approximately at the junction of the upper and
middle thirds of this muscle.
• the accessary nerve courses through the to enter
the anterior border of the trapizius muscle
• The spinal accessory nerve can often be found 1 cm
above Erb's point

38. HYPOGLOSSAL NERVE

39. ANSA CERVICALIS
• Part of the cervical plexus
•
• It lies superficial to the IJV in carotid
triangle.
• Superior root
• Inferior root
• Branches from the ansa cervicalis
innervate
• sternothyroid
• sternohyoid
• omohyoid muscles .

40. VEINS PRESENT IN THE CAROTID TRIANGLE
 Internal jugular vein; extends
from the base of skull to the
root of neck and collects
blood from the brain
,superficial part of the face
and neck
 Also present are the
tributaries of IJV such as
sup. Thyroid, lingual
,common facial,
pharyngeal,and sometimes
occipital veins

41. LIGATION OF INTERNAL JUGULAR VEIN
 Lower end of internal jugular vein is approached first by
dividing the SCM because it reduces chances of air emboli
and vessel doesn't get collapsed.
 Care should be taken not to harm a thoracic duct
 Upper end can be identify by dividing SCM
 The position can be located by palpation of transverse portion
of atlas over which it lies .

42. CONTENTS OF OCCIPITAL TRIANGLE
 Cutaneous branches of cervical
plexus
1. lesser occipital nerve(c2)
2. great auricular nerve(c2,c3)
3. transverse cervical nerve(c2,c3)
4. Supraclavicular nerve(c3,c4)
• Lies on levator scapulae and
Saclenus medius muscle
• Lies deep to Prevertibral fascia,
IJV , SCM

43. BRANCHES

44. PHRENIC NERVE
 Formed by nerve roots C3-5
 Runs obliquely toward midline on the anterior surface of
anterior scalene
 Covered by prevertebral fascia
 Lies directly on anterior surface of anterior scalene muscle
 Lies posterior and lateral to the carotid sheath
 Sole nerve supply to the diaphragm

45. CONTENTS OF POSTERIOR TRIANGLE
OCCIPITAL
ARTERY
GREAT
AURICULAR N.
LESSER
OCCIPITAL N.
ACCESSORY N.
SUPRA
CLAVICULAR
NERVES
TRANSVERSE
CERVICAL
NERVE
EXTERNAL
JUGULAR
VEIN

46. CONTENTS OF SUPRACLAVICULAR TRIANGLE
[1]nerves-
(a)trunks of brachial plexus
[2]vessels-
(a)Third part of subclavian
artery and subclavian vein
(b)Suprascapular artery and
vein
(c) transverse cervical artery
(d)Lower part of external
jugular vein
[3]lymph nodes-
[4] Thorasic duct

47. POSTERIOR TRIANGLE - deeper
BRACHIAL
PLEXUS ROOTS
&TRUNKS
TRANSVERSE
CERVICAL
ARTERY
SUPRASCAPULAR
ARTERY
SUBCLAVIAN
ARTERY
PHRENIC NERVE
NOSE
SUBCLAVIAN
VEIN
NOTE: SUBCLAVIAN VEIN IS NOT IN POSTERIOR TRIANGLE

48. THORACIC DUCT
• Conveys lymph from the entire
body back to the blood
• Enters the base of neck lies
between right subclavian and
CCA
• Arches upwards, forwards
laterally runs infront of vertibral
artery
• Arches above subclavian artery
passes between IJV and
ant.scalene
• Enters the junction of the left
subclavian and the IJV

49. CLINICAL CONSIDERATION THORACIC DUCT
 Injury to thoracic duct may lead to Chyle leak
 Chyle extravasation can result in
• delayed wound healing
• dehydration
• malnutrition
• electrolyte disturbances
• immunosuppression
o Prompt identification and treatment of a chyle leak
are essential for optimal surgical outcome

50. CLINICAL CONSIDERATION THORACIC DUCT
 Intraoperative Diagnosis of Chyle leak-
• Maneuvers that increase intrathoracic or intra-abdominal
pressure may facilitate the identification of a CL as well.
• Trendelenburg positioning and Valsalva maneuver while the
anesthesiologist applies positive pressure to raise
intrathoracic pressure
• manual abdominal compression
• Can propagate hydrostatic forces through the course of the
thoracic duct to increase chyle flow
• Distend the distal thoracic duct to improve visibility.

51. CLINICAL CONSIDERATION THORACIC DUCT
 Management- intraoperative Chyle leak
• Thoracic duct may be ligated with surgical clips or
nonabsorbable suture.
• Locoregional flaps may be incorporated for additional
coverage of the surgical bed.
• The clavicular head of the sternocleidomastoid can be
dissected free and sutured to the wound bed

52. CLINICAL CONSIDERATION THORACIC DUCT
 Postoperative Diagnosis of Chyle leak-
• Increases in drain output, especially following resumption of
feedings that contain fat .
• Neck may exhibit erythema, lymphedema, or a palpable fluid
collection in the supraclavicular region.
• Creamy or milky drain contents.
• Drain fluid with triglyceride level >100 mg/dL

53. CLINICAL CONSIDERATION THORACIC DUCT
 Management- Postoperative Diagnosis of Chyle
leak-
• Activity
• Diet
• Wound care
• Surgical reexploration

54. LEVELS OF LYMPH NODES

55. LEVELS OF LYMPH NODES

57. 68
CLASSIFICATION OF NECK
DISSECTIONS

58. CLASSIFICATION OF NECK DISSECTIONS
61
• Academy’s Committee for Head and Neck
Surgery and Oncology publicized standard
classification system

59. CLASSIFICATION OF NECK DISSECTIONS
62
• Academy’s classification
– 1) Radical neck dissection (RND)
– 2) Modified radical neck dissection (MRND)
– 3) Selective neck dissection (SND)
• Supra-omohyoid type
• Lateral type
• Posterolateral type
• Anterior compartment type
– 4) Extended radical neck dissection

60. CLASSIFICATION OF NECK DISSECTIONS
63
• Medina classification (1989)
– Comprehensive neck dissection
• Radical neck dissection
• Modified radical neck dissection
– Type I (XI preserved)
– Type II (XI, IJV preserved)
– Type III (XI, IJV, and SCM preserved)
– Selective neck dissection

61. CLASSIFICATION OF NECK DISSECTIONS
• Spiro’s classification
– Radical (4 or 5 node levels resected)
• Conventional radical neck dissection
• Modified radical neck dissection
• Extended radical neck dissection
• Modified and extended radical neck dissection
– Selective (3 node levels resected)
• SOHND
• Jugular dissection (Levels II-IV)
• Any other 3 node levels resected
– Limited (no more than 2 node levels resected)
• Paratracheal node dissection
• Mediastinal node dissection
• Any other 1 or 2 node levels resected

62. RADICAL NECK DISSECTION
65
Definition-
All lymph nodes in Levels I-V
including spinal accessory nerve
(SAN), SCM, and IJV
Indications-
Extensive cervical involvement
or matted lymph nodes with
gross extracapsular spread and
invasion into the SAN, IJV, or
SCM
–

63. MODIFIED RADICAL NECK DISSECTION
66
• Type I:Preservation of SAN
• Type II: Preservation of SAN
and IJV
• Type III: Preservation of SAN,
IJV, and SCM ( “Functional
neck dissection”)

64. SELECTIVE NECK DISSECTIONS
68
• Definition
– Cervical lymphadenectomy with preservation of one
or more lymph node groups
– Four common subtypes:
• Supraomohyoid neck dissection
• Posterolateral neck dissection
• Lateral neck dissection
• Anterior neck dissection

65. SND: SUPRAOMOHYOID TYPE
• Most commonly performed
SND
• Definition
– En bloc removal of cervical
lymph node groups I-III
– Posterior limit is the
cervical plexus and
posterior border of the
SCM
– Inferior limit is the omohyoid
muscle overlying the IJV

66. SND: SUPRAOMOHYOID TYPE
70
• Indications
– Oral cavity carcinoma
• Subsites - Lips, buccal mucosa, upper and lower alveolar
ridges, retromolar trigone, hard palate, and anterior 2/3s of
the tongue and FOM
– Bilateral SOHND
• Anterior tongue
• Oral tongue and FOM that approach the midline
– SOHND + parotidectomy
• Cutaneous SCCA of the cheek
• Melanoma (Stage I – 1.5 to 3.99mm) of the cheek

67. SND: LATERAL TYPE
71
• Definition
– En bloc removal of the jugular lymph
nodes including Levels II-IV
• Indications
– N0 neck in carcinomas of the
oropharynx, hypopharynx,
supraglottis, and larynx

68. SND: POSTEROLATERAL TYPE
• Definition
– En bloc excision of lymph bearing tissues in Levels II-IV and
additional node groups – suboccipital and postauricular
• Indications
– Cutaneous malignancies
• Melanoma
• Squamous cell carcinoma
• Merkel cell carcinoma
– Soft tissue sarcomas of the scalp and neck

69. SND: ANTERIOR COMPARTMENT
• Definition
– En bloc removal of lymph structures in Level VI
• Perithyroidal nodes
• Pretracheal nodes
• Precricoid nodes (Delphian)
• Paratracheal nodes along recurrent nerves
• Indications
– Selected cases of thyroid carcinoma
– Parathyroid carcinoma
– Subglottic carcinoma
– Laryngeal carcinoma with subglottic extension
– CA of the cervical esophagus

70. EXTENDED NECK DISSECTION
• Definition
– Any previous dissection which includes removal of one or more
additional lymph node groups and/or non-lymphatic structures.
– Usually performed with N+ necks in MRND or RND when
metastases invade structures usually preserved
• Indications
– Carotid artery invasion
– Other examples:
• Resection of the hypoglossal nerve resection or digastric
muscle,
• dissection of mediastinal nodes and central compartment
for subglottic involvement
• removal of retropharyngeal lymph nodes for tumors originating in
the pharyngeal walls.

71. REFERENCES
• Gray H. Anatomy Descriptive and Surgical:(" Gray's
Anatomy"). Classics of Medicine Library; 1981
• Netter FH. Atlas of Human Anatomy, Saunders Elsevier,
2014: Atlas of Human Anatomy. Bukupedia; 2014 Nov 14
• Textbook of Surgical Anatomy- Hollingshead
• Shah JP, Johnson NW, Batsakis JG. Oral cancer. CRC Press;
2002 Dec 19
• Press CR. Stell & Maran's textbook of head and neck surgery
and oncology. CRC Press; 2011 Dec 30

72. THANK YOU