neck dissection

Neck Dissections:Classifications,

Indications, & Techniques

INTRODUCTION

Neck dissection is performed for the surgical control of metastatic neck disease in patients with squamous cell carcinomas of the upper aerodigestive tract, salivary gland tumors, and skin cancer of the head and neck (including melanomas).

Neck dissection is also indicated for the surgical control of metastatic carcinoma to the neck when the nasopharynx and thyroid are the primary sites.

Evolution of the neck dissection 1880 – Kocher proposed removing nodal metastases 1906 – George Crile described the classic radical neck dissection (RND) 1933 and 1941 – Blair and Martin popularized the RND

1953 – Pietrantoni recommended sparing the spinal accessory nerves

Evolution of the neck dissection

1967 - Bocca and Pignataro described the

“functional neck dissection” (FND)

1975 – Bocca established oncologic safety

of the FND compared to the RND

1989, 1991, and 1994 – Medina, Robbins,

and Byers respectively proposed

classifications of neck dissections

Evolution of the neck dissection

1991 – Official Report of the ‘Academy’s Committee for Head and Neck Surgery and Oncology’ standardized neck dissection terminology

Surgical Anatomy

Fascial layers of the neck Superficial cervical fascia

Deep cervical fascia– Superficial layer (investing

layer) SCM, strap muscles, trapezius

– Middle or Visceral Layer

(pretracheal fascia) Thyroid Trachea Esophagus

– Deep layer (prevertebral

fascia) Vertebral muscles Phrenic nerve Cervical & Brachial Plexus

MUSCLES Platysma SCM Omohyoid Trapezius Digastric

MUSCLES Platysma

Surgical considerations– Increases blood supply to

skin flaps– Absent in the midline of the

neck– Fibers run in an opposite

direction to the SCM

SCM

Surgical considerations– Overlies IJV, Has to be

retracted laterally to exposes LN related to IJV

MUSCLES 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

Trapezius

Surgical considerations Posterior limit of Level V neck

dissection Denervation results in shoulder

drop and winged scapula

MUSCLES Digastric

Surgical considerations Posterior belly is superficial

to: ECA Hypoglossal nerve ICA IJV Anterior belly Landmark for identification of

mylohyoid m. for dissection of the submandibular triangle

NERVES Marginal Mandibular Nerve

Should be preserved in neck dissections

• Most commonly injured while dissection at level Ib

• Found: – 1cm anterior and inferior to

angle of mandible – Deep to fascia of the

submandibular gland (superficial layer of deep

cervical fascia) – Superficial to adventitia of

the facial vein

NERVESSpinal Accessory Nerve

Penetrates the deep surface of the SCM

Exits posterior surface of SCM deep to Erb’s point

Traverses the posterior triangle ensheathed by the superficial cervical fascia and lies on the levator scapulae

Enters the trapezius approx. 5 cm above the clavicle

Spinal Accessory Nerve

CN XI – Relationship with the IJV

NERVES Phrenic Nerve

Sole nerve supply to the diaphragm

Supplied by nerve roots C3-5

Runs obliquely toward midline on the anterior surface of anterior scalene

Covered by prevertebral fascia

Lies posterior and lateral to the carotid sheath

NERVESHypoglossal nerve

Lies deep to the IJV, ICA, CN IX, X, and XI

Curves 90 degrees and passes between the IJV and ICA

Surrounded by venous plexus (ranine veins)

Iatrogenic injury – Most common site - floor of the

submandibular triangle, just deep to the duct

– Ranine veins

Thoracic duct Conveys lymph from the entire

body back to the blood

– Exceptions: Right side of head and neck, Rt. U

Ext, right lung right heart and portion of the liver

– Begins at the cisterna chyli

– Enters posterior mediastinum between the azygous vein and

thoracic aorta

– Courses to the left into the neck anterior to the vertebral column.

–Enters the junction of the left subclavian and the IJV

Thoracic duct

Staging of the

Neck nodes

Staging of the neck nodes

“N” classification – AJCC (1997) Consistent for all mucosal sites except the

nasopharynx. Nasopharynx and Thyroid have different

staging based on tumor behavior and prognosis.

Based on extent of disease prior to first treatment.

Staging of the neck nodes--NxNx- Can not be assessed -- Can not be assessed -N0N0- No lymph node metastasis- No lymph node metastasis--N1N1- Single, ipsilateral, <3cm -- Single, ipsilateral, <3cm -N2N2- Single, ipsilateral 3-6 cm or- Single, ipsilateral 3-6 cm or multiple <6 cmmultiple <6 cm *N2a- single, ipsilateral 3-6 cm*N2a- single, ipsilateral 3-6 cm

*N2b- multiple, ipsilateral none >6 cm*N2b- multiple, ipsilateral none >6 cm *N2c- contra lateral/ bilateral, none >6 cm*N2c- contra lateral/ bilateral, none >6 cm

--N3N3- > 6cm- > 6cm

Lymph Node

Levels/Nodal

Regions

Lymph Node Subzones

Lymph node levels/Nodal regions Level I: Submental & Submandibular.

Levels II, III, IV: nodes associated with IJV within fibroadipose tissue (posterior border of SCM and lateral border of sternohyoid).

Level II: Upper third jugular chain, Jugulodigastric, and upper posterior cervical nodes.

– Boundaries - hyoid bone (clinical landmark) or carotid bifurcation (surgical landmark)

Lymph node levels/Nodal regions Level III: Middle jugular nodes

– Boundaries - Inferior border of level II to cricothyroid notch (clinical landmark)

or omohyoid muscle (surgical landmark).

Level IV: Lower jugular nodes.

– Boundaries -inferior border of level III to clavicle.

Lymph node levels/Nodal regions

Level V: Posterior triangle of neck

– Boundaries - posterior border of SCM, clavicle, and anterior border of trapezius.

Level VI: Anterior compartment structures.

– Boundaries - Hyoid, supra sternal notch, medial border of carotid sheath)

Level VII: Ant. mediastinal

Classification of Neck Dissections

Classification of NeckDissections

Academy’s classification1) 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


Academy’s classification – Based on 4 concepts.

1) RND is the standard basic procedure for cervical lymphadenectomy against which all other modifications are compared.

2) Modifications of the RND which include preservation of any non-lymphatic structures are referred to as modified radical neck dissection (MRND).


Academy’s classification

3) Any neck dissection that preserves one or more groups or levels of lymph nodes is referred to as a selective neck dissection (SND).

4) An extended neck dissection refers to the removal of additional lymph node groups or non-lymphatic structures relative to the RND.


Medina classification (1989)

• 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.

Radical Neck Dissection

Definition

-All lymph nodes in Levels I-V including Spinal-accessory nerve (SAN), SCM, and IJV are removed.

EXTENT OF RADICAL NECK DISSECTION

The margins of the The margins of the dissectiondissection are are

Inferiorly- Inferiorly- the the clavicleclavicle

Superiorly- Superiorly- the the mandiblemandible

Posteriorly- Posteriorly- thethe anterior anterior border of the trapeziusborder of the trapezius

Anteriorly- Anteriorly- thethe lateral lateral border of the sternohyoid border of the sternohyoid musclemuscle..

Radical Neck Dissection

Indications

– Extensive cervical involvement or matted lymph nodes with gross extracapsular spread and invasion into the SAN, IJV, or SCM.

Modified Radical NeckDissection (MRND)

Definition

– Excision of same lymph node bearing regions as RND with preservation of one or more nonlymphatic structures (SAN, SCM, IJV)

– Spared structure specifically named.

– MRND is analogous to the “functional neck dissection” described by Bocca.

MRND- Rationale Lymphatics of neck- contained in fibroadipose

tissue within the aponeurotic partions c are separate from SCM and IJV.

Aponeurotic coverings can be stripped from these structure to preserve these.

SAC n. runs thro’ nodal bearing tissue of neck, can only be preserved if LN’s are not closly related to it.

EXTENT OF MODIFIED RADICAL NECK DISSECTION

Modified Radical NeckDissection

Three types

MRND TYPE I: Preservation of SAN

MRND TYPE II : Preservation of SAN and IJV

MRND TYPE III: Preservation of SAN, IJV, and SCM ( “Functional neck dissection”).

Selective Neck Dissections Definition

– Cervical lymphadenectomy with preservation of one or more lymph node groups

RATIONALE:

– SND is designed to remove cervical lymph nodes at risk of involvement by metastatic cancer, which is based on site of primary cancer.

–The basic anatomic studies have demonstrated that lymphatic drainage of mucosal sites of head and neck follow relatively constant and predictable routes.

Selective Neck Dissections Four common subtypes:

• Supraomohyoid neck dissection (SO)

• Posterolateral neck dissection (PL)

• Lateral neck dissection (L)

• Anterior neck dissection (A)

:

SND: Supraomohyoid type Most commonly performed

SND Definition

– En-bloc removal of cervical lymph node groups I-III

– Posterior limit is the post. border of the SCM

– Inferior limit is the omohyoid muscle overlying the IJV

Indications

– Oral cavity carcinoma with N0 neck

Extended supraomohyoid N D

In case of carcinoma of lateral border of tongue involvement of level IV L. N. is common, so level IV dissection should be done in such case.

SND: Lateral Type 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.

SND: Posterolateral Type Definition– En bloc excision of lymph

nodes in Levels II to V.

Indications– Cutaneous malignancies • Melanoma • Squamous cell Ca • Ca Thyroid • Merkel cell carcinoma– Soft tissue sarcomas of

the scalp and neck.

SND: Anterior Compartment Definition– En bloc removal of lymph structures Level VI • Peri thyroidal nodes • Pre tracheal nodes • Pre cricoid nodes (Delphian) • Para tracheal nodes along recurrent nerves.– Limits of the dissection are the hyoid bone,

suprasternal notch and carotid sheaths

Indications– Selected cases of thyroid carcinoma– Parathyroid carcinoma– Subglottic carcinoma– Laryngeal carcinoma with subglottic

extension– CA of the cervical esophagus

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- dissection of mediastinal nodes and central compartment for subglottic involvement, and - removal of retropharyngeal lymph nodes for tumors originating in the pharyngeal walls.

ANAESTHESIA AND POSITION

ANAESTHESIA –General Anaesthesia with ETT.

POSITION-Place the patient in the supine position with a shoulder roll extending the neck. Elevate the upper half of the operating table to a 30° angle.

INCISIONS

Can be performed through a number of incisions The decision to use a certain incision will be

based on a number of factors which include: Personal preference Previous radiotherapy Number of levels required to assess Site of the primary tumor if that is being resected

INCISIONS

Half Apron Incision

Apron Incision

INCISIONS

Conley Incision

Double-Y Incision

INCISIONS

H Incision

MacFee Incision

INCISIONS

Y Incision

Modified Schobinger Incision

OPERATIVE PROCEDURE

OPERATIVE PROCEDURE

The skin is prepared in the standard manner and the skin incision marked out using a marking pen

OPERATIVE PROCEDURE

Make the skin incision through the platysma and elevate the flap in the subplatysmal plane

OPERATIVE PROCEDURE

Identify and preserve the marginal mandibular nerve at the superior aspect of the flap.

Remove submental fatty tissue and displace it inferiorly

OPERATIVE PROCEDURE

Removal of Submental and pregladular Submandibular nodes

Removal of submandibular glands with duct and associated lymph nodes

OPERATIVE PROCEDURE Expose the

sternocleidomastoid muscle and incise it above the clavicle.

Identify the anterior and posterior belly of the omohyoid with transection of the omohyoid posteriorly

OPERATIVE PROCEDURE

Identify the internal jugular vein and vagus nerve in the lower aspect of the neck before ligation of the internal jugular vein. Further identify the carotid artery and the vagus nerve.

OPERATIVE PROCEDURE Open the supraclavicular

fatty tissue using blunt dissection, either with a finger or hemostat, with identification of the phrenic nerve and brachial plexus

Dissect from inferior to superior. Continue the dissection along the anterior border of the trapezius. Preserve the phrenic nerve and brachial plexus.

OPERATIVE PROCEDURE

Separate the surgical specimen from the carotid and vagus, proceeding superiorly, with identification of the hypoglossal nerve

OPERATIVE PROCEDURE

Cut the sternocleidomastoid muscle superiorly

Identify the internal jugular vein superiorly, medial to the posterior belly of the digastric muscle. Dissect and ligate

OPERATIVE PROCEDURE

OPERATIVE PROCEDURE

Irrigate with isotonic sodium chloride solution. Maintain hemostasis

OPERATIVE PROCEDURE Insert drains (0.125-in

Hemovac or Jackson-Pratt); usually, use 2 for each side of the neck.

Close the wounds in layers with 3-0 Vicryl through the platysmal flaps and skin with staples or 4-0 nylon.

Postoperative details: Maintain head elevation at a 30° angle.

Ensure that the Hemovacs or drains are functioning properly.

Ensure that drains are maintained on continuous suction until they drain less than 20-25 mL in 24 hours.

Monitor for fever, bleeding, or hematoma formation in the postoperative period.

Avoid atelectasis. Move the patient out of bed the day after surgery with assistance. Encourage deep breathing and early ambulation with assistance.

Monitor for possible fistula if the oral or upper digestive tract was opened, particularly during the third or fourth postoperative day.

Intraoperative Complications

Hemorrhage Carotid sinus reflux Pneumothorax Air embolus Nerve damage Chylous fistula

Postoperative Complications

Hematoma Wound infection Skin flap loss Salivary fistula Facial edema Carotid artery rupture

THANKS