neck dissection
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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
Classification of NeckDissections
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).
Classification of NeckDissections
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.
Classification of NeckDissections
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
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