Neck Dissection

Neck Dissection

Eric MeenNov. 30 2009

Contents• Neck anatomy• Levels of the neck• Classification of neck dissection– Radical neck dissection– Modified radical neck dissection– Selective neck dissection– Extended neck dissection

• Staging• Sequelae of neck dissection• Complications of neck dissection

Levels of the neck

• IA: Submental• IB: Submandibular• II: Upper jugular nodes• III: Middle jugular nodes• IV: Lower jugular nodes• V: Posterior triangle• VI: Central/anterior

compartment

Boundaries

• IA: submental– Superior

• Symphysis

– Inferior• Body of hyoid

– Medial• Anterior belly of

contralateral digastric

– Lateral• Anterior belly of

ipsilateral digastric

Boundaries

• IA: submental• Nodal spread from– Floor of mouth– Anterior oral tongue– Anterior lower alveolus– Lower lip

Boundaries

• IB: submandibular– Superior

• Body of mandible

– Inferior• Posterior belly of digastric

– Anterior• Anterior belly of digastric

– Posterior• Stylohyoid muscle

Boundaries

• IB: submandibular• Nodal spread from– Oral cavity– Anterior nasal cavity– Soft-tissue structures of

midface and submandibular gland

Boundaries• II: upper jugular

– Superior• Skull base

– Inferior• Horizontal plane defined by

the inferior body of the hyoid (clinical landmark)

• Carotid bifurcation (surgical landmark)

– Anterior• Stylohoid muscle

– Posterior• Posterior border of SCM

– CN XI divides level into IIA and IIB

Boundaries

• II: upper jugular• Nodal spread from– Oral cavity– Nasal cavity– Nasopharynx– Oropharynx– Hypopharynx– Larynx– Parotid

Boundaries• III: middle jugular

– Superior• Horizontal plane defined by

inferior body of hyoid (clinical landmark)

• Carotid bifurcation (surgical landmark)

– Inferior• Horizontal plane defined by

inferior border of cricoid (clinical landmark)

• Junction of omohyoid and IJV (surgical landmark)

– Anterior• Lateral border of sternohyoid

– Posterior• Posterior border of SCM

Boundaries

• III: middle jugular• Nodal spread from– Oral cavity– Nasopharynx– Oropharynx– Hypopharynx– Larynx

Boundaries• IV: lower jugular

– Superior• Horizontal plane defined by

inferior border of cricoid (clinical landmark)

• Junction of omohyoid and IJV (surgical landmark)

– Inferior• Clavicle

– Anterior• Lateral border of

sternohyoid– Posterior

• Posterior border of SCM

Boundaries

• IV: lower jugular• Nodal spread from– Hypopharynx– Thyroid– Cervical esophagus– Larynx

Boundaries• V: posterior triangle

– Superior• Apex of convergence of SCM and

trapezius– Inferior

• Clavicle– Anterior

• Posterior border of SCM– Posterior

• Anterior border of trapezius– Horizontal plane defined by

lower border of cricoid divides level into VA + VB

– Three lymphatic pathways• Nodes following XI as it traverses

posterior triangle• Nodes following transverse cervical

artery• Supraclavicular nodes (including

Virchow’s node)

Boundaries

• V: posterior triangle• Nodal spread from– Nasopharynx– Oropharynx– Cutaneous structures of

posterior scalp and neck– Thyroid– Virchow

• Any GI• Breast

Boundaries• VI: central compartment

– Superior• Hyoid bone

– Inferior• Suprasternal notch

– Medial• Contralateral carotid

– Lateral• Ipsilateral carotid

– Nodes involved• Pre and paratracheal• Precricoid (Delphian)• Perithyroidal

Boundaries

• VI: central compartment

• Nodal spread from– Thyroid– Glottic and subglottic

larynx– Apex of piriform sinus– Cervical esophagus

Division into subzones• Recommended in 2001 by American Head and Neck Society• Based on biological significance• Level I/IA/IB

– Unnecessary to dissect IA unless primary involves FOM, lip, structures of anterior midface, or if obvious lymphadenopathy present

• Level II/IIA/IIB– Risk of nodal disease in sublevel IIB is less in primaries of the oral

cavity and laryngeal than those in oropharynx– If no clinical nodal disease in level IIA in oral cavity and larynx,

unnecessary to dissect level IIB (which has high morbidity)• V/VA/VB

– Superior component: spinal accessory lymph nodes– Inferior component: Transverse cervical and supraclavicular nodes

• Carry a more dire prognosis when positive for H+N cancers

Radiologic boundaries

• Levels IB and IIA separated– Anatomic: by stylohyoid muscle– Radiographic: by transverse line drawn at

posterior surface of submandibular gland on each side of the neck

• Levels VI and III/IV– Anatomic: lateral border of sternohyoid muscle– Radiographic: common carotid or ICA

Neck dissection classificationTable 116-1 – Classification of neck dissection

1991 classification 2001 classification

Radical neck dissection Radical neck dissection

Modified radical neck dissection Modified radical neck dissection

Selective neck dissection Selective neck dissection: each variation depicted by “SND” and the use of parentheses to denote the levels or sublevels removed

• Supraomohyoid • SND (I-III/IV)

• Lateral • SND (II-IV)

• Posterolateral • SND (II-V, postauricular, suboccipital)

• Anterior • SND (VI)

Extended neck dissection Extended neck dissection

Comprehensive neck dissection:• Any neck dissection addressing level I-V on one side

• Radical neck dissection• Modified radical neck dissection

Neck dissection classification

• Radical neck dissection– En bloc removal of the lymph-node bearing tissue

of one side of the neck (levels II-V)– Borders:• Inferior border of mandible to clavicle; from lateral

border of the strap muscles to the anterior border of trapezius• Resection includes

– Accessory nerve– SCM– IJV

Radical neck dissection

• Indications– Extensive lymph node

metastasis– Extracapsular spread– Nodes involving XI or IJV– Many would say a

modified RND is as suitable in these cases

– Surgical violation of involved LNs should not be risked for purpose of structure preservation

Neck dissection classification• Modified radical neck dissection

– En bloc removal of the lymph-node bearing tissue of one side of the neck (levels II-V)

– Borders:• Inferior border of mandible to clavicle; from lateral border of the strap

muscles to the anterior border of trapezius

– Preservation of one or more of• Spinal accessory nerve• IJV• SCM

– Purpose• Significantly decreased morbidity

– Especially with preservation of XI

Modified radical neck dissection

Modified radical neck dissection• Notation– Previously

• MRND type 1: preservation of XI• MRND type 2: preservation of XI and IJV• MRND type 3: preservation of XI, IJV, SCM

– Currently• “MRND with preservation of x”

• Indications (same as RND)– Extensive lymph node metastasis– Extracapsular spread– Nodes involving XI or IJV

Neck dissection classification• SND (I-III)

(supraomohyoid neck dissection)

• SND (I-IV) (extended supraomohyoid neck dissection

• SND (II-IV) (lateral neck dissection)

• SND (II-V, post-auricular, suboccipital nodes) (posterolateral neck dissection)

Neck dissection classification

• Extended neck dissection– Any of the previously-mentioned neck dissections plus

• Lymph node groups that are not routinely removed– Retropharyngeal, suboccipital, upper mediastinal

• Other structure not routinely involved– Skin– Carotid artery– Levator scapulae– Vagus– Hypoglossal– Etc.

Selective neck dissection• Performed for patients at risk for early lymph node metastasis• Levels removed depends on the site of the primary tumor

– Based on known pattern of nodal spread• Elective neck dissection

– Remove at-risk areas, while avoiding risks associated with areas not likely to harbor occult mets

– Traditionally, indicated if chance of occult mets exceeds 20%• Staging neck dissection

– Allows histolopathologic staging of clinically and radiographically negative necks

– May demonstrate when post-operative RT indicated• Multiple positive nodes• Extracapsular spread neck dissection contents

Selective neck dissection for oral cavity cancer

• Oral cavity subsites– Lip– Alveolar ridge– Oral tongue– Retromolar trigone– Floor of mouth– Buccal mucosa– Hard palate

Selective neck dissection for oral cavity cancer

• SND (I-III) indicated for all sites– Except oral tongue (SND (I-IV)) due to skip metastases

• If N+ neck– Usually necessary to include IV and V (ie comprehensive neck

dissection)– Exception:

• If nodal disease confined to levels I and II, SND (I-IV) is appropriate– Elective SND of the contralateral neck indicated if primary of

• Floor of mouth• Anterior/midline oral tongue• Tumor approaches midline

• If N+ bilaterally– Bilateral comprehensive neck dissections

Treatment of N0 neck by subsite(finer details for seniors)

• Lip:– If primary is bulky (>3cm)– Tumor thickness >5mm– Poor differentiation– Perineural invasion present

• Alveolar ridge:– For T3 and T4 primaries– Poor differentiation

• Oral tongue– If depth >2mm– If anterior, or near midline, treat bilaterally

Treatment of N0 neck by subsite(finer details for seniors)

• Retromolar trigone– SND indicated in all cases

• Floor of mouth– Some sources:

• All T2-4 primaries, and T1 with poor differentiation– Other sources

• SND if depth of primary >2mm– Treat bilaterally

• Buccal mucosa– SND indicated in all cases

• Hard palate– “None” vs. SND for T4 primaries

Selective neck dissection for oropharyngeal, hypopharyngeal, and laryngeal cancer

• SND (II-IV)• Level IIB may be excluded for laryngeal and hypopharyngeal

primaries• Larynx– Supraglottis

• Very rich bilateral lymphatic drainage• B/L SND

– Glottis• Poor lymphatic drainage• SND in bulky T4 disease

– Subglottis• Bilateral SND in advanced disease

– Transglottic• Bilateral SND


• Oropharynx– All T2-4 lesions require treatment of neck– Bilateral SND if• Clinical disease on one side of the neck• Lesion is central• Lesion crosses midline

– Retropharyngeal lymph nodes must be addressed either surgically or with RT


• Hypopharynx– Very rich lymphatic drainage– All require bilateral treatment of neck• Only possible exception: very early lesions, where

unilateral treatment of neck may be acceptable

– SND (II-IV) vs. RT• Based on which modality used to treat primary

Selective neck dissection for cutaneous malignancies

• Posterior scalp and upper neck– SND (II-V, postauricular,

suboccipital) (ie extended neck dissection)

• Anterior scalp, preauricular, temporal regions– SND (parotid and facial

nodes, IIA, IIB, III, VA)• Anterior and lateral face

– SND (parotid and facial nodes, I-III)

Selective neck dissection for cancer of midline structures of anterior lower neck

• SND (VI) +/- other neck levels indicated in– Thyroid cancer– Advanced glottic and subglottic cancer– Advanced piriform sinus cancer– Cervical esophageal and tracheal cancer

Selective neck dissection for other sites

• Salivary gland neoplasms– SND (I-III) if

• Primary >4cm• SCC• Adenocarcinoma• Undifferentiated carcinoma• High-grade mucoepidermoid carcinoma

• Melanoma– Elective SND not indicated

• Paranasal sinuses, nasal cavity– Elective SND not indicated

General algorithm

Nodal staging• Features of positive nodes

– Size:• Jugulodigastric: 1.5 cm or bigger• All others: 1.0 cm or bigger

– Presence of central necrosis• Nx: regional lymph nodes can not be assessed• N0: no regional lymph node metastasis• N1: metastasis in a single ipsilateral lymph node, 3 cm or less in greatest

dimension• N2a: metastasis in a single ipsilateral lymph node more than 3 cm but not

more than 6 cm in greatest dimension• N2b: metastasis in multiple ipsilateral lymph nodes, none more than 6 cm

in greatest dimension• N2c: metastasis in bilateral or contralateral nodes no more than 6 cm in

greatest dimension• N3: Metastasis in a lymph node more than 6 cm in greatest dimension

Nodal staging

• Staging in nasopharyngeal carcinoma– Different distribution of nodal spread– Different prognostic impact of nodal disease

• Nx and N0: same• N1: unilateral metastasis in lymph node(s), 6 cm or less

in greatest dimension, above the supraclavicular fossa• N2: Bilateral metastasis in lymph node(s), 6 cm or less

in greatest dimension, above the supraclavicular fossa• N3a: Greater than 6 cm in dimension• N3b: extension to the supraclavicular fossa

Prognosis

• 5 year survival for H+N ca:

• Positive neck decreases 5-year survival by 50%

T1-2 T3-4

N- 80 40

N+ 40 20

Sequelae of neck dissection• Most notable sequela arises from removal of accessory

nerve in RND• Results in denervation of trapezius– Important shoulder abductor– Destabilization of scapula– Post neck dissection shoulder syndrome

• Pain• Weakness

– Unable to abduct shoulder above 30 degrees at the shoulder• Deformity

– Scapula flares– Droops– Rotates anterolaterally

Sequelae of neck dissection• Less shoulder dysfunction in nerve-sparing procedures• Function usually improves over 1 yr in nerve-sparing

procedures– Not so when nerve removed

• Some dysfunction often detectable after selective neck dissections

• Permanent dysfunction significantly compromises quality of life

• All patients undergoing neck dissection of any type should begin physiotherapy early in the post-operative course

Complications of neck dissection• Air leaks• Wound infection• Bleeding• Chylous fistula• Facial/cerebral edema• Blindness• Neural complications• Internal jugular rupture• Carotid artery rupture

Complications of neck dissection

• Air leaks– Circulation of air through a wound drain– Usually occurs POD 1– May be due to either improperly placed drain, or

incomplete closure– Occlusive dressing may prevent further leak– May represent communication with trach site or

mucosal suture line• Identify early• May require revision of wound closure in OR


• Bleeding– Bleeding through incision: often due to

subcutaneous blood vessel• Often controllable with ligation

– Hematoma• Swelling or ballooning of skin flaps• Milking drains may result in evacuation of blood• If blood reaccumulates quickly, return to the OR• Failure to drain hematoma may lead to wound

infection

Complications of neck dissection• Chylous fistula– Usually identified and treated intraoperatively

• Valsalva– Post-op chylous fistula occurs in 1-2 % of neck dissections– Management

• Intraoperative – if– Noted immediately post-op– Daily drainage > 600 cc

• Conservative– Leak apparent after enteral feeds resumed– Drainage < 600 cc/day– Manage with closed wound drainage, pressure dressings, medium-chain

fatty acid diet– TPN may be necessary for high-output or intractable fistulas

Complications of neck dissection• Facial/cerebral edema

– As a result of bilateral IJV ligation• Facial edema

– May be preventable by preserving at least one EJV• Cerebral edema

– May be the cause of impaired neurologic function and coma that occur after bilateral RND

– Bilateral ligation of IJV leads to increased ICP• May lead to SIADH (it does in dog studies)• Vicious cycle:

– The resulting expansion of extracellular fluids and dilutional hyponatremia aggravate the cerebral edema

• Any patient undergoing bilateral IJ ligation requires careful peri- and post-operative monitoring of fluid status and electrolyte balance


• Blindness– Rare• Only 5 cases ever reported• But all texts list it as a complication• Due to hypotension leading to optic nerve infarction?


• Neural injury– Lingual nerve– Marginal mandibular nerve– Vagus nerve

• Superior laryngeal• RLN

– XI– Hypoglossal– Phrenic– Sensory nerves


• Jugular vein rupture– Rare– Present with multiple usually small bleeding

episodes– Life-threatening bleeding may occur– Requires surgical exploration and ligation of vein

Complications of neck dissection• Carotid artery rupture

– Rarely occurs in absence of pharyngocutaneous fistula– Factors predisposing to rupture

• Long exposed segment• Large cutaneous defect• Large, high-output fistulas

– In these cases, return to OR and cover carotid with well-vascularized tissue

– In event of rupture• Blowout usually near carotid bulb and pinpoint in size• Manual pressure• Fluids and blood• Return to the OR

– Expose and ligate carotid proximally and distally– Attempts to repair area of rupture “futile”

Summary• Neck anatomy• Levels of the neck• Classification of neck dissection– Radical neck dissection– Modified radical neck dissection– Selective neck dissection– Extended neck dissection

• Staging• Sequelae of neck dissection• Complications of neck dissection

Documents

Neck Dissection