What are the different types of neck dissection?

Types of Neck Dissection

Neck dissections are primarily classified as either comprehensive or selective, with the choice depending on the extent of nodal disease, primary tumor site, and patient factors. 1

Comprehensive Neck Dissection

A comprehensive neck dissection removes all lymph node groups that would be included in a classic radical neck dissection (levels I-V). Key characteristics include:

• Removes all five lymph node levels
• May preserve or sacrifice non-lymphatic structures (sternocleidomastoid muscle, jugular vein, spinal accessory nerve)
• Whether these structures are preserved does not affect the classification as comprehensive 1
• Typically recommended for patients with positive nodal disease, particularly N3 disease 1

Selective Neck Dissection

Selective neck dissection removes only specific lymph node groups that are at highest risk for metastases based on the primary tumor site:

• Oral Cavity: Levels I-III (sometimes including superior parts of level V) 1
• Oropharynx: Levels II-IV 1
• Hypopharynx: Levels II-IV and level VI when appropriate 1
• Larynx: Levels II-IV and level VI when appropriate 1

Selective neck dissections are typically performed for:

• N0 disease (clinically negative neck)
• Cases with low neck tumor burden 1
• When access to vessels is needed for microvascular anastomosis for free flaps 1

Extended Neck Dissection

Extended neck dissection goes beyond the boundaries of a comprehensive neck dissection to include additional structures not typically removed in standard procedures:

• May include removal of additional lymph node groups (e.g., parapharyngeal, superior mediastinal, paratracheal, retropharyngeal)
• May include removal of non-lymphatic structures such as skin, carotid artery, vagus nerve, hypoglossal nerve, etc. 2
• Typically performed for advanced nodal disease (N2, N3) with extranodal extension 2

Lymph Node Levels

Understanding lymph node levels is crucial for proper neck dissection planning:

• Level I: Submental and submandibular nodes
• Level II: Upper jugular nodes
• Level III: Middle jugular nodes
• Level IV: Lower jugular nodes
• Level V: Posterior triangle nodes
• Level VI: Central compartment nodes (prelaryngeal, pretracheal, paratracheal)

Clinical Decision-Making

The type of neck dissection is determined by:

1. Nodal Status:

   • N0: Selective neck dissection 1
   • N1-N2a-c: Selective or comprehensive neck dissection 1
   • N3: Comprehensive neck dissection 1

2. Primary Tumor Site:

   • Different primary sites drain to predictable lymph node levels, guiding the extent of dissection 1
   • Tumors with bilateral lymphatic drainage (base of tongue, palate, supraglottic larynx) may require bilateral neck dissections 1

3. Extranodal Extension:

   • Presence of extracapsular spread indicates more aggressive disease and may warrant more extensive dissection 3

Important Considerations

• Histologic examination of a selective neck dissection specimen typically includes 6 or more lymph nodes 1
• Histologic examination of a radical or modified radical neck dissection specimen typically includes 10 or more lymph nodes 1
• Most masses greater than 3 cm in diameter are not single lymph nodes but represent confluent nodes or tumor in soft tissues 1, 3
• Selective neck dissection has evolved from being primarily a staging procedure to having therapeutic value in selected patients with nodal disease 4

Potential Complications

• Comprehensive neck dissections are associated with greater morbidity than selective dissections 5
• Complications may include shoulder dysfunction (when accessory nerve is sacrificed), lymphedema, cosmetic deformity, and wound healing issues 1
• Salvage neck dissection after prior treatment carries increased risk of complications including delayed wound healing, skin necrosis, and carotid exposure 1

By understanding these different types of neck dissection and their indications, surgeons can select the appropriate procedure that balances oncologic control with minimizing morbidity for each individual patient.