Structure Preserved in Radical Neck Dissection
In a radical neck dissection, none of the structures listed in the options are preserved. Radical neck dissection involves the removal of all lymph node groups (levels I-V), along with the internal jugular vein, sternocleidomastoid muscle, spinal accessory nerve, and submandibular salivary gland. 1
Understanding Radical Neck Dissection
Radical neck dissection is the most extensive form of neck dissection, originally described by Crile in the early 20th century and later refined by Martin 2. It involves complete removal of:
- All lymph node groups (levels I-V)
- Internal jugular vein
- Sternocleidomastoid muscle
- Spinal accessory nerve
- Submandibular salivary gland
This procedure is typically reserved for patients with extensive nodal disease (N3) 1.
Modified and Selective Neck Dissections
Due to the significant morbidity associated with radical neck dissection, modifications have been developed:
Modified radical neck dissection: Preserves one or more of the non-lymphatic structures (internal jugular vein, sternocleidomastoid muscle, spinal accessory nerve) while still removing all lymph node groups (levels I-V) 1, 3
Selective neck dissection: Removes only specific lymph node groups at highest risk for metastases based on the primary tumor site 1
Clinical Implications and Functional Outcomes
The removal of critical structures in radical neck dissection leads to significant functional impairments:
- Removal of the spinal accessory nerve causes shoulder dysfunction and pain 4
- Removal of the sternocleidomastoid muscle results in neck contour deformity 4
- Removal of the internal jugular vein may cause facial edema and increased intracranial pressure 4
- Removal of the submandibular gland affects salivary production 1
Anatomical Considerations
The posterior belly of the digastric muscle serves as an important surgical landmark during neck dissection, helping to define boundaries of the carotid, submandibular, and submental triangles 5, 6. However, in radical neck dissection, this structure is typically not specifically preserved, though it may not be routinely removed unless involved by tumor.
Current Practice
Modern head and neck surgical oncology has largely moved away from radical neck dissection in favor of modified radical or selective neck dissections when oncologically appropriate, as these procedures achieve equivalent disease control with significantly less morbidity 1, 2.