Structure Preserved in Radical Neck Dissection
None of the listed structures are preserved in a radical neck dissection. In a radical neck dissection, all of the following structures are removed: internal jugular vein, sternocleidomastoid muscle, spinal accessory nerve, submandibular salivary gland, and lymph node groups (levels I-V). 1
Understanding Radical Neck Dissection
Radical neck dissection is a comprehensive surgical procedure for treating head and neck cancer that involves complete removal of:
- Internal jugular vein
- Sternocleidomastoid muscle
- Spinal accessory nerve
- Submandibular salivary gland
- All lymph node groups (levels I-V)
This procedure was first described by Crile in the early 20th century and was later refined by Martin 2. It represents the most extensive form of neck dissection and is typically reserved for patients with extensive nodal disease (N3) 1.
Types of Neck Dissection
It's important to distinguish between the different types of neck dissection:
Radical Neck Dissection: Removes all lymph node groups (I-V) along with the internal jugular vein, sternocleidomastoid muscle, spinal accessory nerve, and submandibular salivary gland 1, 3
Modified Radical Neck Dissection: Preserves one or more of the non-lymphatic structures (internal jugular vein, sternocleidomastoid muscle, or spinal accessory nerve) while still removing all lymph node groups 1, 2
Selective Neck Dissection: Removes only specific lymph node groups at highest risk for metastases based on the primary tumor site 1
Clinical Implications
The radical neck dissection has significant functional implications:
- Removal of the spinal accessory nerve leads to shoulder dysfunction
- Loss of the sternocleidomastoid muscle causes cosmetic deformity
- Excision of the internal jugular vein may lead to increased intracranial pressure
- Removal of the submandibular gland affects salivary production
These functional deficits have led to the development of modified approaches that preserve key structures when oncologically safe to do so 3, 2.
Anatomical Considerations
The posterior belly of the digastric muscle serves as an important landmark during neck dissection, helping to define boundaries of the carotid, submandibular, and submental triangles 4. However, in a radical neck dissection, this structure is not specifically preserved as the focus is on complete removal of all lymphatic tissues and the aforementioned non-lymphatic structures.
Current Practice
While radical neck dissection was once the standard of care, current practice has evolved toward more selective approaches when appropriate. Modified radical neck dissection, which preserves one or more of the non-lymphatic structures, is now more commonly performed when oncologically feasible 2, 5. This evolution in surgical technique aims to reduce morbidity while maintaining oncologic efficacy.