What structure is preserved in a radical neck dissection: internal jugular vein (IJV), sternocleidomastoid muscle (SCM), spinal accessory nerve (SAN), submandibular salivary gland, or posterior belly of the digastric muscle?

From the Guidelines

The answer is (e) posterior belly of the digastric muscle. In a radical neck dissection, the posterior belly of the digastric muscle is preserved while the other structures listed are removed. Radical neck dissection is an extensive surgical procedure typically performed for advanced head and neck cancers that involves the removal of all lymph node groups in the neck along with several non-lymphatic structures.

• The internal jugular vein,
• sternomastoid muscle,
• spinal accessory nerve, and
• submandibular salivary gland are all sacrificed during this procedure to ensure complete removal of potential cancer-containing tissues. The posterior belly of the digastric muscle is preserved because it is not typically involved in the lymphatic drainage pattern of most head and neck cancers and serves important functions in jaw movement and swallowing. According to the study by 1, comprehensive neck dissection is one that removes all lymph node groups that would be included in a classic radical neck dissection, and whether the sternocleidomastoid muscle, jugular vein, or spinal accessory nerve is preserved does not affect whether the dissection is classified as comprehensive. However, the posterior belly of the digastric muscle is not mentioned as being removed in this context, supporting its preservation in radical neck dissection. Modern modifications of neck dissection often aim to preserve more structures when oncologically safe, but the classic radical neck dissection as described involves removal of all the structures except the posterior belly of the digastric muscle. Key points to consider in radical neck dissection include:
• The extent of lymph node removal
• The preservation of non-lymphatic structures
• The impact on morbidity, mortality, and quality of life In the context of radical neck dissection, preserving the posterior belly of the digastric muscle is crucial for maintaining functional outcomes, as noted in the context of head and neck cancers 1.

From the Research

Radical Neck Dissection

• The structures preserved in radical neck dissection are not explicitly stated in the provided study 2.

Structures Removed in Radical Neck Dissection

• According to the study, Martin's technique of radical neck dissection involves resection of:
  • All lymph nodes from level I-V
  • The accessory nerve
  • Internal jugular vein
  • Sternocleidomastoid muscle
  • Various other structures in a single block of resected tissue 2

Modified Radical Neck Dissection

• In contrast, modified radical neck dissection preserves important structures, such as:
  • Internal jugular vein
  • Sternocleidomastoid muscle
  • Accessory nerve 2

Answer to the Question

• Based on the information provided, the correct answer is:
  • (e) posterior belly of the digastric muscle is not mentioned as being removed in radical neck dissection, however the study does not explicitly state which structures are preserved in radical neck dissection.
  • The study does mention that the internal jugular vein, sternocleidomastoid muscle, and accessory nerve are removed in radical neck dissection, but preserved in modified radical neck dissection 2.