Neck Dissection
What the Examiner Expects
Systematic surgical removal of cervical lymph nodes for metastatic cancer, classified by the structures preserved and the nodal levels dissected. The examiner expects you to know the five levels of cervical lymph nodes, differentiate the three types of neck dissection (radical — removes all nodes plus SCM, IJV, and CN XI; modified radical — removes all nodes but preserves one or more of the three structures; selective — removes only the nodal levels at highest risk based on the primary tumor), and understand the indications (clinically or pathologically positive cervical lymph nodes from head and neck squamous cell carcinoma, thyroid cancer, melanoma, or other tumors).
Key Examiner Focus Points
- Radical: removes SCM, IJV, spinal accessory nerve (CN XI), and all five nodal levels
- Modified radical: preserves one or more non-lymphatic structures (SCM, IJV, CN XI)
- Selective: removes only specific nodal levels based on primary tumor location
- Spinal accessory nerve injury causes shoulder drop and inability to abduct arm above 90°
- Most common indication: cervical lymph node metastases from head and neck squamous cell carcinoma
Common Curveballs
During neck dissection, the thoracic duct is injured (left side, low neck)
Ligate the thoracic duct immediately — identify the duct at its entry point into the junction of the left subclavian and internal jugular veins. Clip or suture-ligate it. If missed, the patient develops a chylous leak (high triglyceride, milky drain output). Initial management: low-fat diet with medium-chain triglycerides, pressure dressing. If output > 500 mL/day for 5+ days, surgical re-exploration and ligation.
Bilateral modified radical neck dissection is planned — surgeon wants to ligate both IJVs
Bilateral IJV ligation causes severe facial/cerebral edema and increased intracranial pressure. NEVER ligate both IJVs simultaneously. If bilateral dissection is required, preserve at least one IJV. Stage the operations if needed.