14. Thyroidectomy
• Over the last century, from a dangerous and bloody undertaking to a
safe operation with favorable outcomes.
Benign and malignant conditions:
Thyroid nodules Hyperthyroidism Obstructive or substernal goiter
Differentiated (papillary or
follicular) thyroid cancer
Medullary thyroid cancer Anaplastic thyroid cancer
Metastases to the thyroid Primary thyroid lymphoma
Vocal fold dysfunction (VFD): temporary rate 9.8%, permanent rate 2.3% (meta analysis, 2009, over 25,000 patients)
14
15. Recommendation 2: The preoperative physical examination
should include voice assessment. (Strong recommendation, moderate-
quality evidence)
• Patients with preoperative hoarseness or voice changes
• Patients with history of prior neck or mediastinal surgery, both thyroid and nonthyroid
• Patients with extrathyroidal extension of tumor posteriorly
• Patients with bulky lymphadenopathy in the central compartment or jugular chain
15
17. Intraoperative Events cause VFD
• Intubation -> vocal fold laceration, hematoma, edema or rupture;
Arytenoid dislocation;
formation of chronic granuloma or polyp
• Thermal or traction-related nerve trauma (use of energy devices too
close to a nerve; unintentional clamping, ligation or transection);
• Nerve transection (intentional or rarely unintentional)
Excessive traction on the RLN or a thermal event are common mechanisms leading to paresis or paralysis and
May not always be recognized intraoperatively.
17
18. Intraoperative Assessment of Nerve
Function
• Traditional methods –
intraoperative visualization and
knowledge of the normal and
variant RLN anatomy.
• Recurrent Laryngeal nerve
monitoring –
preoperative planning
significant expertise
avoidance of neuromuscular
blockade after anesthetic induction
18
19. Challenging operations
• Reoperation with adhesion tissue, difficult anatomy
• Resection of large or substernal goiter, suspect RLN dislocation
• Resection of locally advanced thyroid cancer with central LN resection
• Unilateral VCD, lobectomy with the opposite side
19
21. Result of IONM application
Total RLN injury Transient injury Permanent injury
Overall meta-analysis + + +
Subgroup – bilateral
operation
+ + +
Subgroup – malignancy
operation
+ + -
Subgroup – reoperation - - -
Subgroup – operation
volume
+ + +
+ significant reduce the nerve injury; - no significant reduce the nerve injury
21
22. Summary
• Laryngeal assessment is needed before thyroidectomy
• IONM can help surgeon easily to identification and preservation of
nerve, especially in re-operation case, substernal goiter, cancer and
vocal fold dysfunction case.
22
The suspensory ligament of the thyroid gland, or Berry's ligament, is a suspensory ligament that passes from the thyroid gland to the trachea. Both the trachea and the thyroid are surrounded by a thin layer of fascia, which is separate from the thyroid capsule.