Anthropometric Measures, Recurrent Laryngeal Nerves Diameter, Electromyographic Responses and Vocal Cord Paralysis...

Area of Science:

• Neurosurgery
• Anatomy
• Electrophysiology

Background:

• Recurrent laryngeal nerve (RLN) injury is a risk during thyroid and neck surgeries.
• Intraoperative nerve monitoring (IONM) is crucial for preventing RLN damage.
• Understanding factors influencing RLN diameter and injury risk is important for surgical safety.

Purpose of the Study:

• To investigate the association between anthropometric measurements and RLN diameter.
• To compare baseline electromyographic (EMG) characteristics of thin versus thick RLNs.
• To assess if thin or branched RLN morphology increases the risk of EMG adverse events, loss of signal (LOS), or vocal cord paresis/paralysis (VCP).

Main Methods:

• Prospective study collecting anthropometric data (weight, height, BMI, neck circumference, shoulder diameter, finger circumference).
• RLN diameter measured, with thin nerves defined as ≤1.5 mm.
• Baseline EMG characteristics and adverse events (LOS, VCP) recorded during IONM.

Main Results:

• Multiple anthropometric factors (e.g., female sex, lower BMI, height, neck circumference) were associated with smaller RLN diameters (p < 0.05).
• No significant differences in baseline EMG characteristics were found between thin and thick RLNs, except for R2 latency in the right RLN.
• Zero cases of LOS or VCP were observed, and motor fibers in branched nerves were located in the anterior branch.

Conclusions:

• Anthropometric measurements are linked to RLN diameter.
• RLN diameter did not significantly impact most baseline EMG characteristics.
• The study, with zero adverse events, lacks power to confirm thin or branched morphology as independent risk factors for RLN injury in high-volume endocrine surgery with IONM.