Surgical anatomy in minimally invasive thyroidectomy

Abstract

Thyroid gland is a butterfly-shaped organ that lies over the anterior trachea wrapping around the upper tracheal rings just deep to the sternothyroid and sternohyoid muscles. The superior and inferior arteries are derived as pairs from the external carotid arteries and the thyrocervical trunks, respectively. The veins are more variable than the arterial supply and may reach enormous sizes in enlarged glands. The thyroid gland is richly endowed with lymphatics, and the flow may drain in many directions from the gland. Two nerves require special attention during thyroidectomy: the recurrent laryngeal nerve (RLN) and the external branch of the superior laryngeal nerve (EBSLN). Bilateral RLN injuries have dramatic clinical presentation either with a complete loss of voice or with complete airway obstruction. Injury to the EBSLN is manifested with mild hoarseness, voice weakness or fatigue, loss of voice range, and lower voice volume. Parathyroid glands are in close relation with the recurrent laryngeal nerve.