- Clinical science
Thyroid surgery is a procedure commonly performed to treat benign and malignant thyroid disorders. Total thyroidectomy entails the removal of the entire thyroid gland and is indicated in the management of thyroid cancer or benign thyroid conditions that affect the entire gland (e.g., Graves' disease, multinodular goiter). A small cuff of tissue adjacent to the tracheoesophageal groove is spared in near total and subtotal thyroidectomy in order to protect the parathyroid glands and the adjacent nerves. Lobectomy (removal of a single lobe) or hemithyroidectomy (removal of a single lobe with the isthmus) is performed for unilateral benign thyroid disorders (e.g., toxic adenoma, recurrent thyroid cysts) and for small, low-risk differentiated thyroid cancers. Postoperative complications include hematoma formation, hypoparathyroidism, nerve palsy (recurrent/superior laryngeal nerve), and hypothyroidism. The greater the extent of resection, the greater the risk of complications. However, the most extensive resections (total thyroidectomy) are associated with the lowest rates of recurrent disease.
- A shield-shaped gland located anteriorly in the lower part of the neck
- Has 2 lobes connected by an isthmus; an ascending pyramidal lobe may be present in 50% of the population
- Extends from C5 to T1
- Encapsulated by the pretracheal fascia (false/surgical capsule)
- Arterial supply: superior and inferior thyroid arteries
- Venous drainage: the superior, middle, and inferior thyroid veins
- Relations of the thyroid gland
- Nerves in close proximity to the thyroid gland
- Achieve euthyroid status preoperatively.
- Preoperative oral calcium and vitamin D supplementation: to minimize postoperative hypocalcemia (esp. after total thyroidectomy)
- Preoperative direct/indirect laryngoscopy: to assess vocal cord mobility/dysfunction
Steps of thyroid surgery
- Position (Kocher's position): supine with a pad placed under the shoulders to enable neck extension and adequately expose the thyroid gland
- Kocher's incision: a skin crease incision ∼ 2–3 cm above the clavicular heads; as deep as the subplatysmal plane
- Raising the skin flaps (subplatysmal plane) to the thyroid cartilage superiorly and the suprasternal notch inferiorly
- Separation of the strap muscles: The deep fascia is incised longitudinally in the midline and the strap muscles are retracted laterally to expose the thyroid gland.
- Ligation of the middle thyroid vein
- Ligation of the superior thyroid artery and vein; identification and preservation of the superior laryngeal nerve
- Identification and preservation of the recurrent laryngeal nerve
- Ligation of the inferior thyroid vein and thyroid branches of the inferior thyroid artery
- Identification and preservation of the parathyroid glands
- Autotransplantation of parathyroid glands into the sternocleidomastoid muscle is indicated if the glands appear ischemic or if they have been mistakenly excised during thyroidectomy (to avoid permanent hypoparathyroidism). Depending on the extent of resection (see below), the procedure can be repeated on the other side (for total/near total/subtotal thyroidectomy).
- Closure: Hemostasis is achieved, the wound bed is irrigated, the strap muscles are sutured in the midline, and the skin flaps are sutured together.
Near total thyroidectomy
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|Subtotal thyroidectomy|| |
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- Minimally invasive/robotic thyroidectomy: Endoscopic/robotic instruments are tunneled into the neck to perform thyroidectomy; small incisions are made in the axilla/chest wall. The advantage is that no scars are left on the neck.
- Transient/permanent postoperative (most common) or hypothyroidism
- Transient/permanent RLN palsy
- Superior laryngeal nerve palsy → paralysis of cricothyroid muscle → easy voice fatigability; change in the timbre of voice
- : if the surgery was performed in inadequately treated patients with hyperthyroidism (see "complications" of for further details)
- Rare complications: injury to the trachea or the esophagus;
|Unilateral RLN palsy||Bilateral RLN palsy|
We list the most important complications. The selection is not exhaustive.