A thyroidectomy is an operation that involves the surgical removal of all or part of the thyroid gland. Surgeons often perform a thyroidectomy when a patient has thyroid cancer or some other condition of the thyroid gland (such as hyperthyroidism) or goiter. Other indications for surgery include cosmetic (very enlarged thyroid), or symptomatic obstruction (causing difficulties in swallowing or breathing). Thyroidectomy is a common surgical procedure that has several potential complications or sequela including: temporary or permanent change in voice, temporary or permanently low calcium, need for lifelong thyroid hormone replacement, bleeding, infection, and the remote possibility of airway obstruction due to bilateral vocal cord paralysis. Complications are uncommon when the procedure is performed by an experienced surgeon.
Less extreme variants of thyroidectomy include:
- "hemithyroidectomy" (or "unilateral lobectomy") -- removing only half of the thyroid
- "isthmectomy" -- removing the band of tissue (or isthmus) connecting the two lobes of the thyroid
A "thyroidectomy" should not be confused with a "thyroidotomy" ("thyrotomy"), which is a cutting into (-otomy) the thyroid, not a removal (-ectomy) of it. A thyroidotomy can be performed to get access for a median laryngotomy, or to perform a biopsy. (Although technically a biopsy involves removing some tissue, it is more frequently categorized as an -otomy than an -ectomy because the volume of tissue removed is minuscule.)
- Thyroid cancer
- Toxic thyroid nodule (produces too much thyroid hormone)
- Multinodular goiter (enlarged thyroid gland with many nodules), especially if there is compression of nearby structures
- Graves' disease, especially if there is exophthalmos (bulging eyes)
- Thyroid nodule, if fine needle aspirate (FNA) results are unclear
Types of Thyroidectomy 
- Hemithyroidectomy - Entire isthmus is removed along with 1 lobe. Done in benign diseases of only 1 lobe.
- Subtotal thyroidectomy - Done in toxic thyroid, primary or secondary, and also for toxic multinodular goiter (MNG).
- Partial thyroidectomy - Removal of gland in front of trachea after mobilization. Done in nontoxic MNG. Its role is controversial.
- Near total thyroidectomy - Both lobes are removed except for a small amount of thyroid tissue (on one or both sides) in the vicinity of the recurrent laryngeal nerve entry point and the superior parathyroid gland. Done in papillary thyroid carcinoma.
- Total thyroidectomy - Entire gland is removed. Done in case of follicular carcinoma of thyroid, medullary carcinoma of thyroid.
- Hartley Dunhill operation - Removal of 1 entire lateral lobe with isthmus and partial/subtotal removal of opposite lateral lobe. Done in nontoxic MNG.
Main steps of Thyroidectomy:
- Horizontal anterior neck incision (if possible, within a skin crease)
- Create upper and lower flaps between the platysma and strap muscles
- Divide vertically between the strap muscles and anterior jugular veins
- Separate the strap muscles from the thyroid gland
- Divide the middle thyroid vein
- Mobilize the superior pole of the thyroid lobe. Divide the superior thyroid artery and vein close to the thyroid gland (avoid injury to the external branch of the superior laryngeal nerve and the superior parathyroid gland)
- Identify the recurrent laryngeal nerve whenever possible using the nerve monitoring device
- Identify the inferior parathyroid artery
- Divide the inferior thyroid artery and vein
- Separate the thyroid lobe and isthmus from the trachea
- Repeat this process for the other thyroid lobe. Remove the thyroid gland
- Reapproximate the strap muscles
- Reapproximate the platysma muscle
- Close the skin with a subcuticular stitch
- Hypothyroidism/Thyroid insufficiency in up to 50% of patients after ten years
- Laryngeal nerve injury in about 1% of patients, in particular the recurrent laryngeal nerve: Unilateral damage results in a hoarse voice. Bilateral damage presents as laryngeal obstruction after surgery and can be a surgical emergency: an emergency tracheostomy may be needed. Recurrent Laryngeal nerve injury may occur during the ligature of the inferior thyroid artery.
- Hypoparathyroidism temporary (transient) in many patients, but permanent in about 1-4% of patients
- Anesthetic complications
- Stitch granuloma
- Chyle leak
- Haemorrhage/Hematoma (This may compress the airway, becoming life-threatening.)
- Surgical scar/keloid
- Removal or devascularization of the parathyroids.
- Thyroid storm in operations performed for hyperthyroidism
- Mathur AK and GM Doherty (2010). "Ch. 1: Thyroidectomy and Neck Dissection". In Minter RM and GM Doherty. Current Procedures: Surgery. New York: McGraw-Hill.
- Patient brochure from the American Thyroid Association
- Surgical procedures Comprehensible and elaborate information from the New York Thyroid Center
- Article at Endocrineweb, written by an MD Goes into more detail
- Early postoperative scar images
- Thyroid Surgery Tutorial From the Patient Education Institute
- Minimally invasive and daycase thyroid surgery Comprehensive information from a UK Specialist Surgeon