Steps in Thyroidectomy

Indications (when it is done)

• Thyroid cancer or suspicious nodule
• Goiter with compressive symptoms
• Hyperthyroidism refractory to medical management (Graves disease, toxic nodule)

Preoperative Preparation

• Thyroid function tests (TSH, free T4)
• Neck ultrasound; FNA biopsy of suspicious nodules
• Serum calcium if MEN2A or concurrent hyperparathyroidism is suspected
• For hyperthyroidism: achieve euthyroid state preoperatively with antithyroid drugs (propylthiouracil/methimazole) +/- beta-blockade; Lugol's iodine solution may be added within 10 days before surgery to reduce gland vascularity

• Preoperative voice history is mandatory for all patients
• Laryngoscopy or transcutaneous laryngeal ultrasound for higher-risk patients (prior neck surgery, voice changes, posterior extrathyroidal extension)

Anesthesia and Positioning

• General endotracheal anesthesia (most cases)
• If intraoperative nerve monitoring (IONM) is used, a neuromonitoring ETT with surface electrodes is placed in contact with the vocal cords; muscle relaxation is contraindicated with IONM
• Patient supine, both arms tucked, back raised ~20 degrees
• Neck extended by placing a soft roll behind the scapulae, with the head on a foam/gel ring - this brings the thyroid anteriorly, especially helpful for substernal glands
• Preincision intraoperative neck ultrasound may be done to confirm anatomy

Step 1 - Incision and Creating Subplatysmal Flaps

• A transverse (Kocher) incision is made centrally, between the sternal notch and the cricoid cartilage, placed in a natural skin crease for cosmesis
• Length typically 4-5 cm, adjusted for gland size and body habitus
• Incision through skin and platysma muscle
• Subplatysmal flaps raised: superiorly up to the thyroid cartilage, inferiorly to the sternal notch
• Anterior jugular veins are identified between the platysma and strap muscles

Step 2 - Division of Strap Muscles and Thyroid Exposure

• Strap muscles separated in the midline avascular plane (through the superficial layer of the deep cervical fascia) from the sternal notch to the thyroid cartilage
• The sternohyoid (superficial) is separated from the deeper sternothyroid by blunt dissection; dissection can extend laterally until the ansa cervicalis is visible at the lateral border of the sternothyroid
• Sternothyroid is dissected off the thyroid capsule
• Thyroid lobe is retracted anteromedially, exposing the carotid sheath laterally
• For large goiters, the sternothyroid may be partially or completely divided near its superior attachment and reapproximated at closure
• The middle thyroid vein is identified laterally, then ligated and divided

Step 3 - Dissection and Release of the Superior Pole

• Superior pole attachments separated from surrounding muscles by blunt dissection (peanut sponge); thyroid retracted downward and laterally
• Medial separation of the superior pole from the cricothyroid muscle uses the avascular space of Reeves
• Superior pole vessels (branches of the superior thyroid artery) are individually isolated, ligated, and divided close to the thyroid surface - this protects the external branch of the superior laryngeal nerve (EBSLN), which runs along the cricothyroid muscle just medial to these vessels
• IONM can help identify and preserve the EBSLN
• After dividing the superior pole vessels, remaining filmy posterior tissues are swept away by blunt dissection
• At this point the superior parathyroid gland is often identified behind the mid-superior pole at the level of the cricoid cartilage

Step 4 - Mobilization of the Inferior Pole and Medial Rotation

• The inferior thyroid lobe is grasped with an Allis clamp and retracted superomedially
• Loose areolar tissue along the inferior and lateral aspects is divided
• The inferior parathyroid gland is identified (usually anterior/inferior to the inferior thyroid artery, near the inferior pole)
• Both parathyroid glands must be identified and their blood supply preserved on the posterior capsule of the thyroid by careful dissection

Step 5 - Identification and Preservation of the Recurrent Laryngeal Nerve (RLN)

• The RLN is identified in the tracheoesophageal groove on the medial side of the posterolateral thyroid, typically at the level of the inferior thyroid artery
• The nerve is traced from a safe inferior location superiorly to its entry into the larynx through the ligament of Berry at the level of the cricoid cartilage
• The RLN passes through the ligament of Berry and dives deep to the laryngeal insertion point - extra care is taken here as branches of the nerve may divide near this point
• IONM (vagal stimulation or direct nerve stimulation) is used to confirm nerve identity and functional integrity
• Parathyroid glands are carefully dissected off the thyroid capsule with their vascular pedicle intact; devascularized glands are minced and autotransplanted into the sternocleidomastoid muscle

Step 6 - Division of the Ligament of Berry and Lobe Removal

• With the RLN clearly identified, the ligament of Berry (a dense fibrous condensation between the posteromedial thyroid and the trachea) is carefully divided
• The thyroid lobe is freed from the trachea by dividing remaining fibrous attachments
• For total thyroidectomy: the above steps are repeated on the contralateral side

Step 7 - Division of the Isthmus (and Pyramidal Lobe)

• The thyroid isthmus is divided between clamps or with an energy device
• The pyramidal lobe, if present, is traced superiorly toward the hyoid and divided
• This completes the specimen

Step 8 - Hemostasis, Inspection, and Closure

• Meticulous hemostasis of the thyroid bed
• The specimen is inspected for inadvertently excised parathyroid tissue (confirmed by frozen section or intraoperative PTH aspiration); any such tissue is minced and autotransplanted into the sternocleidomastoid
• Drain placement is optional and surgeon-dependent
• Strap muscles are reapproximated in the midline
• Platysma closed with absorbable suture
• Skin closed with subcuticular suture or skin staples

Postoperative Care

• Thyroid hormone replacement commenced before discharge for total thyroidectomy (hypothyroidism expected at 2-4 weeks)
• Serum calcium monitored postoperatively; prophylactic calcium +/- calcitriol in high-risk patients
• Laryngoscopy for any postoperative voice changes

Key Structures at Risk (and Complications)