What are the basic steps in hemithyroidectomy (partial thyroid removal) surgery?

Basic Steps in Hemithyroidectomy Surgery

Hemithyroidectomy is a surgical procedure that involves the removal of one lobe of the thyroid gland along with the isthmus, and can be safely performed with proper technique and attention to critical anatomical structures. The procedure requires meticulous dissection and identification of vital structures to minimize complications, particularly those affecting voice outcomes.

Preoperative Preparation

• Preoperative assessment:

  • Document baseline voice assessment 1
  • Examine vocal fold mobility if voice is impaired or if patient has risk factors (thyroid cancer with extrathyroidal extension, prior neck surgery) 1
  • Communicate any abnormal laryngeal findings to the anesthesiologist 1

• Anesthesia considerations:

  • Endotracheal intubation is usually required (laryngeal mask airway is sometimes used) 1
  • If nerve monitoring will be used, avoid long-acting paralytic agents 1
  • Ensure proper endotracheal tube placement if nerve monitoring is planned 1

Surgical Technique

1. Patient Positioning and Incision

• Position patient with neck extended using shoulder roll
• Mark incision in a natural skin crease, typically 2-3 cm above the sternal notch
• Make a symmetric incision of appropriate length (typically 4-6 cm)

2. Flap Creation

• Elevate subplatysmal flaps superiorly to the thyroid cartilage and inferiorly to the sternal notch
• Divide the median raphe between strap muscles
• Retract strap muscles laterally to expose the thyroid gland

3. Thyroid Mobilization

• Ligate and divide the middle thyroid vein
• Identify and preserve the recurrent laryngeal nerve (RLN) 1
• Identify and preserve the external branch of the superior laryngeal nerve (EBSLN) 1
• Mobilize the superior pole with careful ligation of superior thyroid vessels
• Dissect and mobilize the inferior pole with preservation of parathyroid glands

4. Isthmus Division

• Clamp, divide, and ligate the thyroid isthmus
• Separate the thyroid lobe from the trachea

5. Final Dissection and Removal

• Complete the dissection posteriorly with careful attention to the RLN
• Remove the thyroid lobe and isthmus
• Achieve meticulous hemostasis

6. Closure

• Irrigate the wound
• Close the strap muscles in the midline
• Close subcutaneous tissue and skin
• Apply a light dressing

Critical Steps for Voice Preservation

1. Recurrent laryngeal nerve identification: The RLN must be identified and preserved during surgery to prevent voice impairment 1

2. Superior laryngeal nerve preservation: Take steps to preserve the external branch of the superior laryngeal nerve to maintain voice pitch 1

3. Careful dissection: Perform meticulous dissection around nerves to avoid traction or thermal injury

Postoperative Management

• Monitor for potential complications:

  • Hematoma formation (requires immediate attention if occurs) 1
  • Voice changes (document any changes) 1
  • Hypocalcemia (less common with hemithyroidectomy than total thyroidectomy) 2

• Emergency preparedness:

  • A post-thyroid surgery emergency box should be available at the bedside 1
  • Emergency front-of-neck airway equipment must be readily available 1
  • If hematoma with airway compromise occurs, follow the SCOOP approach (Skin exposure; Cut sutures; Open skin; Open muscles; Pack wound) 1

Complications to Monitor

• Voice changes: Examine vocal fold mobility if voice changes persist 2 weeks after surgery 1
• Bleeding: Risk factors include larger thyroid size 3
• Recurrent laryngeal nerve injury: Permanent RLN paresis is less common in diagnostic hemithyroidectomies compared to those performed for compression symptoms 3
• Hypothyroidism: More common in older patients and those with thyroiditis 4

Follow-up Considerations

• Assess thyroid function 4-6 weeks postoperatively
• Approximately 9.5% of patients require thyroid hormone replacement therapy after hemithyroidectomy 4
• Risk factors for postoperative hypothyroidism include increased age and presence of thyroiditis 4

Hemithyroidectomy is generally a safe procedure with low complication rates when performed by experienced surgeons. Careful attention to nerve identification and preservation is critical for maintaining voice quality and reducing morbidity.