Thyroidectomy Guidelines

Introduction to Thyroidectomy Workup

• The American Academy of Otolaryngology-Head and Neck Surgery recommends a comprehensive pre-operative assessment of airway and vocal cord function in elderly patients undergoing thyroidectomy, including laryngeal examination to identify any abnormal vocal fold mobility, assessment of tracheal compression or deviation, and evaluation for potential difficult intubation due to goiter 1

Diagnostic Tests

• The Annals of Oncology suggests considering serum calcitonin if medullary thyroid cancer is suspected in patients with goiter 2
• The American Academy of Otolaryngology-Head and Neck Surgery recommends fine-needle aspiration biopsy for suspicious nodules to rule out malignancy, particularly important in elderly patients as the incidence of malignancy increases with age and tumors are usually more aggressive 1
• The American College of Radiology recommends TSH as the initial test for laboratory assessment, followed by free T4 or Free T4 Index measurement in suspected hypo/hyperthyroidism 3, 4
• Urinary iodine excretion (24-hour collection) is used to assess iodine status, as recommended by Clinical Nutrition 5
• Thyroid ultrasound is the first-line imaging study to evaluate morphology, according to the Journal of the American College of Radiology 4
• The American College of Radiology recommends starting with a thyroid ultrasound as the initial study, followed by thyroid function tests and fine-needle aspiration biopsy (FNAB) for suspicious nodules, to confirm the thyroid origin of the mass, characterize size, morphology, and evaluate suspicious characteristics of malignancy in nodules 4
• Scintigraphy is essential to confirm autonomous functioning nodules and differentiate from other causes of hyperthyroidism, such as Graves' disease 4
• CT or MRI of the neck is recommended when substernal extension, retropharyngeal extension, or tracheal compression is suspected, with CT preferred over MRI due to less respiratory motion artifact 4

Airway Evaluation and Anesthesia Planning

• The American Academy of Otolaryngology-Head and Neck Surgery recommends laryngeal examination to identify any abnormal vocal fold mobility, assessment of tracheal compression or deviation, and evaluation for potential difficult intubation due to goiter in elderly patients undergoing thyroidectomy 1
• The American Academy of Otolaryngology-Head and Neck Surgery suggests communicating with the anesthesia team early about potential airway challenges, including abnormal vocal fold mobility, ability to visualize the laryngeal inlet, altered laryngeal anatomy, and hypopharyngeal crowding or compression 1
• The American Academy of Otolaryngology-Head and Neck Surgery recommends communication between surgeon and anesthesiologist regarding abnormal vocal fold mobility, ability to visualize the laryngeal inlet, altered laryngeal anatomy, and hypopharyngeal crowding or compression in elderly patients undergoing thyroidectomy 1

Etiology and Risk Factors

• Iodine deficiency is a principal risk factor worldwide, along with female sex, age, exposure to goitrogens, hereditary factors, deficiency of selenium and iron, and smoking 4
• Hashimoto's thyroiditis is the most frequent cause of goiter in industrialized nations with adequate iodine intake, according to the American Academy of Family Physicians 3
• Graves' disease and congenital hypothyroidism can also cause goiter, as noted by the American Academy of Family Physicians 3
• DICER1 gene mutations are associated with an increased risk of MNG development, with a cumulative incidence of 13% in males and 32% in females by 20 years of age, according to the American College of Medical Genetics and Genomics 6
• Familial forms of MNG suggest a strong genetic predisposition, with certain genetic syndromes like DICER1-related tumor predisposition associated with a higher risk of thyroid cancer development, as reported by the National Cancer Institute 6, 7

Clinical Presentation

• Patients with thyroid goiter may be asymptomatic or present with a visible or palpable mass in the neck, sensation of cervical pressure, difficulty swallowing, difficulty breathing, hoarseness or changes in voice, or dry cough 4
• Children with goiter may present with visible or palpable neck mass, difficulty swallowing, difficulty breathing, voice changes, or symptoms of hypothyroidism or hyperthyroidism, and in severe cases, developmental delays or intellectual disability (cretinism) 3

Treatment and Management

• The American Academy of Family Physicians recommends iodine supplementation, particularly in the first and second trimesters, to prevent neurological abnormalities in cases of iodine deficiency 3
• Levothyroxine replacement therapy is used to treat hypothyroidism caused by autoimmune thyroiditis, as recommended by the American Academy of Family Physicians 3
• Thionamides, radioactive iodine, or surgery may be used to treat hyperthyroidism caused by autoimmune thyroiditis, according to the American Academy of Family Physicians 3
• Treatment options for toxic nodular goiter include medical therapy with antithyroid drugs like methimazole, definitive treatment with radioactive iodine, or surgery 4
• For asymptomatic goiter with benign cytology, periodic follow-up with ultrasound and thyroid function tests is recommended, and consideration of levothyroxine therapy to suppress TSH may be given, although its efficacy is limited in long-standing nodular goiter 4
• For goiter with compressive symptoms or suspicious/malignant nodules, thyroidectomy (total or subtotal depending on extension) is indicated, and for high-surgical-risk patients, radioactive iodine may be considered 2

Post-Treatment Care

• Post-thyroidectomy, hormone replacement therapy, calcium and vitamin D monitoring (for risk of hypoparathyroidism), and vocal rehabilitation if dysphonia is present are recommended 4
• Post-radioactive iodine treatment, monitoring of thyroid function to detect hypothyroidism and ultrasonographic follow-up to evaluate size reduction are recommended 4
• The American College of Radiology recommends post-treatment care for thyroid goiter, including hormone replacement therapy post-thyroidectomy, vocal rehabilitation in case of post-surgical dysphonia, calcium and vitamin D supplementation in post-surgical hypoparathyroidism, periodic follow-up with ultrasound and thyroid function tests, and psychological support for adaptation to changes in body image 4