To guide clinicians with evidence-based recommendations on the optimal surgical management of thyroid disease in adults, the American Association of Endocrine Surgeons has published the first comprehensive guidelines for safe, effective, and appropriate thyroidectomy in the Annals of Surgery.
Advances in the diagnosis and management of benign and malignant thyroid disease, including new cytologic and pathologic diagnostic criteria, molecular profiling tests, and operative techniques, have led the American Association of Endocrine Surgeons to formulate evidence-based guidelines on the epidemiology, pathogenesis, and diagnosis of thyroid disease; indications for surgical intervention; and associated perioperative management.
Evaluation and Indications for Surgery
The initial evaluation of thyroid disease should include personal and family history with emphasis on symptoms and radiation exposure, physical examination that includes voice assessment, and measurement of thyroid-stimulating hormone along with additional laboratory tests. Diagnostic ultrasound is strongly recommended in all patients with a suspected thyroid nodule, whereas computed tomography or magnetic resonance imaging with intravenous contrast is reserved for preoperative assessment in patients with suspected locoregional thyroid cancer.
Fine needle aspiration (FNA) biopsy is recommended for evaluation of suspicious thyroid nodules and lymph nodes, and ultrasound-guided FNA biopsy yield is better. Risk for malignancy in a thyroid nodule should be reported based on the Bethesda System for Reporting Thyroid Cytopathology.
Molecular testing can be used to refine the assessment of thyroid cancer risk and is reserved for cases when the need for thyroidectomy is unclear with the available clinical, imaging, and cytologic findings.
Thyroidectomy can be used for treatment of hyperthyroidism, and it is also strongly recommended to consider thyroidectomy for patients with compressive symptoms related to or progressive enlargement of a thyroid nodule, goiter, or thyroiditis. Diagnostic thyroidectomy is also acceptable for nodules that are cytologically categorized as Bethesda III or IV, and surgical intervention is indicated for thyroid nodules >1 cm categorized as Bethesda V or VI.
Preoperative Care
While there is no need for antimicrobial prophylaxis before surgery, a single dose of dexamethasone may reduce nausea, vomiting, and pain. A potassium iodide-containing preparation can be considered before surgery for Graves disease, as well as calcium and vitamin D supplements. Patients who have undergone bariatric surgery should be counseled about and monitored for severe hypocalcemia after thyroidectomy. Laryngeal examination should be performed in patients with vocal abnormalities, preexisting laryngeal disorders, previous at-risk surgery, or locally advanced thyroid cancer. The possibility and likelihood of vocal fold dysfunction should also be discussed with the patient.
Surgical Approach
The guidelines provide several recommendations on surgical approach to reduce the risk for complications, including ligating the superior pole vessels close to the thyroid capsule, identifying the recurrent laryngeal nerve (RLN), dissection along the thyroid capsule, and parathyroid autoimplantation when a parathyroid gland cannot be preserved. There is no clear evidence for the benefits of RLN monitoring in preventing RLN injury, but it may assist during surgery and may lead the surgeon to consider stopping the operation if it suggests loss of function.
Intraoperative pathologic evaluation, usually performed by frozen section analysis and/or cytologic touch or scrape analysis, should only be performed when the information is likely to alter operative procedures and can assist in identifying parathyroid tissue and lymph node metastases.
The central compartment should be assessed for suspicious lymphadenopathy in all cases of papillary thyroid cancer, and a therapeutic central compartment neck dissection is strongly recommended when there is clinical or radiologic evidence for macroscopic disease. A compartment-oriented therapeutic lateral neck dissection is recommended for lateral lymph node metastasis.
Preoperative evaluation for hypercalcemia and hyperparathyroidism may be important, and in cases of primary hyperparathyroidism, it is strongly recommended to complete concurrent parathyroidectomy with the initial thyroid surgery.
The recommended surgical approach for nontoxic goiter is dependent on the clinical symptoms and the extent of involvement, as total thyroidectomy is preferred for bilateral goiter and lobectomy and isthmusectomy are recommended for unilateral goiter.
Familial Thyroid Cancer
The guidelines also provide recommendations on familial thyroid cancer, including a strong recommendation to complete screening for differentiated thyroid cancer in individuals from families with ≥3 affected first-degree relatives. All patients diagnosed with medullary thyroid carcinoma should undergo genetic testing for a germline RET mutation, and those with multiple endocrine neoplasia should be managed by an experienced multidisciplinary team.
Cancer Management and Reoperation
When patients who underwent lobectomy or isthmusectomy are diagnosed with a high-risk thyroid cancer and/or when there is an indication for radioactive iodine, it is strongly recommended to consider completion thyroidectomy. In cases of prophylactic thyroidectomy for medullary thyroid carcinoma, total thyroidectomy is the recommended surgery. An active surveillance protocol may be appropriate for selected patients with small papillary thyroid carcinomas and can be suitable for selected individuals with stable, low-volume persistent or recurrent lymph node metastases.
The experts involved in the guideline writing process hope that these guidelines will assist clinicians in providing the optimal surgical management of benign and malignant thyroid disease.
Reference
Patel KN, Yip L, Lubitz CC, et al. The American Association of Endocrine Surgeons guidelines for the definitive surgical management of thyroid disease in adults. Ann Surg. 2020;271(3):e21-e93.