What are the indications for thyroid artery embolization (TAE)?

Indications for Thyroid Artery Embolization

Thyroid artery embolization (TAE) should only be considered in exceptional circumstances when standard treatments (antithyroid drugs, radioactive iodine, or surgery) have failed or are contraindicated, and only at specialized centers with extensive embolization expertise. 1

Primary Indications

Graves' Disease and Thyrotoxicosis

• TAE is indicated for patients with Graves' disease who cannot tolerate or refuse standard therapies (antithyroid medications, radioactive iodine, or surgery). 2
• Specific scenarios include:
  • Methimazole-induced neutropenia preventing surgery 3
  • Thyroid storm in patients unable to undergo thyroidectomy 3
  • Severe cardiac contraindications to surgery (e.g., left ventricular insufficiency) 4
  • Patient refusal of both surgery and radioactive iodine therapy 2, 4
• Success rates show 63.6% of patients achieve euthyroid state without maintenance therapy, while others require reduced antithyroid drug doses 2

Large Cervicomediastinal Goiters

• TAE serves as preoperative preparation or palliative treatment for voluminous goiters, particularly those causing mediastinal compressive symptoms. 4
• Indications include:
  • Failed radioiodine metabolic therapy with persistent compressive symptoms 4
  • High surgical risk patients with large toxic goiters (thyroid volume >250 mL) 5
  • Hyperfunctioning goiters with mediastinal extension 4

Preoperative Adjunct for Toxic Goiter

• TAE may be used for rapid preoperative preparation in selected patients with toxic goiter who have antithyroid drug intolerance or refuse radioactive iodine. 5
• The procedure should be performed 24-36 hours before thyroidectomy 5
• While it reduces blood loss and operating time, the differences are modest and do not justify routine use 5

Thyroid Malignancy (Limited Role)

• TAE can facilitate safer surgery and alleviate symptoms in thyroid cancer patients, though evidence is extremely limited. 1
• This indication parallels the established use of preoperative embolization for highly vascularized metastases from kidney, melanoma, and thyroid cancer to reduce intraoperative bleeding. 6

Critical Contraindications and Cautions

Absolute Limitations

• TAE should NOT be considered routine treatment given the lack of standardized protocols, significant risk of serious complications (including nontarget embolization and mortality), and superior efficacy of established therapies. 1
• Current established therapies (antithyroid drugs, radioactive iodine, surgery) have higher efficacy and lower complication rates 1

Technical Requirements

• The procedure requires selective arteriography using Seldinger's technique 2
• Embolization targets superior and/or inferior thyroid arteries, and occasionally the thyroid ima artery when significantly enlarged 3
• Complete arterial occlusion must be confirmed with post-embolization angiography 5
• Particle size selection is critical: capillary diameter ranges 0.04-0.25 mm, while superior/inferior arteries measure 2-5.5 mm 2

Expected Outcomes and Complications

Benefits

• Thyroid volume reduction by one-third to one-half original size 2
• Resolution of compressive symptoms 4
• Normalization of thyroid function in hyperthyroid patients 4
• Reduced intraoperative blood loss when used preoperatively 5

Common Complications

• Neck pain and hematoma (minor, self-limiting) 1
• Arterial recanalization requiring repeat embolization 4

Serious Risks

• Nontarget embolization 1
• Mortality (rare but documented) 1
• Chemical inflammation, necrosis, and fibrosis of thyroid tissue 2

Clinical Pitfall to Avoid

Do not offer TAE as a first-line or routine alternative to established therapies. The absence of robust comparative data, standardized protocols, and the documented risk of serious complications including death mandate that TAE remain a last-resort option reserved for patients who have exhausted or cannot access standard treatments. 1 The procedure should only be performed at specialized centers with extensive embolization experience and immediate surgical backup capability. 1