Endovascular Embolization of Thyroid Arteries for Treatment of Thyroid Goiter

Introduction: Nodular thyroid goiter affects up to 6% of the population and prevalence is expected to increase with an aging population. FNA-negative, benign thyroid goiters can grow to large sizes and cause symptoms related to mass effect on adjacent mediastinal structures. Standard of care surgery can carry significant morbidity, particularly with lesions extending into the retro/substernal space. Radio-ablation frequently necessitates multiple treatments and can be technically limited by difficult-to-reach locations. Endovascular thyroid artery embolization represents a promising, minimally invasive alternative. We describe our early experience in a case series of 5 patients.

Methods: We reviewed the EMR of 5 patients with bilateral nodular thyroid goiter referred for neurosurgical endovascular embolization at NYU Langone Health in 2023. All patients underwent baseline thyroid function testing, neck ultrasound and/or CT neck with contrast. FNA biopsy confirmed benign cytology prior to treatment. Catheter angiography was performed through right femoral arterial access. Embolic material using 45-355 um polyvinyl alcohol (PVA) spheres or embospheres (tris-arcyl polymer) were infused in target vessels until satisfactory distal stagnation of contrast. Patients were monitored for 24 hours post-procedurally.

Results: Unilateral superior/inferior thyroid arteries were both embolized in 3 patients, and either the superior or inferior thyroid artery embolized in isolation in 2 patients. 4/5 patients had available imaging at follow-up between 1 – 4 months post-procedurally. All 4 patients demonstrated radiographic or sonographic regression of ipsilateral goiter (up to 25%) and improvement in symptoms including globus sensation and intermittent dyspnea/dysphagia. One patient demonstrated impressive size reduction of contralateral goiter secondary to intrathyroidal collateralization. One patient suffered from particle reflux into intracranial circulation with small ipsilateral watershed infarcts and made complete neurologic recovery by 4-month follow-up. Thyroid function was preserved with exception of transient hyperthyroidism (n=1) and mild thyroiditis (n=1) managed conservatively.

Conclusion : Thyroid artery embolization is an effective treatment strategy for large FNA-negative thyroid goiters and should be incorporated into the growing armamentarium of endovascular neurosurgeons. Longer term studies evaluating the kinetics of response and preservation of thyroid function are warranted.