The clinical presentation and operative management of nodular and diffuse substernal thyroid disease

Patients with substernal thyroid disease, defined by the presence of enlarged thyroid tissue below the plane of the thoracic inlet, were identified from a prospective database maintained for patients who have undergone thyroidectomy at our institution since 1990. Substernal thyroid disease was present in 116 (30%) of 381 patients, anterior mediastinal in 109 (94%), and posterior mediastinal in seven (6%). Indications for surgery included compressive symptoms in 75 (65%) patients, an abnormal fine-needle biopsy in 45 (39%), progressive thyroid enlargement in 41 (35%), thyrotoxicosis in 11 (10%), and superior vena cava syndrome in two (1.7%). A median sternotomy and thoracotomy were performed in one patient each for a primary intrathoracic goiter. In all other patients thyroidectomy was accomplished through a cervical incision. Parathyroid autotransplantation was performed in 41 (37%) patients with retrosternal disease compared with 57 (22%) with disease confined to the neck (P < 0.01). Twenty-five patients (22%) had malignancy; four of these had unresectable disease. Postoperative complications included transient hypocalcemia (n = 46), transient hoarseness (n = 7), recurrent laryngeal nerve injury (n = 1), and wound infection (n = 1). One patient died from aspiration pneumonia. In summary, substernal thyroid disease is typically present in the anterior mediastinum and with rare exceptions can be resected through a cervical incision. Parathyroid devascularization is more common with resection of a substernal goiter and autotransplantation can prevent permanent hypoparathyroidism.