Anatomical approach to surgery for intrathoracic goiter.

The anatomical approach to the intrathoracic goiter (ITG) was used to understand its etiology and to rationalize surgical technique of thyroidectomy. For a retrospective chart review, we selected cases of multinodular goiter with totally ITGs (n = 69; M 29, F 40), while 916 cases with cervical goiter were used for comparison. The topography of the thyroid gland was assessed against the tracheal rings and against the vertebrae. The regional anatomy of the thoracic inlet was assessed by its bony margins and the relations of structures traversing the area. Average tracheal-diameter-to-thoracic-inlet ratio was calculated. The ITG group consisted of 52 cases of retrosternal goiter (75.4 %), nine cases of retrotracheal goiter (13 %), and eight cases of retroesophageal goiter (11.6 %). In all but one analyzed cases, the goiters were removed via cervical incision. Mean weight of goiters was 183 g. The area of thoracic inlet in the cases of ITG had no difference in comparison with the cases of cervical goiter (F/M p = 0.11/0.15), but the tracheal-diameter-to-thoracic-inlet ratio was significantly smaller (F/M p = 0.06/0.04). In the ITG cases, the position of the upper edge of the isthmus of the thyroid was about 1.5 tracheal rings lower than in healthy individuals (p = 0.03). The area of the thoracic inlet, the neck size, and the anteroposterior diameter of the inlet do not affect the development of the ITG. The smaller tracheal-diameter-to-thoracic-inlet ratio and the lower position of the thyroid gland are the main indicators for the development of the ITG.