RESUMO
INTRODUCTION AND IMPORTANCE: The majority of surgical thyroid disorders are treated by thyroidectomy (total or hemithyroidectomy). Anatomical variants of embryologic origin may threaten the effectiveness of thyroid surgery and complete removal of thyroid tissue. CASE PRESENTATION: A female patient who underwent a total thyroidectomy, postoperatively had normal serum thyroid-stimulating hormone (TSH) levels without hormone replacement. Serum TSH and thyroglobulin levels were within normal range. A thyroid nuclear scan and chest magnetic resonance imaging (MRI) indicated a large retrosternal thyroid remnant. Clinical discussion: Separated thyroid remnant in the thyrothymic tract, forgotten during primary surgery, was the source of hormone production. Total thyroidectomy was not achieved due to embryologic remnant, and complete resection of thyroid tissue was affected by separated retrosternal thyrothymic rest. CONCLUSION: Surgeon awareness of anatomic variants of embryological origin undoubtedly improves thyroid surgery outcomes. Beside the anatomically based approach, total thyroidectomy could be achieved by an embryologically based approach.
RESUMO
Thyroid reoperations are surgically challenging because of scarring and disturbances in the anatomy of the recurrent laryngeal nerve (RLN). This study was conducted on 49 patients who underwent redo surgery. 61 RLNs were identified and completely exposed. Their functional integrity was evaluated using intraoperative nerve monitoring (IONM). Indications for secondary surgery, anatomical changes secondary to recurrent goiter mass and prior surgery, and results of IONM were studied. Frequent indications for redo surgery were multinodular goiter (MNG) in 19 (38.8%) and results of cytology in 14 (28.5%) patients. The mean time interval between primary and redo thyroid surgery was 23.4 years. We laterally approached 41 (67.2%) thyroid lobes between the sternocleidomastoid and sternohyoid muscles. 16 (26.2%) RLNs were found to be adherent to the lateral surface of the corresponding thyroid lobe. The functional integrity of all RLNs was confirmed by IONM. The remnant thyroid tissue can then lead to goiter recurrence requiring secondary surgery after a long period of time. The indications for redo surgery were similar to primary cases. Lateral displacement of the RLN which is adherent to the lateral surface of recurrent goiter mass is common anatomic variation. Thyroid reoperations based on awareness of anatomical disturbances can be performed safely by an experienced surgeon with support of ancillary electrophysiological technology.