The feasibility and efficacy of secondary neck dissections in thyroid cancer metastases

The purpose of the study was to assess the feasibility of secondary neck dissections (ND) in different types of thyroid cancer (TC), to evaluate the influence of ND extent on morbidity and to describe biochemical and clinical outcomes. 51 patients previously operated for TC (33-well differentiated TC-WDTC, 15 medullary TC-MTC, 3 poorly differentiated TC-PDTC) presenting detectable nodal disease. Reoperations covered I-VII neck levels. Radical neck dissection was performed in 22 patients, selective neck dissection in 29 patients. 14 central compartment (CC), 10 mediastinal and 41 level IV excisions were performed. Postoperative complications occurred in 13 patients: 4 chyle leaks, 3 massive bleedings, 8 permanent vocal cord pareses, hypoparathyroidism in 22 patients (43.1%), 2 patients expired in perioperative period. In WDTC: in seven patients thyroglobulin level normalized directly after ND, in ten patients in the follow-up; six patients developed distant metastases. None of the patients with MTC achieved calcitonin level <10 pg/ml; nine patients developed distant metastases. None of the patients with PDTC achieved Tg <2 mg/ml; two patients died, the third developed distant metastases. Secondary ND in TC present a challenge by means of surgical approach and possibility of complications. In MTC and PDTC the long-term results were unsatisfactory. In WDTC, the secondary ND should be performed due to strong indications. Metastases localization in levels IV, VI, VII were connected with high complication rate, but these surgeries were crucial for satisfactory oncological outcomes.