Background: Despite improved preoperative diagnostics, incidental postoperative detection of differentiated thyroid cancer in the final histology is still common. In most of these cases, completion thyroidectomy is recommended by national and international guidelines, although secondary surgery is associated with an increased operative risk. The optimal timing of completion thyroidectomy is still controversial.
Methods: Between January 1993 and December 2009, a total of 128 patients underwent completion thyroidectomy for differentiated thyroid carcinoma: papillary (n = 87) and follicular (n = 41). These patients were divided into five groups according to the time of the completion thyroidectomy after primary surgery (groups A, 1-3 days; B, 4-7 days; C, 1-7 weeks; D, 7-12 weeks; E, >3 months). Clinical complications and oncologic outcomes were analyzed. The mean follow-up was 82.5 ± 17 months.
Results: The overall rates of transient and persistent postoperative hypocalcemia were 7.0 and 3.1%, respectively. The rates of persistent hypocalcemia were significantly increased in groups B, C, and D in comparison to those in groups A and E (p < 0.003). The hypocalcemia rates were 7.1, 4.5, and 3.8% versus 0%, respectively. Transient or persistent vocal cord paresis was observed in eight (6.2%) and four patients (3.1%), respectively. The incidence of persistent vocal cord paresis (VCP) was significantly higher in groups B, C, and D than in groups A and E (p < 0.003). The VCP rates were 7.1, 4.5, and 3.8% versus 0%, respectively. There was no significant difference regarding survival or recurrence among the five groups.
Conclusions: Considering perioperative morbidity and oncologic outcomes, completion thyroidectomy should be performed either within 3 days or beyond 3 months after primary surgery.