The role of thymus preservation in parathyroid gland function and surgical completeness after bilateral central lymph...

The clinical value of thymus preservation during thyroid carcinoma surgery remains unclear. The aim of this study is to explore the role of bilateral thymus preservation in parathyroid glands (PGs) function and surgical completeness in total thyroidectomy (TT) with bilateral central lymph node dissection (CLND).

Fifty-four consecutive patients who underwent TT and bilateral CLND were assigned to the thymus preservation (TP) group (n = 27) and the bilateral thymectomy (BT) group (n = 27). Surgical completeness was evaluated by the number of lymph nodes dissected, serum Tg level and ultrasound findings postoperatively.

Incidental parathyroidectomy was more common in the BT group (29.6% vs 7.4%, p = 0.038). Patients in the BT group had higher risks of neuromuscular symptoms (63.0% vs 29.6%, P = 0.014) and transient hypoparathyroidism (70.4% vs 25.9%, P = 0.001). The incidence of persistent hypoparathyroidism failed to show a significant difference between the TP and BT groups (0 vs 14.8%, P = 0.111). However, those with transient hypoparathyroidism in the BT group had a lower level of serum PTH at 3 weeks postoperatively (p = 0.001). There was no significant difference in the number of lymph nodes dissected (5.89 ± 3.12 vs 8.56 ± 6.93, P = 0.077) and preablation sTg level (1.82 ± 2.18 vs 1.42 ± 1.56 ng/ml, P = 0.775) between the TP and BT groups. No metastatic lymph nodes were found on sonography at 3 months postoperatively in both groups.

Thymus preservation had benefits on protecting PGs and promoting rapid clinical resolution of hypoparathyroidism. It had no effects on oncologic completeness of TT with bilateral CLND.