Expert consensus statement on parathyroid protection in thyroidectomy

Thyroid cancer is the solid cancer with the most rapidly increasing incidence rate around the world. In 2012, the incidence rate of this condition has been the highest among malignancies in Korean women, ranking fourth in China. The most common pathological type is papillary thyroid carcinoma, accounting for about 80-85% of all thyroid cancers. Lymph node metastases are common in early papillary thyroid carcinoma, with a reported cervical metastasis rate of about 21-90%. Most investigators believe that the central zone is the first site of lymph node metastases, namely the sentinel lymph node. At present, surgery is the preferred treatment for thyroid cancer. Among others, total thyroidectomy with central lymph node dissection has become the most common surgical approach. The main complications are recurrent laryngeal nerve and parathyroid injury. The clinical application of neural monitors has played a positive role in intraoperative positioning and protection of the recurrent laryngeal nerve. Postoperative hypoparathyroidism due to parathyroid injury is still a challenge to thyroid surgeons. Parathyroid injuries include bruising, insufficient blood supply and mistaken incision. It is reported that the incidence rates of temporary and permanent hypoparathyroidism are 14-60% and 4-11% after thyroidectomy, respectively. A study showed that the incidence rates of transient and permanent hypoparathyroidism were 27.7% and 6.3% after total thyroidectomy, 36.1% and 7.0% after total resection with unilateral central lymph node dissection, and 51.9% and 16.2% after total thyroidectomy with bilateral central lymph node dissection, respectively. Temporary hypoparathyroidism may cause transient hypocalcemia symptoms, but will not have a large impact on the quality of life of patients. On the other hand, permanent hypoparathyroidism will cause permanent hypocalcemia symptoms, mostly limb numbness and spasms, seriously affecting the quality of life of patients, which is a main factor of medical disputes. Therefore, we should pay attention to the protection of the parathyroid gland during thyroid surgery.