ABSTRACT
Objective:To observe the effect of different clinical factors on the level of parathyroid hormone (PTH) and to predict the possibility of permanent hypothyroidism (PHP) after total thyroidectomy (TT) by monitoring the levels of PTH in serum and drainage fluid after TT.Methods:Retrospective analysis was made on 150 patients who underwent TT for papillary thyroid carcinoma (PTC) in the Department of Thyroid Head and Neck Surgery in Jilin Cancer Hospital from Jan. 2020 to Aug. 2021. The changes of serum PTH were recorded at 1, 3, 7, 30 days and 6 months after surgery. The risk factors of postoperative hypoparathyroidism (HP) were investigated by single factor and multi factor methods. The impairment of parathyroid function was predicted combined with the level of PTH in the drainage fluid 1 day after operation.Results:After TT, serum PTH returned to normal value in most patients 1 month after operation. The proportion of PHP was 3.33% (5/150). Univariate analysis showed that bilateral central lymph node dissection, Hashimoto’s thyroiditis, tumor diameter ≥2 cm and intraoperative selective parathyroid autologous transplantation were risk factors for temporary hypoparathyroidism (THP). Multivariate analysis showed that BCND ( OR=0.322, P=0.001) , intraoperative selective parathyroid autograft ( OR=5.442, P=0.001) and tumor diameter ≥2 cm ( OR=2.247, P=0.003) were independent risk factors for THP. ROC curve was used to compare the predictive effect of postoperative serum and drainage PTH levels on postoperative PHP. The statistical results showed that the highest predictive effect of postoperative PHP was found on the first day of drainage PTH level within 1 week after operation (AUC 0.81) . 54 cases whose serum PTH was lower than normal value on the first day after operation were divided into 4 groups according to the level of PTH in drainage fluid from high to low. The results showed that the lower the level of PTH in drainage fluid, the greater the possibility of PHP ( P<0.05). Conclusions:Most of the patients with low PTH one month after operation develop PHP, while bilateral central lymph node dissection, intraoperative selective parathyroid transplantation, tumor diameter ≥2 cm are risk factors for THP after TT. If the serum PTH is lower than the normal value on the first day after operation, there is a possibility of PTH. The lower the PTH in the drainage fluid, the greater the possibility of PHP, which should be paid attention to in clinical practice.