Cho, Jung-Hae1; Joo, Young-Hoon1; Cho, Kwang-Jae1; Sun, Dong-Il1; Park, Young-Hak1
1 Department of Otolaryngology Head Neck Surgery, The Catholic university of Korea, Seoul, Korea
Background and Objectives: Postoperative hypoparathyroidism is the most common complications after total thyroidectomy. It is difficult to predict which patients are prone to the development of permanent hypoparathyroidism. This study was designed to identify risk factors to develop permanent hypoparathyroidism in postoperative hypoparathyroidism.
Methods: We enrolled patients who underwent total thyroidectomy for papillary thyroid cancer. from January 2009 to December 2015. Permanent hypoparathyroidism was diagnosed if 1) serum PTH levels were below the normal range (PTH < 15) or 2) calcium and/or vitamin D supplementation were necessary to treat hypocalcemia for more than 12 months. Serum PTH, calcium, phosphorus and magnesium levels were recorded before operation, during the first 3 days, and during follow-up (1, 3, 6, and 12 months).
Results: Post thyroidectomy hypoparathyroidism occurred in 97 patients (25.3%) out of 383 total thyroidectomies. Of those patients, 27 (27.8% of post thyroidectomy hypoparathyroidism, 7.4% of total patients) experienced permanent hypoparathyroidism. Hypocalcemic symptoms in spite of IV calcium replacement, bilateral central neck dissection, and number of resected parathyroid gland were associated with permanent hypoparathyroidism (p < 0.005). Lower serum calcium level at 2 days after surgery were associated with permanent hypoparathyroidism (p < 0.005).
Conclusions: A serial measurement of serum iPTH after total thyroidectomy might be used as predictive marker in characterizing the high risk of permanent hypoparathyroidism. The subnormal level of serum calcium at 2 days after surgery might be associated risk factor for predicting permanent hypoparathyroidism.