Risk factors of postoperative hypoparathyroidism after total thyroidectomy in pediatric patients with thyroid cancer

Choe, Yunsoo; Lee, Yun Jeong; Shin, Choong Ho; Chung, Eun-Jae; Lee, Young Ah

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Ann Pediatr Endocrinol Metab > Accepted Articles

Original article

DOI: https://doi.org/10.6065/apem.2244044.022 [Accepted] Published online June 28, 2022.

Risk factors of postoperative hypoparathyroidism after total thyroidectomy in pediatric patients with thyroid cancer

Yunsoo Choe¹

, Yun Jeong Lee¹, Choong Ho Shin¹, Eun-Jae Chung², Young Ah Lee¹

¹Department of Pediatrics, Seoul National University, Seoul, Korea
²2Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University, Seoul, Korea

Address for correspondence: Young Ah Lee
Email: nina337@snu.ac.kr

Received: February 22, 2022 Revised: March 30, 2022 Accepted: April 8, 2022

Abstract

Purpose
Hypoparathyroidism is the most common complication following thyroidectomy. We investigated the frequency and risk factors of hypoparathyroidism after total thyroidectomy in pediatric patients with thyroid cancer.
Methods
This retrospective study included 98 patients, diagnosed with thyroid cancer after total thyroidectomy < 20 years of age during 1990―2018 and followed up more than 2 years at Seoul National University Hospital. Hypoparathyroidism was defined as receiving active vitamin D (1-hydroxycholecalciferol or 1,25-dihydroxycholecalciferol) after surgery.
Results
The study included 27 boys (27.6%) and 71 girls (72.4%). The mean age at diagnosis was 14.9 ± 3.7 years. Hypoparathyroidism occurred in 43 (43.9%) patients. Twenty-one (21.4%) patients discontinued active vitamin D less than 6 months, and 14 (14.3%) continued active vitamin D for more than 2 years. Tumor multifocality (Odds ratio (OR) 3.7 vs. single tumor, P=0.013) and preoperative calcium levels (OR 0.2, P=0.028) were independent predictors for developing hypoparathyroidism immediately after total thyroidectomy. In addition, age (OR 0.8, P=0.011) and preoperative calcium levels (OR 0.04, P=0.014) significantly decreased the risk for persistent hypoparathyroidism requiring active vitamin D for more than 2 years.
Conclusion
Hypoparathyroidism occurred in about two-fifth after total thyroidectomy in pediatric thyroid cancer. Among them, one-third of patients continued active vitamin D medication for more than 2 years, which was predicted by young age and low preoperative calcium levels.

Keywords: Thyroid neoplasms, Thyroidectomy, Hypoparathyroidism, Hypocalcemia, Parathyroid hormone