Abstract

Background: Hypoparathyroidism is a frequent complication of thyroid surgery, its incidence in the literature varies from 1.6% to more than 50% of cases. It is a major cause of prolonged hospital stays requiring long-term calcium supplementation for some patients and very close clinical and biological post-operative follow-up.

Purpose: The purpose of this study is to determine the prevalence of hypocalcaemia in thyroid surgery through our experience of ENT and CFC service at the Rabat specialty hospital and the predictive factors for its occurrence.

Materials and Methods: This is a prospective, analytical study of patients undergoing total thyroidectomy over a period from April 2016 and November 2018. This study was carried out within the ORL and CCF department at the Rabat specialty hospital in Morocco. Outcome measures were initial postoperative hypocalcemia defined as serum calcium below 2.0 mmol/l after total thyroidectomy within 48h and persistent hypocalcemia defined as serum calcium below 2.0 mmol/l above six months and/or the need for additional calcium and vitamin D supplementation.

Results: Initial postoperative hypocalcemia was present in 62 of 240 patients (25.83%) with 72 out of 240 patients (30%) developing symptoms. 21 patients (8.75%) had a persistent hypocalcemia above six months. In the binary logistic regression analysis, Central neck dissection (OR 2.2; CI95% 1.3 - 3.8), Prolonged surgery time > 189 minutes (OR 1.6; CI95% 1.1 - 2.1) and Malignant anatomopathological diagnosis (OR 1.5; CI95% 1.2 - 2.2) were associated with initial hypocalcemia while only central neck dissection was shown to be independently associated with persistent hypocalcemia (OR 12.32; CI95% 7.56 - 23.34).

Conclusion: Post thyroidectomy hypocalcemia constitutes a diagnostic and therapeutic emergency, and its prevalence remains high. Good knowledge of the predictive factors will allow any surgeon to avoid as much as possible the occurrence of hypoparathyroidism after thyroid surgery.

Keywords: Hypoparathyroidism; Hypocalcemia; Total Thyroidectomy

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