Introduction
Along with the recurrent laryngeal nerve paralysis and bleeding, postoperative hypocalcemia is the major and most frequent complication that occurs after thyroid surgery1. Commonly it arises following removal or insult to the parathyroid glands at neck surgery2-6. Hypoparathyroidism is defined by a decrease in serum PTH and calcium levels: it may occur as a transient form (TtHP), with progressive normalization within six months from surgical treatment, or permanent (PtHP), whenever the patient continues to require replacement therapy 7,8. Numerous reports have attempted to correlate the incidence of post surgical complications with the type of thyroid disease associated, positive family history of thyroid cancer, gender of the patient, type of operation, cervical lymph nodes involvement, surgical expertise and surgical timing6, 9-13. The identification of fewer than two parathyroid glands during thyroidectomy is also associated with the development of hypocalcemia 14. Others have investigated the possible link between the development of transient hypocalcemia and low levels of preoperative vitamin D associated with low postoperative parathyroid hormone (PTH) 15-22. Another biochemical parameter which has been correlated with transient hypocalcemia is the post-operative serum magnesium concentration, independently of the serum calcium levels 23-26. The calcium level less than 1.88 mmol/l or lower after 24h from thyroid surgery has been reported as predictive for the development of permanent hypocalcemia 27-32. The risk factors identified by the scientific community are different, depending on TtHP or PtHP and are currently a matter of debate. In the present study the main end-point was to analyze, in a pediatric population following thyroid surgery, rate and factors associated with the development of TtHP or PtHP.