Introduction: Thyroidectomy for thyroid cancers and central neck dissection are considered as independent predictors of postoperative hypocalcemia. Post-surgical hypocalcemia is the most common and often the most difficult long-term consequence of thyroid surgeries. Management of hypocalcemia is done with calcium supplementation, but there is no consensus on the timing and the amount of calcium supplementation.
Materials and methods: A retrospective study of all thyroid cancer patients who underwent total thyroidectomy at our Centre, from August 2009 to August 2017 was done to evaluate the prevalence of symptomatic hypocalcemia. The patients were grouped into two based on the early and late supplementation of calcium in the form of intravenous calcium gluconate and oral calcium with calcitriol.
Results: There were 133 patients of which 109 had papillary carcinoma, 11 had follicular, 3 had hurthle cell and 10 had medullary carcinoma. Of these, 49.6% underwent total thyroidectomy alone and the rest with neck dissection. 38 patients (28.6%) had a unilateral neck dissection and 16 patients (12%) had a bilateral neck dissection. 14 out of the 67 patients (20.9%) who underwent neck dissection developed symptomatic hypocalcaemia, in contrast to only 2 patients out of the 66 (3%) without neck dissection. 31.7% of lateral neck dissection and 7.7% of central compartment dissection had symptomatic hypocalcaemia (p value = 0.0053). 22.5% of patients whose parathyroid were not identified had more symptomatic hypocalcaemia than in whom at least one parathyroid gland was seen (p value=0.0004). Eleven out of 73 patients (15.1%) who were treated late with calcium and calcitriol, and one out of 60 (1.7%) who had early calcium supplementation developed symptoms (p value=0.0073).
Conclusion: Central compartment and lateral neck dissection were significantly associated with higher incidence of symptomatic hypocalcemia. Early intervention with calcium supplementation reduced the symptoms of hypocalcemia. Identification and preservation of parathyroid glands significantly reduces the hypocalcemia.