Hypoparathyroidism following thyroidectomy: Predictive factors

Abstract Objective To evaluate the incidence and predictive factors for transient and permanent hypocalcemia and hypoparathyroidism following thyroidectomy. Method We studied all the 162 patients that underwent thyroid surgery in the ENT department of the Centro Hospitalar Vila Nova Gaia/Espinho from January 2005 to December 2014. We reviewed pre-operative, 6 h and 12 h after surgery ionized calcium and PTH levels. All patients were reviewed and evaluated according to the following criteria: gender, age, thyroid function, histologic diagnosis of the specimen, surgery extension and presence or absence of hypoparathyroidism. Results There were 31 (19.1%) cases of transient hypoparathyroidism and 8 (5%) of permanent hypoparathyroidism. No significant difference was found for transient hypoparathyroidism when patients were analyzed by gender. However, all cases of permanent hypoparathyroidism were observed in female individuals. Comparing hemithyroidectomy with all other surgical procedures, we found that extension of surgery was a great predictor of transient ( p  = 0.0001) and permanent ( p  = 0.001) hypoparathyroidism. Diagnosis of malignancy was a strong predictor of transient hypoparathyroidism ( p  = 0.002). It was also associated with permanent hypoparathyroidism, although differences did not reach statistical significance ( p  = 0.096). Conclusion Extension of surgery (total thyroidectomy) and diagnosis of malignancy are predictors of transient and permanent hypoparathyroidism.