Intraoperative identification of parathyroid glands by autofluorescence on total thyroidectomy – Does it really reduces post-operative hypocalcemia?

Abstract Background Intraoperative identification of parathyroid glands which remains largely dependent on the surgeon's expertise, is a major challenge in endocrine surgery and the most efficient way to reduce postoperative hypocalcemia and its important morbidity. Since the description on autofluorescence of parathyroid glands by Paras et al in 2011, other works had confirmed the utility of this property in the identification of the glands but its efficacy in reducing hypocalcemia is not completely stated. In this study we evaluate the utilization of a low-cost device in total thyroidectomy. Methods In a before and after controlled study we compared patients submitted to total thyroidectomy by the same surgeon in two periods: From January 2017 to February 2018 (visual identification of parathyroid glands) and from February 2018 to December 2019 (with utilization of the near infrared system). Main outcomes included postoperative hypocalcemia and hypoparathyroidism, parathyroid identification and incidental resection. Results Patients in the study group displayed significantly lower postoperative hypoparathyroidism (p=0.044). In spite of the reduction observed in study group absolute values of calcium and number of hypocalcemic patients didn't achieve statistical significance. There were no patients with permanent hypocalcemia in study group comparing with 3 in the control group. Number of parathyroid glands identified was significantly higher in study group (p Near infrared autofluorescence device was able to identify accurately inadvertently removed parathyroid glands, with a sensivity of 100% and a specificity of 87.5 %. Conclusions Event though we couldn't demonstrate significant improvement in transient postoperative hypocalcemia, the reduction of permanent hypocalcemia and the improvement in surgeon's ability and confidence in the identification of parathyroid glands could make near infrared autofluorescence an useful tool in surgery of thyroid gland.