Abstract: Objective To introduce a new method to identify and protect the parathyroid glands in thyroid surgery with autofluorescence imaging. Methods A total of 6 patients who underwent thyroid surgery at our department in June 2020 were enrolled. The preoperative parathyroid hormone, serum calcium and phosphorus measurements were within the normal range. For the 3 patients with nodular goiter, 1 received thyroid lobectomy, and 2 received total thyroidectomy. Three patients with papillary thyroid carcinoma underwent total thyroidectomy, 2 of whom received simultaneous central lymph nodes dissection, and 1 received simultaneous lymph nodes dissection of central area + unilateral neck. Fluorescence surgical navigation system was used to perform autofluorescence imaging of parathyroid glands at the following time points: after the thyroid glands were exposed, after the parathyroid glands were exposed, after thyroidectomy, and after the completion of central lymph node dissection. Results Twenty-two parathyroid glands in 6 patients were not detected with autofluorescence before being exposed, but could be detected with obvious autofluorescence after being exposed. The autofluorescence imaging rate was 100%. The thyroids, lymph nodes and adipose tissues did not show substantial autofluorescence. One parathyroid gland still showed autofluorescence after being isolated. Conclusion Parathyroid glands show autofluorescence characteristics in the near-infrared spectrum. This can help to identify the parathyroid glands during thyroidectomy, but cannot be used as a navigation tool for parathyroid recognition.

Key words: Parathyroid gland, Autofluorescence, Near-infrared light, Thyroidectomy