Application of a Fluorescence Imaging System with Indocyanine Green to Protect the Parathyroid Gland Intraoperatively and to Predict Postoperative Parathyroidism.

Abstract

Identifying the parathyroid gland during surgery may be difficult for surgeons. It is critical for them to be able to locate it during thyroidectomy or parathyroidectomy because of the significant function of the parathyroid in the calcium balance. According to recent reports, intrinsic fluorescence of the parathyroid has been found. There is some evidence to suggest that new equipment can detect the fluorescence via imaging technology. In this study, a newly invented intraoperative fluorescence imaging system and indocyanine green (ICG) dye were applied to detect the parathyroid glands and evaluate the vascularization of the parathyroid. From 1 May to 8 August 2018, 26 patients underwent total thyroidectomy in Zhuhai People's Hospital. These 26 subjects were recruited in our research. All identified parathyroid glands were scored visually from grade 0 to grade 2 according to the vascularity of the parathyroid before ICG angiography was performed. After ICG angiography, the parathyroid glands were scored from 0 to 2 according to the fluorescence intensity (FI). Visual scores were significantly higher than ICG angiography scores. In the 22 patients with at least one parathyroid gland with an ICG score of 2, postoperative parathyroidism (PTH) levels were in the normal range. Of the four patients with no parathyroid gland with an ICG score of 2, two developed transient hypoparathyroidism, with recovery on postoperative day (POD) 7 for the first patient and after 3months for the second. This study has shown that a fluorescence imaging system applied with indocyanine green is a safe, easy and effective method to protect the parathyroid and predict postoperative parathyroidism. Chinese Clinical Trial Registry no. ChiCTR1800016864.