Research on indocyanine green angiography for predicting postoperative hypoparathyroidism.

Background: It may be critical to locate the parathyroid for surgeons during thyroidectomy or parathyroidectomy due to the significant function of the parathyroid in calcium balance. According to recent reports, the intrinsic fluorescence of the parathyroid has been found. There is some evidence supporting that new equipment can detect fluorescence via imaging technology. In this study, a newly invented intraoperative fluorescence imaging system and indocyanine green dye were applied to detect the parathyroid glands and evaluate the vascularization of the parathyroid. The report is as follows.

Methods: From 1 May to 8 August 2018, 26 patients underwent total thyroidectomy in Zhuhai People's Hospital and were recruited into 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, parathyroid glands were scored from score 0 to score 2 according to the FI.

Results: 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 PTH levels were in the normal range. In the four patients with no parathyroid gland with an ICG score of 2, two of them developed transient hypoparathyroidism, with recovery on POD 7 for the first patient and after 3 months for the second one.

Conclusion: This study has identified that the fluorescence imaging system applied with indocyanine green is a safe, easy and effective method to protect the parathyroid and predict postoperative hypoparathyroidism. Registration number: ChiCTR1800016864.