[Factors affecting the near-infrared autofluorescence intensity of parathyroid glands and intraoperative identification of parathyroid glands].

Objective: To evaluate the potential factors influencing the parathyroid autofluorescence intensity of near-infrared fluorescent (NIRF) and further value of NIRF in identifying the parathyroid during surgery. Methods: The clinical data of 51 patients who underwent thyroid or parathyroid surgery in the Department of Thyroid Surgery, the First Affiliated Hospital of Zhengzhou University from April to June 2019 were retrospectively analyzed, including 16 males and 35 females, aged 18 to 74 years.The fluorescence intensity (FI) of the parathyroid glands, thyroid glands and background, and the number of parathyroid glands detected by NIRF and white light were measured. Variance analysis, two independent samples t test and Spearman rank correlation analysis were used to analyze the relationship between standardized parathyroid FI and clinical variables. Chi square test was used to analyze the difference of parathyroid detection rate between NIRF and white light. Results: In the 51 patients, the mean standardized parathyroid FI was greater than the standardized thyroid FI (1.72 ± 0.68 vs. 1.25 ± 0.40, t=6.555, P<0.001). The standardized parathyroid FI was not associated with gender, age, operation type, BMI, preoperative serum Ca(2+), parathyroid hormone and calcitonin (all P>0.05), but it was associated with disease type (F=2.636, P<0.05). The mean standardized parathyroid FI of SHPT was lower than that of PTC, PTC with nodular goiter or NG(0.70±0.28 vs. 1.86±0.70, 1.69±0.49, 1.64±0.44, t value was 3.023, -1.129,-2.019, respectively, all P<0.05). There was no difference in the standardized parathyroid FI between SHPT and PHPT (1.34±0.18, t=1.218, P>0.05). There was no difference in standardized parathyroid FI between PHPT, PTC, NG, and PTC with NG(all P>0.05). Except for 3 cases of SHPT, 117 parathyroid glands were detected by NIRF and 101 parathyroid glands were detected by white light. The detection rate of parathyroid glands detected by NIRF was higher than that detected by white light (98.32% vs. 84.87%, χ(2)=13.974, P<0.001). In SHPT, the detection rate of parathyroid gland by NIRF was 25.00%. Conclusions: Except SHPT, parathyroid FI is not affected by other clinical variables. NIRF can improve the detection rate of parathyroid glands during operation.