*3.4. Parathyroid Gland Visualization and Preservation*

Twenty-three studies reported on the visualization and/or preservation of the PGs during thyroid surgery. Four of these studies [45,49,51,53] demonstrated improved visualization of the PGs using fluorescence imaging compared with conventional thyroid surgery. However, van den Bos et al. [23] showed better visualization with white light compared with NIR imaging. Lerchenberger et al. [54] reported that although autofluorescence demonstrated slightly better visualization of the PGs, it could not indicate whether the blood supply to the gland was still viable, in contrast to the use of ICG. Several studies also reported that fluorescence was used to identify PGs in resected segments or those whose blood supply had been disrupted, which were autotransplanted [57,60,62,67]. In the larger series of Kim et al. (542 patients), no statistical difference in PG visualization was observed between an NIRAF group and the control group (3.91 ± 0.36 vs. 3.90 ± 0.39; *p* = 0.351) [66]. Enny et al. [47] reported better visualization of the PGs using the naked eye than using fluorescein dye, although the difference was not significant. Corresponding data are shown in Table 4.

**Table 4.** Parathyroid gland visualization and preservation, postoperative serum parathyroid hormone levels, and postoperative serum calcium levels.




PG—Parathyroid gland; ICG—Indocyanine green; NIRI—Near-infrared imaging; POD—postoperative day; AF—autofluorescence; NIRAF near-infrared autofluorescence.
