Does the use of near-infrared autofluorescence reduce the incidence of inadvertent parathyroidectomy during thyroid surgery?—a pilot study in an Australian centre

Background: The incidence of inadvertent parathyroidectomy in thyroid surgery may vary from 6.4% to 31%, depending on factors such as surgeon experience and case complexity. It has recently been identified that endogenous fluorophores in parathyroid tissue exhibit auto-fluorescence in the near-infrared (NIR) spectrum. This property may be utilized to enhance detection of parathyroid glands during thyroid surgery, through the use of endoscopes containing a NIR filter. It is proposed that such adjuncts may assist in reducing inadvertent parathyroidectomy and post-operative hypocalcaemia rates. The aim of this study is to determine if there is a significant difference in advertent parathyroidectomy rates between routine naked eye detection, and use of NIR. Methods: This retrospective cohort study analysed patients who underwent hemi or total thyroidectomy at Logan Hospital, Brisbane, Australia, between 2019 and 2024. The incidence of inadvertent parathyroidectomy and post-operative hypocalcaemia were compared in cases where NIR was used as an adjunct versus standard naked-eye detection. NIR was performed using an indocyanine green (ICG) rigid endoscope with a Rubina camera head, to assist dissection and verify parathyroid tissue. The primary outcome analysed was incidence of inadvertent parathyroidectomy. The secondary outcome was postoperative hypocalcaemia rates in total thyroidectomy cases. Results: A total of 171 cases were reviewed. Among 154 cases using routine naked eye detection, there were 26 instances of inadvertent parathyroidectomy (16.8%). In the 17 cases using NIR, only 1 case of inadvertent parathyroidectomy was recorded (5.9%). The difference in inadvertent parathyroidectomy rates between the two groups was not statistically significant [P=0.48; odds ratio (OR) =0.31; 95% confidence interval (CI): 0.04–2.42]. Postoperative hypocalcaemia was observed in 67% of NIR patients and 47% of standard detection patients. This difference was not statistically significant (P=0.66; OR =2.24; 95% CI: 0.36–13.78). The use of NIR did facilitate the re-implantation of parathyroid tissue in one case, where a parathyroid was identified on the excised thyroid specimen. Conclusions: This study suggests that NIR may offer a useful adjunct to naked-eye detection in thyroid surgery. While the difference in inadvertent parathyroidectomy and post-operative hypocalcaemia rates between the NIR and standard groups was not statistically significant, NIR demonstrated the potential to assist in the early identification and preservation of parathyroid tissue. This could be particularly beneficial in complex cases, such as those involving central neck dissection or when parathyroid tissue is difficult to differentiate from surrounding structures. Given the safety, low additional cost, and ease of integration into routine practice, the use of NIR autofluorescence should be considered in thyroid and parathyroid surgery. Larger, prospective studies are needed to validate these findings and explore the long-term impact of the application of NIR technology on surgical outcomes.