Background: To assess the promise of surgical magnification and of intraoperative indocyanine green (ICG) assisted near-infrared fluorescence (NIRF) in improving parathyroid identification and viability assessment during thyroidectomy.
Methods: Prospective comparative study. Parathyroid gland identification sequentially assessed by naked eye, surgical microscopy, and by NIRF imaging following ICG administration (5 mgIV). Parathyroid perfusion/vitality reassessed end-surgery by ICG-NIRF. Results: An expected total of 104 parathyroid glands were assessed in 35 patients (17 total-thyroidectomy, 18 hemi-thyroidectomy). 54/104 (51.9%) were identified by naked eye, and sequentially greater numbers identified by microscope magnification (n = 61; 58.7%; p = 0.33), and by ICG-NIRF (n = 72; 69.2%; p = 0.01). ICG-NIRF detected additional parathyroid glands in 16/35 patients (45.7%). Confident identification of at least one parathyroid remained unachieved in 5/35 by naked eye, in 4/35 by microscopic magnification, and in no patient by ICG-NIRF. ICG-NIRF indicated end-of-surgery devascularization in 12/72 glands and informed decisions regarding gland implantation. Conclusion: Significantly greater parathyroid glands are identified and preserved with surgical magnification and with ICG-NIRF. Both techniques merit routine adoption for thyroidectomy.