Incremental value of magnification and indocyanine green for parathyroid preservation in thyroid surgery

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.

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.

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.

Significantly greater parathyroid glands are identified and preserved with surgical magnification and with ICG-NIRF. Both techniques merit routine adoption for thyroidectomy.