The use of ICG enhanced fluorescence for the evaluation of parathyroid gland preservation

Intraoperative Indocyanine Green (ICG) Angiography for the Identification of the Parathyroid Glands: Current Evidence and Future Perspectives

“…NIR ICG fluorescence imaging is a very promising method that can help surgeons to locate parathyroid glands in real-time during thyroid and parathyroid surgery. ICG has the advantage of accumulation in pathological PGs, which attributes to the higher fluorescence intensity compared to the surrounding tissues (9,18,30). However, ICG does not target specifically the parathyroid parenchyma.…”

“…Therefore, in thyroidectomies, except PG localization, their vascularity and therefore their viability is also a desired outcome. Transient hypoparathyroidism occurs in around 19-38% of cases, while permanent hypoparathyroidism is estimated at around 0-3% (30). This is caused by inadvertent injury, ischemia, gland devascularization or incidental excision of PGs due to failure in identifying and preserving them (9).…”

“…Postoperative hypoparathyroidism can cause prolonged hospitalization, neuromuscular symptoms, the need for lifelong calcium and vitamin D supplementation, cerebral, vascular, ocular and renal damage (9). It is worth to note that a variety of hypocalcemia and hypoparathyroidism PTH levels has been published, adding confusion to the respective comparison of definitions among the different studies (30).…”

“…As cited in the results section, there is a lack of standardization regarding the dose as well as the frequency and the timing of ICG administration, and all these parameters varied greatly in the reviewed articles. As outlined in Table I, many different devices are being used, while there are several technical factors in the various imaging systems that can affect the sensitivity levels of each device (30). Therefore, the big variation observed regarding the aforementioned parameters might be due to the various types of imaging equipment used (1).…”

“…The advantage of ICG fluorescent angiographic technology in identifying PGs greatly depends on the method to localize and assess PG function in a non-invasive manner (38). It is also of interest to note that following injection, the time of its appearance in the PGs was longer in the two articles using robotic surgery (16,18) while in the rest of the articles the PGs were visible from 15 sec -2 min (5,9,13,16,19) and the adenomas stayed fluorescent for about 20 min (4,12,30). Therefore, an overall consensus on the optimal dosage and timing of ICG administration is still lacking (18) and further studies are required.…”