Carbon Nanoparticle Technology for Parathyroid Gland Preservation during Thyroid Surgery: A Narrative Review

Postoperative hypoparathyroidism is a common complication of thyroid surgery, mainly due to inadvertent injury or removal of the parathyroid glands. The small size, anatomical variability, and subtle appearance of the parathyroid glands make their intraoperative identification and preservation challenging. In recent years, carbon nanoparticle suspensions (CNS) have shown promise in improving the accuracy of parathyroid preservation during thyroidectomy. This narrative review aims to summarise current evidence on the use of CNS in thyroid surgery, focusing on their mechanism of action, clinical efficacy, safety profile, and limitations. We conducted a narrative review of the literature addressing CNS use for parathyroid preservation in thyroid surgery. Outcomes of interest included rates of accidental parathyroidectomy, transient and permanent hypoparathyroidism, lymph node yield, and surgical complications. Carbon nanoparticles are selectively taken up by lymphoid and thyroid tissue but not by the parathyroid glands, creating a clear visual contrast that facilitates rapid intraoperative identification. Clinical studies and meta-analyses have shown that CNS use is associated with lower rates of accidental parathyroidectomy and transient hypoparathyroidism, along with increased lymph node retrieval. The safety profile is favorable, with adverse events being rare and mild. However, uncertainties remain regarding optimal administration protocols, long-term outcomes, and integration with other intraoperative tools. Carbon nanoparticle technology represents a promising adjunct for improving parathyroid preservation during thyroidectomy. While current evidence supports its clinical value, further research is needed to refine application techniques and establish standardized guidelines for broader use.