The Potential Role of Carbon Nanoparticles in Lymph Node Tracing, Recurrent Laryngeal Nerve Identification and Parathyroid Preservation During Thyroid Surgery: A Systematic Review

Background/Objective: Carbon nanoparticles (CNs) are a novel injected suspension used during thyroidectomy in order to black stain the thyroid gland and the lymph nodes while maintaining the anatomic color of the parathyroid glands and the laryngeal nerves. The aim of this systematic review is to investigate the benefits of carbon nanoparticles in thyroid surgical procedures and examine their role in lymph node tracing, parathyroid preservation, and recurrent laryngeal nerve protection. Methods: A systematic review of the literature in the PubMed/Medline database was performed. Articles reporting randomized clinical trials, prospective, and retrospective studies that compared the use of carbon nanoparticles in one group of patients with a control-blank group were included. The article was reported in accordance with PRISMA guidelines (CRD42021243015). Results: The search strategy retrieved 22 studies of the literature. Fourteen studies calculated a greater number of lymph nodes detected/dissected in the central neck zone to the patients using CN solution and 1 article noted a higher rate of lymph nodes resected in the lateral neck zone in the same group of patients. A significant increase in the number of metastatic lymph nodes retrieved in the CN group was found in 7 studies. Twenty-one studies suggested that the use of CNs for the protection of the parathyroid glands was beneficial. Transient hypoparathyroidism and transient hypocalcemia were presented with a significantly lower incidence in the CN group in 13 and in 8 studies, respectively. Conclusion: Carbon nanoparticles may improve both central and lateral neck dissection and enhance parathyroid gland identification and preservation.