The role of carbon nanoparticles in identifying lymph nodes and preserving parathyroid in total endoscopic surgery of thyroid carcinoma.

AIM: To evaluate the efficacy of carbon nanoparticles (CNs) in identifying lymph nodes and preserving parathyroids in endoscopic total thyroidectomy (ETT) with central neck dissection (CND), and to further explore the role of CNs in recovering postoperative parathyroid function. METHOD Fifty-five patients with papillary thyroid carcinoma were randomized to either CN group (n = 28) or control group (n = 27). The primary outcome measures were pathological results (e.g., amount of incidental removed parathyroids and lymph nodes dissected) and follow-up results [e.g., recovery of serum calcium and parathyroid hormone (PTH) levels]. The secondary end-points were the rates of neuromuscular symptoms, in-hospital postoperative hormonal assay, and lymph node metastases. RESULTS A total of 193 lymph nodes in the CN group and 123 lymph nodes in the control group were detected. The mean number of detected lymph nodes was significantly higher in the CN group than in the control group (P = 0.009). Parathyroids were present in the thyroid or central nodal specimens of five patients, which were all in the control group. The control group had a relatively higher incidence of incidental parathyroidectomy compared to the CN group (P = 0.023). Compared to the CN group, the incidence of paresthesia was higher in the control group even if not statistically significant. During follow-up, the serum calcium levels were higher in the CN group than in the control group; however, there was no statistically significant difference. For the serum PTH levels, the CN group recovered rapidly to the preoperative levels, whereas the control group climbed steadily to the normal range. The serum PTH levels in the CN group were apparently higher than in the control group at 1 week and 1 month postoperatively. CONCLUSION CNs play an important role in protecting parathyroid glands, dissecting lymph nodes thoroughly, and promoting rapid recovery of parathyroid in ETT with CND (ChiCTR-TRC-14005042).