Carbon nanoparticles guide contralateral central neck dissection in patients with papillary thyroid cancer

Preoperative application of carbon nanoparticles in bilateral axillo-breast approach robotic thyroidectomy for papillary thyroid cancer

BACKGROUND

Carbon nanoparticles (CNs) have been used intraoperatively in open thyroid surgery to facilitate central neck dissection and parathyroid protection. However, little attention was paid to the preoperative injection of CNs. Its safety and feasibility remain to be evaluated in bilateral axillo-breast approach robotic thyroidectomy (BABA RT).

METHODS

In this retrospective cohort study, 114 papillary thyroid cancer patients (PTC) undergoing BABA RT were enrolled from March 2020 to March 2021. In the CNs group (n=64), 0.15 mL of CNs was injected into the thyroid lobules with malignant nodules the day before surgery. Medical records were reviewed and analyzed, including complications of CNs usage, surgical outcomes, central lymph node (CLN) retrieval, and parathyroid glands (PGs)-related parameters.

RESULTS

No significant differences were found between the CNs and the control groups in terms of general characteristics and surgical parameters. Complications of CNs were rare in the CNs group. The mean number of retrieved CLN was significantly higher in the CNs group than in the control group (9.48±4.88 vs. 5.40±2.67, P<0.001), as was the mean number of metastatic CLN (2.00±2.56 vs. 1.04±1.70, P=0.018). There were no differences in PGs preserved in situ, PGs autotransplantation, and postoperative PTH levels on the first day and first month (all P>0.05).

CONCLUSIONS

In patients with PTC undergoing BABA RT, preoperative application of CNs is a safe and feasible method to facilitate central neck dissection. However, the value of the preoperative application of CNs in robotic thyroidectomy needs to be further studied because it has no significant benefit for parathyroid protection.

Preoperative Visualized Ultrasound Assessment of the Recurrent Laryngeal Nerve in Thyroid Cancer Surgery: Reliability and Risk Features by Imaging

Background

Preoperative identification and visualization of tumor infiltration of the recurrent laryngeal nerve (RLN) in patients with thyroid cancer is important. The purpose of our study was to evaluate the reliability and feasibility of preoperative assessment by ultrasound and to identify ultrasound imaging features potentially associated with tumor infiltration of the RLN.

Methods

In this prospective study, patients undergoing thyroid cancer surgery at our institution between August 2020 and January 2021 were included, and preoperative ultrasound visualization of the RLN and thyroid lesions was performed. RLN infiltration was also confirmed surgically in all cases. Five patients with enlarged lymph nodes were selected to undergo injection of carbon nanoparticles to confirm the correctness of RLN identification by preoperative ultrasound. The repeatability of RLN assessment by ultrasound was evaluated by comparing the correlation between pre- and intraoperative, intra- and inter-group assessments. Parameters of normal RLNs according to age, sex, and body mass index were established. Finally, ultrasound imaging features of patients with RLN tumor infiltration were analyzed to identify potential risk predictors.

Results

According to the ultrasonic assessment, RLNs of 70 patients appeared normal, while 14 of those patients appeared to be infiltrated by tumors. During surgery, the 70 cases of normal RLNs were confirmed, but only 8 of the 14 suspected cases of infiltration were confirmed. In all five patients injected with carbon nanoparticles, the location of RLNs adjacent to the marked lymph nodes observed by surgeons corresponded to the RLN location identified by preoperative ultrasound. The repeatability of RLN estimation varied from moderate to excellent. There were no significant differences in cross-sectional area, width, or thickness of normal RLNs according to age, sex, or body mass index. Indistinct margin with tumor, incontinuous shape as ultrasound features by the analysis of patients with surgically confirmed RLN infiltration were associated with tumor invasion.

Conclusion

We show that preoperative ultrasound can be applied to visualize the RLN and may help predict tumor infiltration of the RLN.

Infiltration of nanocarbon suspension into the tracheal cavity during surgical treatment of papillary thyroid carcinoma: a case report

Cervical lymph node metastasis in patients with differentiated thyroid cancer affects postoperative recurrence and survival. Hypoparathyroidism is caused by parathyroid gland injury during thyroidectomy. Carbon nanoparticles can trace stained lymph nodes, aiding in thorough dissection of lymph nodes in the operation area. To reduce postoperative occurrence of hypoparathyroidism, the parathyroid glands and their functions (identified by negative imaging induced by carbon nanoparticles) are retained in situ. However, the safety and adverse effects of nanocarbon suspension in thyroid surgery have rarely been evaluated. In this report, we describe a patient with thyroid cancer who had carbon secretions in the trachea caused by nanocarbon suspension when tracheal intubation was performed under general anesthesia, and the inflatable balloon surface of the tracheal tube was covered with these secretions. The patient recovered without fever, cough, phlegm production, chest pain, hoarseness, or hypocalcemia-induced convulsions. No consensus has yet been reached on the most appropriate injection site, depth, dose, or waiting time for nanocarbons in thyroid cancer surgery. We believe that nanocarbon suspension is safe for use in thyroid cancer surgery, but the most appropriate injection depth should be based on the thickness of the thyroid gland tissue to avoid deep injection into the trachea.

Do carbon nanoparticles really improve thyroid cancer surgery? A retrospective analysis of real-world data

Background

Parathyroid protection and central neck dissection (CND) are basic points of thyroid cancer surgery and draw persistent concern. We aimed to evaluate the value of carbon nanoparticles (CNs) for parathyroid gland protection and CND in thyroid surgery for thyroid cancer patients.

Methods

A total of 386 consecutive thyroid cancer patients were enrolled in the retrospective study. Three hundred thirty-four patients using CNs intraoperatively were included in the CN group, and 52 patients without using CNs or any other helping agent were included in the control group. Intact parathyroid hormone (iPTH) was examined. Medical records and histopathologic reports were reviewed. Histopathologic examination was performed.

Results

There were no statistical significances in demographic and basic surgical information, preoperative iPTH, and serum calcium between the two groups (P > 0.05). In the CN group, the thyroid tissue and central neck lymph nodes were stained black by CNs, while the parathyroid glands were not. Histopathological examination showed that the carbon nanoparticles might accumulated in the subcapsular sinus of lymph nodes compared with the none-stained samples. The staining with CNs did not impact the histopathological examination. There were no significant differences in postoperative hypocalcemia and hypoPT at day 1, 1 month, and half year after surgery between the two groups, respectively. There was a big decline of iPTH level after surgery, whereas the perioperative decreasing amplitude of PTH was not statistically different between the CNs and control group (57.2 ± 28.6 vs 55.7 ± 27.8, P = 0.710). There were 43 patients occurring incidental parathyroidectomy in the CN group (43/334, 12.9%) and 7 patients in the control group (7/52, 13.5%), without significant difference (P = 0.907). There was no significant difference in the number of lymph nodes identified by pathology per patient between the CNs and control group regardless of unilateral and bilateral CND.

Conclusions

Carbon nanoparticles help highlight parathyroid glands and lymph nodes in thyroidectomy, but generate no significant benefit for parathyroid glands protection and lymph node dissection. The value of carbon nanoparticles in thyroid cancer surgery should not be exaggerated and needs further evaluation.