**Author details**

refined operational instruments. In this study, TT and CND were mostly performed under direct vision with the operator's headlight (mPack LL, HEINE Optometrik, Germany), and the first assistant's coordinated traction was emphasized; in addition, the use of a high-frequency electric knife with a needle-shaped head (Changzhou Yanling Electronic Equipment Co. Ltd., Jiangsu, China) and a small titanium ligating clip (Horizon; Weck Drive, Research Triangle Park, NC 27709, USA) are strongly recommended to preserve the

**6.** As mentioned earlier, when the RLN traverses between the ITA branches and the carotid artery, the paratracheal dissection can be divided into two parts according to the level of the ITA: a dissection cranial to the ITA (between the cricoid cartilage and ITA level) and one caudal to the ITA (between the innominate artery and ITA level), for completeness of dissection and RLN preservation (**Figure 11B**). Actually, the dissection between the cricoid cartilage and ITA level is a challenge because superior parathyroid gland and its blood supply from ITA and RLN are on this area. Although some surgeons declare that performing the dissection inferiorly from the trunk of ITA could achieve the equal completion of the dissection in safety [20, 21] because the metastatic lymph nodes are rarely found above the ITA trunk, the recurrence can be observed in this region between the cricoid cartilage and the ITA trunk. Therefore, the dissection in this region (between the cricoid cartilage and ITA level) should be emphasized, especially when the concept of "a layer of TBP" is performed. In addition, the usage of carbon nanoparticles, as a lymph tracer, can facilitate

The prevention of postoperative hypoparathyroidism entails several issues, including the concept of meticulous operation, the ability of parathyroid gland identification, the technique of parathyroid gland autotransplantation, and the principle of "the preservation of at least one vascularized parathyroid gland" [10, 22]. This chapter shows that the concept of "a layer of TBP" during CND can greatly improve the success rate of IPTG preservation in situ, thereby efficiently decreasing the incidence of temporary postoperative hypoparathyroidism, along

The authors thank their colleagues: Dr. Yuwen Miao and Dr. Lei Jin for supporting this clinical work, and other members of the Department of Head and Neck Surgery for helpful

parathyroid gland and its blood supply.

this procedure (not published).

with ensuring the completeness of lymph node dissection.

**5. Conclusion**

28 Thyroid Disorders

**Acknowledgements**

The author declares no conflict of interest.

discussions.

**Disclosure**

Lei Xie\*, Jianbiao Wang and Liang Zhou

\*Address all correspondence to: xiel@srrsh.com

Department of Head and Neck Surgery, Institute of Micro-Invasive Surgery of Zhejiang University, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China
