Safety of Ligasure exact dissector in thyroidectomy with continuous neuromonitoring: a porcine model

Tzu-Yen Huang; Yi-Chu Lin; Hsin-Yi Tseng; Gianlorenzo Dionigi; Hoon-Yub Kim; I-Cheng Lu; Pi-Ying Chang; Feng-Yu Chiang; Che-Wei Wu

doi:10.21037/gs.2020.03.17

Safety of Ligasure exact dissector in thyroidectomy with continuous neuromonitoring: a porcine model

Gland Surg. 2020 Jun;9(3):702-710. doi: 10.21037/gs.2020.03.17.

Authors

Tzu-Yen Huang^{1

2}, Yi-Chu Lin¹, Hsin-Yi Tseng¹, Gianlorenzo Dionigi³, Hoon-Yub Kim⁴, I-Cheng Lu^{5

6}, Pi-Ying Chang⁶, Feng-Yu Chiang^{7

8}, Che-Wei Wu^{1

5

9}

Affiliations

¹ Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
² Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan.
³ Division for Endocrine and Minimally Invasive Surgery, Department of Human Pathology in Adulthood and Childhood "Gaetano Barresi", University Hospital G. Martino, University of Messina, Messina, Italy.
⁴ Department of Surgery, KUMC Thyroid Center, Korea University Hospital, Korea University College of Medicine, Seoul, Korea.
⁵ Faculty of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
⁶ Department of Anesthesiology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
⁷ School of Medicine, College of Medicine, I-Shou University, Kaohsiung, Taiwan.
⁸ Department of Otolaryngology, E-Da Hospital, Kaohsiung, Taiwan.
⁹ Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.

Abstract

Background: The purpose of this study was to investigate and define safety parameters for using the Ligasure exact dissector (LED) for dissection close to the recurrent laryngeal nerve (RLN) during thyroidectomy.

Methods: Real-time electrophysiologic electromyographic (EMG) tracings were recorded in 16 RLNs (8 piglets) during various applications of LED under continuous intraoperative monitoring in this prospective porcine model study. In the activation study, LED was activated at varying distances from the RLN. In the cooling study, LED was activated with different cooling times or after touching the sternocleidomastoid muscle before application to the RLN.

Results: In the activation study, no adverse EMG events occurred at distances longer than 1 mm. In the cooling study, no adverse EMG events occurred after a 2-second cooling time. Additionally, no adverse EMG events occurred when a sternocleidomastoid muscle touch maneuver was used for cooling.

Conclusions: The LED can be safely used at distance of 1 mm or longer, and it should be cooled for at least 2 seconds or by muscle touch maneuver. Thyroid surgeons can avoid RLN injury if standard procedures for LED use are observed.

Keywords: Ligasure exact dissector (LED); Recurrent laryngeal nerve (RLN); continuous neuromonitoring; nerve thermal injury; thyroid surgery.