Open label randomized controlled study, for Harmonic versus Ligasure in transoral endoscopic thyroid surgery.

• This is a prospective randomized controlled study. The principal investigator or another clinical investigator in charge will individually inform the patients about the study, on the day before surgery.
• When informed consent is obtained, an investigator in charge of randomization only, will randomize the patients.
• According to randomization, the experimental group will Ligasure and the control group will use Harmonic ACE 7+. Other than the randomized use of energy devices, the protocol for TOETVA is performed as usual.
• Operation time (from insertion of the laparoscopic camera to removal of the camera), number of times the camera was cleaned, intraoperative blood loss will recorded.
• Postoperative hospital stay, visual analog pain scale, blood cell count and inflammatory parameters, postoperative drain amount will recorded.
• Complications of thyroid surgery (vocal cord dysfunction, hypoparathyroidism) are compared for safety assessment.

Inclusion Criteria:

• Patients who planned to transoral endoscopic thyroidectomy
• Age between 20 to 70
• Voluntarily consenting to the study and study agreement
• No local invasion or distant metastasis
• Normal vocal cord function in laryngoscopic exam
• No significant abnormalities in preoperative laboratory tests

Exclusion Criteria:

• Take aspirin or antiplatelet drugs within 7 days before admission
• Uncontrolled hypertension, diabetes, chronic renal failure, or coagulation disease
• History of cardiovascular disease (angina pectoris, heart failure, myocardial infarction, history of coronary artery disease, stroke, transient ischemic attack)
• Substance abuse and alcohol abuse
• History of esophageal and airway diseases
• Patient was participated in other clinical trials within 30 days
• History of neck irradiation or surgery
• History of severe drug allergies
• Pregnant or lactating women