Laryngomicrosurgery requires deep paralysis and general anesthesia to finish the procedure. After the procedure, patients need a long time to recover. In the present study, with the support of the transnasal humidified rapid-insufflation ventilatory exchange, laryngomicrosurgery would be finished under nonintubated deep paralysis (NIDP) general anesthesia. In this case series study, the investigators will test the safety and feasibility of such a technique.

Inclusion Criteria:

• elective polypectomy of unilateral vocal cord
• age between 18 to 40
• be able to communicate
• estimated operation time less than 15min
• ASA I-II
• Agree to sign written informed consent

Exclusion Criteria:

• pregnancy or breastfeeding women
• severe gastrointestinal reflex disease
• neuromuscular disease
• body mass index(BMI)>30
• predictable difficult airway.
• allergy to medicine would be used in the present study including propofol, remifentanil or sugammadex

Young patients who will under elective polypectomy of unilateral vocal cord.