The key to a successful microlaryngoscopy is adequate operative field exposure and illumination. A variety of airway control procedures has been developed to improve operative exposure. A small size endotracheal tube is commonly used. However, some surgeon may suggest a 'no-tube' technique to optimize the surgical field. This study aims to investigate effectiveness and safety of a novel technique by supraglottic jet oxygenation and ventilation (SJOV) via nasal approach to facilitate optimal visualization in laser microlaryngeal surgery for small vocal polyps resection.

The allocation sequence is generated by computer random number generation, and the allocation is placed in sequentially numbered opaque sealed envelopes by a non-investigator. Enrolment and data collection are performed by trained research staff who are not involved in the care of the patients. The treating clinicians are not possible to be blinded to the assignment group, but all other staff involved in both the collection and collation of data, and administration of neurocognitive testing, are blinded to group allocation.

The primary measurement is numerical rating scale (NRS) rated by surgeon according to surgical exposure and visualization. The secondary measurements are operation duration, and Intraoperative pulse oximetry (SpO2), PetCO2.

The continuous variables were expressed as means ± standard deviation (SD) whereas categorical variables were expressed as frequency and percentage for data description.

Inclusion Criteria:

• Patients scheduled for laser laryngeal surgery under general anesthesia

Exclusion Criteria:

• Patients with cardiac, pulmonary, hepatic, or renal dysfunction. Patients with nasal disease. Patients with anticipated difficult airway.