Airway management for laryngoscopic surgery in patients with a laryngeal tumor includes temporary tracheostomy, endotracheal intubation using a thin ETT, transglottic or intercricoid high-frequency jet ventilation, and LMA insertion [1, 3]. However, it has been reported that the polyp was dislodged by the ETT and airway obstruction occurred when the trachea was intubated . When high-frequency jet ventilation is performed, there are risks of complications such as subcutaneous emphysema and pneumothorax . An LMA has been used for airway protection, and introduction of a flexible laryngoscope via the LMA has been successfully used in patients with a laryngeal polyp [1, 5]. Thus, we considered that LMA insertion could avoid invasive tracheostomy and would allow surgery to be performed using a flexible bronchoscope.
However, it has been reported that LMA insertion itself can cause deformity of the vocal cords , possibly resulting in airway obstruction due to lodging of the polyp between the vocal cords as in our case. LMA insertion may thus exacerbate airway obstruction in patients with a laryngeal polyp in the glottis, and caution should be paid for LMA insertion in such patients. In our case, the polyp was smoothly swung inward into the trachea in inspiration and swung outward to the larynx in expiration through the vocal cords during spontaneous respiration without dyspnea. Accordingly, reduction of the volume of the polyp by using a flexible laryngoscope under mask ventilation with light sedation might have been another option. However, this procedure may also have the risk of unanticipated difficult airway due to accidental deep sedation, bleeding from the tumor and abrupt body movement caused by surgical intervention.
LMA insertion enables successful ventilation in a patient with airway obstruction due to several large laryngeal polyps . Thus, the use of an LMA contributes to the relief of airway obstruction in some patients with a large laryngeal polyp. However, LMA insertion also has a potential risk of exacerbating airway obstruction in such patients as shown in our case. Thus, when laryngoscopic surgery with a flexible laryngoscope through an LMA is planned in patients with laryngeal lesions, preparation should also be made for transcricoid jet ventilation and tracheostomy prior to surgery.