LAUSR

Endoscopic submucosal dissection (ESD) is a minimally invasive surgery for laryngeal cancers [1], during which nerve sparing is necessary to preserve function [2]. The internal branch of the superior laryngeal nerve (ibSLN) enters the parietal recess mucosa and is distributed in the submucosa of the larynx and hypopharynx [3]. The ibSLN controls sensory perception. Damage to this may result in loss of the laryngeal cough reflex, resulting in aspiration pneumonia. A previous study reported the efficacy of doublescope ESD (ds-ESD) for laryngeal cancers [4]. We believe that ds-ESD is effective in nerve preservation. Here, we report a case of successful nerve-sparing ESD using the double-scope method. A 72-year-old man presented with a 25 mm type 0-IIa lesion of the right piriform sinus (▶Fig. 1 a), which was surgically treated under general anesthesia (▶Video 1). During treatment, an otolaryngologist elevated the larynx using a curved laryngoscope (Nagashima Medical Instruments Co., Ltd., Tokyo, Japan) to ensure an adequate working space. Chromoendoscopy with 0.75% Lugol’s solution clearly revealed the lesion (▶Fig. 1b), and marking dots were placed around the lesion using a DualKnife J (KD-655Q; Olympus, Tokyo, Japan). Cutting and dissection were performed using a transoral endoscope (GIF-H290T; Olympus). A saline solution was injected into the subepithelium. After the mucosa was cut and the subepithelial layer was dissected to a length E-Videos