The inside-out surgical anatomy of the paraglottic space a video-guided endoscopic dissection.

Objectives: The paraglottic space is an essential anatomic compartment of the larynx. It is central to the spread of laryngeal cancer and to the choice of conservative laryngeal surgery and many phonosurgical procedures. Since its description, 60 years ago, the surgical anatomy of the paraglottic space was sparsely revisited. Amid the era of endoscopic and transoral microscopic functional surgery of the larynx, we provide here a long-awaited description of the inside-out anatomy of the paraglottic space. Methodology: Using an endoscope equipped with a 3D camera, we dissected 10 hemilarynges from 5 fresh frozen cadavers from the inside out. Before dissection, we labeled the vessels through injecting them with colored latex. We explored the paraglottic space emphasizing its shape, boundaries, and contents. We documented our findings through endoscopic photography and video recordings. Results: The paraglottic space is a spacious tetrahedral space located parallel not only to the glottic, but also to the subglottic and the supraglottic compartments of the laryngeal lumen. It has musculo-cartilaginous, musculo-fibrous, and mucosal boundaries. It is separated from the pyriform sinus only by mucosa. A cushion of fat surrounds its vascular and to a lesser extent its neural contents. Harbored intrinsic laryngeal muscles are endoscopically identifiable within the space, namely the thyroarytenoid, the lateral, and posterior cricoarytenoid muscles. Conclusion: The endoscopic description of the paraglottic space partly fills the knowledge gap on the laryngeal anatomy from the inside out. It opens the door for novel diagnostic methods and for ultraconservative functional laryngeal interventions under endoscopic control. Level of Evidence: N/A.