The periepiglottic space: topographic relations and histological organisation.

Important aspects of histological organisation and topographic relations of the pre-epiglottic space are not fully understood. This region was therefore reinvestigated in plastinated serial sections of 19 human adult specimens. The cranial part of the pre-epiglottic space is homogenously filled with adipose tissue and extends around the epiglottis in a horseshoe fashion. Therefore, the term periepiglottic space (PES) is a more accurate description of this region. The cranial border of the PES is constituted by the hyoepiglottic membrane, which extends between the epiglottis and the tongue, and the hyoepiglottic ligament. The ligament consists of a cranial fibre layer anchored within the lingual muscles, and a caudal layer attached to the hyoid bone. Anterior to the lingual surface of the epiglottis, both fibre layers become apposed to form a dense collagenous mass, which may stabilise the epiglottis during deglutition. Contractions of the infrahyoid muscles will be transmitted to the thyrohyoid membrane anterior to the PES by numerous collagenous septa which originate from the membrane and radiate into the muscles. In contrast, the pre-epiglottic adipose tissue is not connected to the thyrohyoid membrane. The caudal part of the PES is subdivided by two paramedian sagittal collagenous septa. They include a medial compartment bordered by the epiglottis posteriorly and the thyroepiglottic ligament inferiorly. The two lateral subdivisions of the PES extend between the glands of the vestibular folds and towards the aryepiglottic folds, but a distinct confining collagenous layer is absent there. Posterolaterally, the PES is separated from the paraglottic space by the thyroarytenoid muscle and by a cranial extension of the fibrous sheet of the muscle. This collagenous tissue is often split into several layers and displays gaps which may facilitate the spread of malignancies.