Infrahyoid spread of deep neck abscess: anatomical consideration

The aim of this study was to determine the pathway of infrahyoid extension of the oropharyngeal abscess considering the anatomy of the fascial spaces by cross-sectional imaging. CT scans and MR images were retrospectively reviewed in ten patients with known infrahyoid extension of oropharyngeal abscesses (eight with acute tonsillitis, two with acute phlegmonous oropharyngitis). In seven of eight patients tonsillar abscesses descended along the deep cervical fascia converging on the hyoid bone and further accumulated in the anterior cervical space through which extension to the mediastinum took place in four patients. In seven patients the abscesses involved the retropharyngeal space at the infrahyoid neck. In two of these seven patients the abscesses directly extended down into the upper mediastinum through the retropharyngeal space. In one patients of the seven mediastinal spread of an abscess occurred through the posterior cervical space, not through the retropharyngeal space. Cross-sectional imaging is valuable in the evaluation of deep neck abscesses and the pathway of spread. The anterior cervical space in the infrahyoid neck is important for mediastinal extension of pharyngeal abscesses.