Importance of an unclear fascial layer, stylopharyngeal fascia: an anatomical study

Abstract

Objectives: The stylopharyngeal fascia is an important anatomical structure; however, its exact location and relationship with other neighboring structures have not been clearly demonstrated. Therefore, our aim was to reveal the stylopharyngeal fascia to demonstrate its course and neurovascular relationship in the parapharyngeal space. Methods: Ten fresh frozen cadaveric necks were dissected through a transparotideal and transcervical approach extending to the parapharyngeal region. All the neurovascular structures and muscles were preserved to demonstrate the stylopharyngeal fascia. Results: The stylopharyngeal fascia was mostly found on the lateral aspect of the internal carotid artery and could be found by advancing into the plane between the posterior belly of the digastric and stylohyoid muscles at the parapharyngeal space borders. The stylopharyngeal fascia covered not only the parapharyngeal segment of the internal carotid artery but also the cranial nerves X–XII at the parapharyngeal space. The cranial nerve IX coursed laterally to this fascial structure, posterior to the stylopharyngeus muscle in the parapharyngeal space. Conclusion: Although the stylopharyngeal fascia was previously shown to be related to other neurovascular structures, its anatomical course and histology remain unclear. Moreover, the stylopharyngeal fascia was defined using different nomenclatures in different studies. In this study, the stylopharyngeal fascia was shown to be an important anatomical landmark for dissection at the border of the parapharyngeal space. Further studies investigating its histological structure and defining its proper nomenclature are required. Therefore, we propose the term “parapharyngeal fascia”.