Endoscopic Anatomy of the Palatovaginal Canal (Palatosphenoidal Canal): A Landmark for Dissection of the Vidian Nerve during Endonasal Transpterygoid Approaches

Introduction: The palatovaginal (PV) canal was classically described as a bony tunnel formed by the sphenoid process of the palatine bone and the vaginal process of the sphenoid bone, and it connects the pterygopalatine fossa with the nasopharynx. It transmits a pharyngeal branch of the internal maxillary artery. The canal is located medial to the vidian canal.

Aim: The purposes of this study are to describe and illustrate the endoscopic anatomy of the canal and artery, and to show the importance of these structures for the dissection of the vidian nerve and transposition of pterygopalatine fossa structures. The study also demonstrates that the traditionally known palatovaginal canal is a misnomer, and should be renamed “palatosphenoidal (PS) canal.”

Methods: Four fresh cadaveric heads were used in this study. Both sides were dissected in each specimen. A complete exposure of the PS canal and pharyngeal branch artery was performed before dissection of the vidian nerve and pterygopalatine fossa contents.

Results: The bony thickness of the sphenoid process of the palatine bone that covers the anterior aspect of the PS canal was quite variable. The canal has an orientation from lateral to medial and from superior to inferior.

Conclusions: Human cadaveric dissections demonstrated the important relationships of the palatovaginal (palatosphenoidal) canal with the pterygopalatine fossa and vidian canal and their relevance as surgical landmarks in endoscopic endonasal approaches.