Sex based morphometric variations of the Vidian canal and their surgical implications in endoscopic endonasal skull base surgery

Moultrie, GA

Introduction: The Vidian canal is a structure within the sphenoid bone that runs inferomedial to the foramen rotundum and superior to the pterygoid plates. Anteriorly, it opens into the pterygopalatine fossa and transmits the pterygoid nerve, artery, and vein from the region of the foramen lacerum. The pterygoid nerve is formed by the union of the greater and deep petrosal nerves and contributes to autonomic and secretomotor innervation of the nasal cavity, paranasal sinuses, pharyngeal mucosa, and lacrimal gland. Because of its relationship to critical neurovascular structures, the Vidian canal serves as an important landmark in endoscopic endonasal skull base surgery. It is used to identify the anterior genu of the petrous internal carotid artery and guide transpterygoid approaches to structures such as the foramen lacerum. Previous morphometric studies have described variations in Vidian canal anatomy, including differences in canal length, angulation, sphenoid sinus pneumatization, and bony dehiscence. Some studies suggest these variations may be sex based; however, the consistency and surgical implications of sexual dimorphism remain unclear. This scoping review synthesizes literature on sex based morphometric differences of the Vidian canal and their relevance in endoscopic skull base surgery.

Methods: This scoping review followed a structured literature search approach consistent with PRISMA guidelines. Studies involving human subjects that evaluated the Vidian canal using CT, cone beam CT (CBCT), or cadaveric morphometric analysis were included. Eligible studies were required to report both male and female subjects or provide sex specific morphometric data and discuss the surgical relevance of Vidian canal measurements. Case reports, non-human studies, embryologic studies, and pediatric populations were excluded. A systematic search of PubMed, Scopus, and Embase databases was conducted.

Results: Fifteen studies met inclusion criteria and represented populations from China, Turkey, India, Kenya, Brazil, Iran, Libya, Japan, and the United States. The studies utilized CT imaging, CBCT, and cadaveric validation. Sample sizes ranged from 44 to 400 subjects. Vidian canal length was the most frequently reported morphometric parameter, ranging from approximately 12–18 mm. Several studies reported slightly longer canals in males, though statistical significance was inconsistent across studies. Canal diameter and angulation were reported less frequently; however, greater canal angulation was associated with increased surgical complexity during Vidian neurectomy. Many studies classified the canal according to its relationship with the sphenoid sinus (Type I–III), with Type II configurations most reported. Increased sphenoid sinus pneumatization was associated with Type II and Type III canals and occasional bony dehiscence. Across studies, the Vidian canal consistently served as a landmark for identifying the anterior genu of the petrous internal carotid artery during transpterygoid approaches.

Discussion: The Vidian canal plays a critical role in endoscopic skull base surgery, particularly during Vidian neurectomy and transpterygoid approaches. Although several studies suggest sex related differences in canal length and spatial relationships, findings remain inconsistent. Understanding morphometric variation may improve surgical orientation and help minimize vascular injury during skull base procedures. Future research using standardized morphometric measurements and correlation with surgical outcomes may clarify the clinical significance of sex based anatomical variation.