Sphenoid Sinus and Related Neurovascular Structures-Anatomical Relations and Variations on Radiology-A Retrospective Study.

Abstract

The aim of this study was to evaluate sphenoid sinus pneumatisation and its anatomical relation with adjacent neurovascular structures in Indian population. We performed a retrospective cross-sectional study, in which the pattern of sphenoid sinus pneumatization was studied on high-resolution computed tomography scans (n = 400), and association of the optic nerve, vidian canal and foramen rotundum along with related morphometric measurements were studied. Out of 400 CT scans, 60.5% were males. Majority had sellar type of pneumatization (89.5%) and single intersinus septum (68%). The most common configuration of relation of optic nerve canal was DeLano type 2 (34.75%). Vidian canal (VC) and Foramen rotundum (FR) were found dehiscent in 40.5% and 6.38% respectively. Average distance of FR from midline on right and left side was 16.3 ± 2.19mm and 16.7 ± 2.23mm respectively. Average distance of VC from midline on right and left side was 12.4 ± 5.84mm and 12.4 ± 4.18mm respectively. Average right FR to VC distance was 4.17 ± 2.16mm and left FR to VC was 4.44 ± 2.20mm. Anatomical variations of the sphenoid sinus are well known. In the present study, we have tried to highlight the importance of knowledge of various anatomical variations in relations to sphenoid sinus as they are critical in planning of surgery. Pre-operative radiological study and correlation is inevitable to assess type and extent of sinus pneumatisation, bony dehiscence and septal terminations to avoid injury to vital structures.