Eur J Anat, 24 (2): 99-109 (2020)

Classification, neurovascularrelations and ostia of the sphenoid air sinus: a cadaveric study

Ntombifuthi P. Ngubane, Lelika Lazarus, Carmen O. Rennie, Kapil S. Satyapal

Department of Clinical Anatomy, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal Westville Campus, Durban 4000, South Africa

ABSTRACT The sphenoid air sinus is located deep at the base of the skull and is intimately related to deli-cate neurovascular structures. The purpose of this study was to describe the variations of the sphe-noid sinus in relation to pneumatisation within the sphenoid bone, its ostium and the structures relat-ed to the walls of the sinus. Twenty-five cadaveric specimens were cut mid-sagittally and studied bi-laterally (n=50). The pre-sellar, sellar and post-sellar sphenoid sinus types were observed in 16%, 36% and 48% cases, respectively. The protrusion of the internal carotid artery (ICA) in relation to the sinus walls was observed in 70% cases, while bulges of the optic (ON), maxillary (MN) and Vidian (VN) nerves were observed in 56%, 32% and 22% cases, respectively. Protrusions of ICA, ON and VN were prevalent in post-sellar sinuses and the bulge of MN was prevalent in the sellar sinuses. The ICA had a longer course in sellar and post-sellar sphenoid sinuses. The sphenoid sinus osti-um shape was oval in 72.55% cases and round in 27.45% cases. The ostia were located superiorly on the anterior wall of the sinus in 34.69% cases and in the middle in 65.31% cases. Knowledge on the level of complexity and variability of the sphe-noid sinus plays a pivotal role in preparing for saferendoscopic trans-sphenoid surgical approaches.

Keywords: Sphenoid sinus â?? Paranasal sinus â?? Neurovascular relations â?? Pneumatisation â?? Endo-scopic endonasal trans-sphenoidal procedures