Surgical anatomy of the sphenoid sinus on the CT using multiplanar reconstruction technique.

OBJECTIVE To clarify the three-dimensional anatomical features of the sphenoid sinus and its surrounding structures as are relevant to performing an endoscopic sphenoidotomy. METHODS Various dimensions of 224 CT images of the sphenoid sinus and surrounding structures from 122 Japanese adult patients were measured using the multiplanar reconstruction technique. RESULTS The mean distance from the nasal sill to the sphenoid ostium was nearly 66 mm, and that from the sphenoid ostium to the posterior wall of the sphenoid sinus was nearly 14 mm. The angles from the sphenoid ostium to both the carotid artery and the optic canal varied among the patients. The sphenoid ostium was located at almost the vertical midpoint of the anterior wall of the sphenoid sinus. CONCLUSION The present study provides anatomical information about the sphenoid sinus and surrounding structures that is essential for avoiding complications in performing an endoscopic sphenoidotomy.