Surgical importance of neurovascular relationships of paranasal sinus region

Abstract

Objective: Damage to the optic nerve and internal carotid artery is a serious complication of transsphenoidal surgery. The relationships of the sphenoid sinuses to the carotid artery and optic nerve were studied on computerized tomography and their clinical importance was discussed. Methods: 45 (90 sides) paranasal tomography images consisting of coronal, axial or both coronal and axial images were evaluated. Tomographic findings including bony septum extending to the optic canal or internal carotid artery and protrusions and dehiscences of the walls of the internal carotid artery and the optic nerve were investigated. The results were classified as "present" or "absent". Results: We detected 28 protrusions and 4 dehiscences of internal carotid artery and 31 protrusions and 7 dehiscences of the optic nerve. Bony septum to the internal carotid artery and optic nerve was observed in 25 and 18 cases respectively. Conclusion: Detailed preoperative analysis of the anatomy of the sphenoid sinus and its neurovascular boundaries is crucial in facilitating entry to the pituitary fossa and reducing intraoperative complications. Axial and coronal images, or axialcoronal investigation obtained by direct acquisition or by reconstructions are necessary to show the positions and variations of the optic nerve and carotid artery.