Mexican Sphenoid Sinus Radiological Anatomy: High Risk Anatomy for Endoscopic Endonasal Skull Base Surgery

Abstract

Background: We present a detailed description of the radiological anatomy of the sphenoid sinus and neurovascular structures that surround it from an endoscopic endonasal skull base surgical perspective and in an exclusively Mexican patient population. Methods: We performed a cross-sectional study of 500 patients form the Neurosurgery Patient Database at the Specialties Hospital of the 21st Century National Medical Center. Inclusion criteria were minimum age of 18 years old, availability of fine cut CT with skull base reconstruction, absence of skull base pathology, trauma, and radiological artifacts or distortion at the area of study. Results: These 500 patients have a sphenoid sinus with predominant sagittal post-sellar type and coronal pre-rotundum type pneumatization patterns, single intrasinus septae with predominant posterior insertion over the internal carotid arteries, intrasinus non visible carotid artery prominences, thinned carotid canal bony thickness, intrasinus non visible optic nerve prominences, and thinned optic canal bony thickness. Conclusion: Our study suggests that Mexican patients have a well pneumatized sphenoid sinus with few visible neurovascular landmarks and thin bone coverings over the internal carotid arteries and optic nerves. This may increase the risk for optic nerve or internal carotid artery injury during endonasal transsphenoidal surgery. We believe this information will be useful for effective preoperative planning and safe surgical execution during endoscopic endonasal skull base surgery in Mexican patients.