Abstract
Objectives Nasal endoscopic approaches to the sphenoid sinus are challenging. Variations in
septation, shape, and dimensions have a critical impact on surgical planning of the
skull base. Previous anatomical studies have small numbers or a limited description
of this complex structure. The present study is a radiographic analysis of the septation
and dimensions of the sphenoid sinus.
Design and Methods High-resolution surgical-guidance computed tomography images of the sinuses from
90 patients at a tertiary care medical center between 2002 and 2007 were studied.
Multiple anatomical measurements from axial and sagittal images were obtained and
analyzed with imaging and statistical software.
Results Of the 90 patients studied, 9% had presellar, 37% sellar, and 54% postsellar pneumatization.
In 34%, the posterior extent of the intersinus septum involved the bony covering of
the carotid artery. The average presellar width of the sinus was 1.3 cm, the average
midline presellar depth was 1.4 cm, and the average infrasellar midline depth was
2.6 cm.
Conclusions Approaching the skull base through the sphenoid sinus requires a tailored process
based on anatomy. Septal involvement of the carotid artery occurs frequently. Pneumatization
patterns are potentially disorienting, and awareness of the sinus's posterior and
lateral extensions is critical.
Keywords
endoscopic surgery - skull base - sphenoid
