Abstract
Introduction The petrous apex poses a challenge for surgical intervention due to poor access.
As intraoperative image guidance and surgical instrumentation improve, newer endoscopic
approaches are increasingly favored. This study aims to provide normative data on
the anatomy of the lateral sphenoid sinus recess and petrous apex. These normative
data could assist in determining the efficacy of a transnasal transsphenoidal approach
to lesions of the anteroinferior petrous apex.
Methods This is a retrospective study investigating normative data on all maxillofacial computed
tomography (CT) scans performed at a level I trauma center over a 6-month period.
All appropriate images had the pneumatization pattern of the petrous apex and lateral
recess of the sphenoid sinus reviewed by a single otologist and graded bilaterally.
These were then analyzed in SPSS; Pearson correlation analyses and χ2 test were used.
Results A total of 481 patients were identified, yielding a total of 962 temporal bones and
sphenoid sinuses for analysis. Eighty-eight percent of sides analyzed had a nonpneumatized
lateral recess. The petrous apex was nonpneumatized in 54% of sides analyzed. There
was a correlation noted between the degree of pneumatization of the petrous apex and
pneumatization of the lateral recess of the sphenoid.
Conclusion This study is the first to provide normative data comparing pneumatization of the
petrous apex and sphenoid sinus. These data may support future work evaluating the
utility of an endonasal approach to the petrous apex.
Keywords
petrous apex - sphenoid sinus - skull base - pneumatization
