Objectives: (1) Describe the relations of the facial recess (FR) to the sinus
tympani (ST), posterior tympanic sinus (PTS), lateral tympanic sinus (LTS),
mastoid segment of the facial nerve (FN), and stapedius muscle (STM)
based on their otoendoscopic, surgical, and radiologic anatomy and in relation
to their development theories. (2) Evaluate the possible surgical approaches. Methods:
Fifty-five temporal bones were dissected, and the anatomic details
were studied utilizing an operating microscope and otoendoscopes of
different
angles. In addition, the recesses anatomy and relations were studied
in 200 temporal bones computed tomography scans.
Results:
The
retrotympanic recesses pneumatization could be classified as
axial
(FR) and sagittal (ST, PTS, and LTS). The 3 sagittal recesses showed
fixed
relations to each other, with ST and PTS medially (superiorly and inferiorly,
respectively) and LTS laterally. FR inlet located superolateral to the
other
sinuses while the recess itself extended laterally (44%) and posteriorly
(20%) to them and in relation to the FN and SM. When ST was extensively
pneumatized, it showed a direct relation with the FR extension posterior
to
the FN. Although it was possible to approach all 4 recesses endoscopically
via the transcanal route, it was necessary to approach FR and ST via
combined
transcanal and transmastoid approaches when they were extensively
pneumatized posteriorly and laterally.
Conclusions:
Relations
between the FR and the retrotympanic structures
are
significantly variable and influenced mainly by the type and extent of the
pneumatization.
Extensively or unusually pneumatized types need special
or combined approaches