Lesions of the Petrous Apex

77 Pages·2015·1.47 MB·English

Lesions of the Petrous Apex
Resident Physician: Nikunj A. Rana, M.D.
Faculty Mentor/Discussant: Dayton Young, M.D.
The University of Texas Medical Branch – UTMB Health
Department of Otolaryngology
Grand Rounds Presentation
January 28, 2015
Series Editor: Francis B. Quinn, Jr., MD, FACS --Archivist: Melinda Stoner Quinn, MSICS
Outline
Anatomy
I.
Clinical Presentation
II.
Common Lesions
III.
Cholesterol Granulomas
IV.
Surgical Approaches
V.
Outcomes
VI.
References
VII.
Skull Base Tumors
IAC

Jugular Foramen

Mastiod/Middle ear

EAC

Petrous Apex

Axial CT Anatomy
Axial CT Anatomy
The petrous apex is the pyramidal, medial projection of
•
the petrous portion of the temporal bone.
The normal petrous apex is relatively simple in form with
•
only one principal variation: the degree of pneumatization.
That is, the apex may be variably pneumatized with
•
aerated connections to the middle ear or may contain
predominantly marrow fat.
80% adult mastoid aerated
•
30% adult petrous region aerated, 7% asymmetric
•
(Brackman)
Medial View
Medial View
The petrous apex is the pyramidal, medial projection of the
•
petrous portion of the temporal bone.
Can be anatomically described as a pyramid- shaped structure
•
that can be divided in a posterior and an anterior part by a line
passing in the coronal plane through the internal auditory canal
Chole, RA. “Petrous apicitis: surgical anatomy,” Annals of Otology, Rhinology and
•
Laryngology, vol.94, no.3, pp. 254–257,1985.
Axial CT Anatomy
Axial CT Anatomy
The petrous apex of the temporal bone is located
•
anteromedial to the inner ear within the angle created by
the greater wing of the sphenoid bone anteriorly and the
occipital bone posteriorly.
The anterior margin of the petrous apex forms the medial
•
posterior wall of the middle cranial fossa.
Superior View