Skull Base 2004; 14(1): 9-19
DOI: 10.1055/s-2004-821353
ORIGINAL ARTICLE

Copyright © 2004 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA

Surgical Approaches to the Petrous Apex: Distances and Relations with Cranial Morphology

Murilo S. Meneses1 , 2 , Ana Lucila Moreira1 , Kelly C. Bordignon2 , Ari A. Pedrozo2 , Ricardo Ramina2 , Jeziel G. Nikoski2
  • 1Department of Anatomy, Federal University of Paraná, Curitiba-PR, Brazil
  • 2Instituto de Neurologia de Curitiba, Curitiba-PR, Brazil
Further Information

Publication History

Publication Date:
04 June 2004 (online)

Zoom Image

Different pathologies may be located at the petrous apex. The primary surgical approaches used to remove such lesions are the pterional, subtemporal, presigmoid, and retrosigmoid. Each has advantages and disadvantages, and the distance to the petrous apex varies with the approach. Anatomical variations in cranial morphology may interfere with these distances. Dolichocephalic skulls have a longer anteroposterior axis than brachycephalic ones.

Three hundred computed tomographic scans and 65 dry human skulls were analyzed to determine if cranial morphology could indicate the shortest distance to the petrous apex. The distance between the external cortical table of the skull and the petrous apex in each surgical approach was measured. The lengths of the anteroposterior axis (L) and the widths of the lateral axis (W) were measured to determine the cranial index (W/L × 100).

This distance was longest in skulls with a high cranial index (brachycephalic) independent of the approach used. Statistical analysis showed that the distance to the previous apex was longest in the retrosigmoid approach and shortest in the pterional approach in all kinds of skulls. Brachycephalic skulls lose this ellipsoidal shape and the anterior laterolateral diameter is smaller than the posterior laterolateral diameter. Consequently, the distance from the cortical skull table to the petrous apex is shorter in brachycephalic skulls using all surgical approaches described in this article.