J Neurol Surg B Skull Base
DOI: 10.1055/s-0039-1696957
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Middle Cranial Fossa Approach: Anatomical Study on Skull Base Triangles as a Landmark for a Safe Anterior Petrosectomy

1  Neurosurgery, Department of Neurosciences (DINOGMI), Policlinico San Martino, University of Genoa, Genova, Italy
2  Neurosurgery, Hospital de la Santa Creu I Sant Pau, Autonomous University of Barcelona, Barcelona, Spain
,
Rosa Mirapeix-Lucas
3  Department of Anatomy and Embryology, School of Medicine, Autonomous University of Barcelona, Spain
,
Gianluigi Zona
1  Neurosurgery, Department of Neurosciences (DINOGMI), Policlinico San Martino, University of Genoa, Genova, Italy
,
Alessandro Prior
1  Neurosurgery, Department of Neurosciences (DINOGMI), Policlinico San Martino, University of Genoa, Genova, Italy
,
Carlos Asencio Cortes
2  Neurosurgery, Hospital de la Santa Creu I Sant Pau, Autonomous University of Barcelona, Barcelona, Spain
,
Fernando Muñoz Hernandez
2  Neurosurgery, Hospital de la Santa Creu I Sant Pau, Autonomous University of Barcelona, Barcelona, Spain
› Author Affiliations
Further Information

Publication History

23 February 2019

28 July 2019

Publication Date:
12 September 2019 (online)

Abstract

Objective The Kawase approach provides access to the petroclival and posterior cavernous sinus regions, cerebellopontine angle, and upper basilar artery territory. Nevertheless, it remains one of the most challenging approach for neurosurgeons, due to the considerable related morbidity and mortality. The goal of this study was to evaluate the relationship between anatomical landmarks and their possible variations, and to measure the extension of the Kawase space, to define the reliability of these landmarks while performing an anterior petrosectomy.

Design Using eight cadaveric specimens (15 sides), an anatomical dissections and extradural exposure of the Kawase area were performed.

Settings A two-step analysis of the distances between the mandibular branch of the trigeminal nerve (V3) and the structures at risk of iatrogenic damage was performed.

Main outcome measures We measured the distance between V3 and the basal turn of the cochlea, and between V3 and the internal acoustic canal (IAC), analyzing the limits of bone resection without causing hearing damage.

Results We analyzed eight cadaveric (15 sides) formalin-fixed heads injected with colored silicone: four males and four females of Caucasian race (mean age: 73.83 years). We found a mean distance of 10.46 ± 1.13 mm between the great superficial petrous nerve (GSPN) intersection with V3 and the basal turn of the cochlea, and of 11.92 ± 1.71 mm between the origin point of V3 from the Gasserian ganglion and the fundus of the IAC.

Conclusion The knowledge of the safe distance between the most applicable anatomic landmarks and the hearing structures is a practical and useful method to perform this approach reducing related comorbidity.