The Intersection Between the Oculomotor Nerve and the Internal Carotid Artery to Distinguish Extracavernous and Intracavernous Paraclinoid Aneurysms Using Anatomic Dissections-A New 3T Magnetic Resonance Imaging Protocol Confirmed by Three-Dimensionally Printed Biomodels

Authors

Hugo Leonardo Doria-Netto, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (Unifesp), São Paulo, São Paulo, Brazil; Division of Neurosurgery, Hospital Beneficência Portuguesa de São Paulo, São Paulo, Brazil.
Christiane Monteiro Campos, Division of Neuroradiology, Hospital Beneficência Portuguesa de São Paulo, São Paulo, Brazil.
Victor Hugo Marussi, Division of Neuroradiology, Hospital Beneficência Portuguesa de São Paulo, São Paulo, Brazil.
José Maria Campos-Filho, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (Unifesp), São Paulo, São Paulo, Brazil; Division of Neurosurgery, Hospital Beneficência Portuguesa de São Paulo, São Paulo, Brazil.
Jean Faber, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (Unifesp), São Paulo, São Paulo, Brazil.
Michael T. Lawton, Department of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.Follow
Feres E. Chaddad-Neto, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (Unifesp), São Paulo, São Paulo, Brazil; Division of Neurosurgery, Hospital Beneficência Portuguesa de São Paulo, São Paulo, Brazil. Electronic address: feres.chaddad@unifesp.br.

Document Type

Article

Abstract

OBJECTIVE: To evaluate the relationship between the oculomotor nerve (CNIII) and the internal carotid artery (ICA) as a new anatomic-radiologic landmark for distinguishing the exact location of a paraclinoid intracranial aneurysm (IA). METHODS: Microanatomic dissections were performed in 20 cavernous sinuses to evaluate the ICA paraclinoid region. Based on anatomic observations, a new magnetic resonance (MRI) protocol to classify paraclinoid aneurysms was proposed. MRI of 42 IAs from 34 patients was independently analyzed and classified as intracavernous, extracavernous, or transitional by 2 neuroradiologists. To validate the proposed MRI protocol, each IA was classified by a three-dimensionally (3D) printed biomodel and agreement with the radiologic classifications was evaluated. Of 42 IAs, 23 undergoing microsurgeries were also classified by direct visualization. RESULTS: We observed that the true cavernous sinus roof is defined by the carotid-oculomotor membrane, which has an intimate relationship with the intersection between the superior limit of the CNIII and the ICA. Based on this intersection, all 42 IAs were radiologically classified and agreement with the 3D printed biomodels was observed in 95% IAs. Concordance tests showed a statistically significant (P < 0.05) agreement between the classifications. All 23 IAs treated had the radiologic and 3D biomodel classification confirmed. CONCLUSIONS: The intersection between the ICA and the CNIII, which crosses it transversely in its entire diameter, is a reliable anatomic-radiologic landmark to correctly classify paraclinoid aneurysms. Through a new MRI protocol, it is possible to radiologically identify this intersection and to easily distinguish the intracavernous and extracavernous ICA paraclinoid aneurysms.

Medical Subject Headings

Humans; Carotid Artery, Internal (surgery); Oculomotor Nerve (diagnostic imaging); Intracranial Aneurysm (diagnostic imaging, surgery, pathology); Magnetic Resonance Imaging (methods); Carotid Artery Diseases (diagnostic imaging, surgery, pathology); Printing, Three-Dimensional

Publication Date

11-1-2022

Publication Title

World neurosurgery

E-ISSN

1878-8769

Volume

167

First Page

e475

Last Page

e506

PubMed ID

35970294

Digital Object Identifier (DOI)

10.1016/j.wneu.2022.08.030

Recommended Citation

Doria-Netto, Hugo Leonardo; Campos, Christiane Monteiro; Marussi, Victor Hugo; Campos-Filho, José Maria; Faber, Jean; Lawton, Michael T.; and Chaddad-Neto, Feres E., "The Intersection Between the Oculomotor Nerve and the Internal Carotid Artery to Distinguish Extracavernous and Intracavernous Paraclinoid Aneurysms Using Anatomic Dissections-A New 3T Magnetic Resonance Imaging Protocol Confirmed by Three-Dimensionally Printed Biomodels" (2022). Neurosurgery. 1843.
https://scholar.barrowneuro.org/neurosurgery/1843