J Neurol Surg B Skull Base 2018; 79(02): 189-192
DOI: 10.1055/s-0037-1604405
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Compartmental Endoscopic Surgical Anatomy of the Inferior Intraconal Orbital Space

Alice Z. Maxfield
1   Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
2   Division of Otolaryngology, Brigham and Women's Hospital, Boston, Massachusetts
,
Christopher D. Brook
3   Department of Otolaryngology, Boston University School of Medicine, Boston, Massachusetts
,
Marcel M. Miyake
4   Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
5   Department of Otolaryngology, Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo, Sao Paulo, Brazil
,
Benjamin S. Bleier
1   Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
4   Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
› Author Affiliations
Further Information

Publication History

22 February 2017

10 June 2017

Publication Date:
04 September 2017 (online)

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Abstract

Objectives This study aims to define the endoscopic anatomy of inferior intraconal space, in terms of its neurovascular structures and relationship to fixed anatomic landmarks.

Design A cadaveric anatomical study was conducted.

Setting This study was conducted at an academic cranial base center.

Participants Cadaveric subjects have been investigated.

Main Outcome Measures After dissection of the inferior intraconal space, the number and position of ophthalmic artery (OA) and oculomotor nerve (OMN) branches to the inferior rectus muscle (IRM) were quantified relative to the fixed landmark of the posterior maxillary wall. The point where the OMN branch to the inferior oblique muscle (IOM) crossed the lateral IRM margin was quantified.

Results A total of 18 OA branches were identified with a mean ± standard deviation of 2.6 ± 0.53 branches. The mean distance of the OA branch insertion from the posterior maxillary wall was 7.11 ± 5.65 mm. The average number of OMN branches to the IRM was 1.63 ± 0.74 with a mean insertion distance of 1.88 ± 1.89 mm. The OMN branch to the IOM crossed the lateral IRM margin 5.38 ± 5.42 mm from the posterior maxillary wall.

Conclusions This cadaveric study quantifies the variability of two critical neurovascular structures salient to endoscopic approaches to the inferior intraconal space, the OMN, and OA contributions to the IRM. Knowledge of the interrelationship between these structures is essential in safe technique for dissection.

Note

There was no financial support for this study.