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J Neurol Surg B Skull Base 2025; 86(06): 640-651
DOI: 10.1055/a-2461-5608
Original Article

Surgical Anatomy of the Retrosigmoid Approach with Endoscopic-Assisted Reverse Anterior Petrosectomy: Optimizing Meckel's Cave Access from the Posterior Fossa

Authors

  • Alessandro De Bonis

    1   Mayo Clinic Rhoton Neurosurgery and Otolaryngology Surgical Anatomy Program, SW, Rochester, Minnesota, United States
    2   Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, United States
    3   Department of Neurosurgery and Gamma Knife Radiosurgery, San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy

  • Fabio Torregrossa

    1   Mayo Clinic Rhoton Neurosurgery and Otolaryngology Surgical Anatomy Program, SW, Rochester, Minnesota, United States
    2   Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, United States
    4   Neurosurgical Unit, Department of Biomedicine, Neurosciences and Advanced Diagnostics (BiND), University of Palermo, Palermo, Italy

  • Danielle D. Dang 

    1   Mayo Clinic Rhoton Neurosurgery and Otolaryngology Surgical Anatomy Program, SW, Rochester, Minnesota, United States
    5   Department of Neurosurgery, Inova Fairfax Medical Campus, Falls Church, Virginia, United States

  • Luciano César P. C. Leonel

    1   Mayo Clinic Rhoton Neurosurgery and Otolaryngology Surgical Anatomy Program, SW, Rochester, Minnesota, United States

  • Pietro Mortini

    3   Department of Neurosurgery and Gamma Knife Radiosurgery, San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy

  • Michael Link

    1   Mayo Clinic Rhoton Neurosurgery and Otolaryngology Surgical Anatomy Program, SW, Rochester, Minnesota, United States
    2   Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, United States
    6   Department of Otolaryngology/Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, United States

  • Driscoll Colin

    6   Department of Otolaryngology/Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, United States

  • Maria Peris-Celda

    1   Mayo Clinic Rhoton Neurosurgery and Otolaryngology Surgical Anatomy Program, SW, Rochester, Minnesota, United States
    2   Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, United States
    6   Department of Otolaryngology/Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, United States

Funding This study was funded by the Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, the Joseph and Barbara Ashkins Endowed Professorship in Surgery and the Radiology Department, Mayo Clinic, Rochester, Minnesota, and the Charles B. and Ann L. Johnson Endowed Professorship in Neurosurgery, Mayo Clinic, Rochester, Minnesota.
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Abstract

Objectives

We investigated the extent of access to Meckel's cave (MC) and the middle cranial fossa (MCF) protecting the internal carotid artery (ICA) using the retrosigmoid approach with endoscopic-assisted reverse anterior petrosectomy (EA-RAP).

Methods

Five specimens were dissected using the limited and extended EA-RAP. Based on the bone removal of the internal acoustic meatus (IAM) and subarcuate fossa, exposure of the MC and ICA were statistically compared.

Results

The limited and extended EA-RAP allowed access to the medial and anterior MC (4 mm posterior to the first genu of the cavernous ICA, and 20 mm posterior to foramen rotundum [FR]). The access to the lateral MC varied with distance of 12 and 8 mm medial to the foramen ovale for the limited and extended EA-RAP, respectively.

In the extended EA-RAP, the exposure of the ICA was gained by drilling with the 0-degree endoscope (3 mm) versus 45-degree endoscope (9 mm). The working distances from the midpoint of the IAM to the most medial point of the exposed ICA was 24 mm. The most lateral point of the exposed ICA varied between 0- and 45-degree endoscopes with a distance of 21 and 13 mm, respectively.

Conclusion

A coronal plane from the posterior genu of the cavernous ICA and a sagittal plane to the common crus of the semicircular canals can define the area of MCF accessed by the EA-RAP. Drilling of the temporal bone should be carefully customized according to the patient and can be aided by endoscopic assistance for direct visualization to minimize the risk of injuries to ICA.

Keywords

RAP - EA-RAP - retrosigmoid intradural suprameatal approach - RISA - Meckel's cave - petrous internal carotid artery - retrosigmoid - reverse anterior petrosectomy - suprameatal tubercle

Authors' Contributions

A.D.B. contributed to conceptualization, methodology, formal analysis, investigation, drafting, and review and editing. M.P.C. contributed to conceptualization, methodology, review and editing, funding acquisition, and supervision. L.C.P.C.L. contributed to methodology and formal analysis. D.D.D. contributed to drafting. F.T. and P.M. contributed to review and editing.


Research Involving Human Participants and/or Animals

Institutional review board and biospecimens committee approval from the Mayo Clinic was obtained for this study.


Informed Consent

Informed consent for participation and publication in research was not required for this study.




Publication History

Received: 22 October 2024

Accepted: 04 November 2024

Article published online:
03 December 2024

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