Techniques and challenges of the expanded endoscopic endonasal access to the ventrolateral skull base during the “far-medial” and “extreme medial” approaches
Expanding the ventrolateral skull base corridor from the midline of lower clivus to the petroclival fissure is a challenging endonasal surgical task. Resection of lytic lesions like chondrosarcoma can cause cranial nerve morbidities and injury of ICA, necessitating accurate knowledge of correlative endoscopic anatomy with stereotactic landmarks.
We describe an extended endoscopic endonasal approach (EEA) for a right petroclival chondrosarcoma with the demonstration of ipsilateral surgical landmarks with contralateral normal correlates, using a stepwise comparative image-guided cadaveric dissection study.
EEA for lytic lesions like chondrosarcomas needs to address brain shift and displacement of ICA, posing a chance for cranial nerve morbidities and ICA injury. Meticulous utilization of intraoperative stereotactic landmarks can help avoid and mitigate surgical complications.
KeywordsFar-medial Extreme medial Expanded endonasal Transclival approach Lower clivus Skull base Sublacerum corridor Endoscopic landmarks
Expanded endoscopic endonasal approaches
Endoscopic far-medial approach
Lateral pharyngeal tubercle
Image guidance system
Endoscope-integrated indocyanine green fluorescence
Internal carotid artery
Expanded endonasal approach
Somato-sensory evoked potential
We thank Ricardo L. Carrau, MD, for his invaluable guidance and intellectual contribution during this project.
Compliance with ethical standards
Conflict of interest
This study was performed at ALT-VISION at The Ohio State University. This laboratory receives educational support from the following companies: Carl Zeiss Microscopy, Intuitive Surgical Corp., KLS Martin Corp., Karl Storz Endoscopy, Leica Microsystems, Medtronic Corp., Stryker Corp., and Vycor Medical. Dr. Prevedello is a consultant for Stryker Corp., Medtronic Corp., and Integra; he has received an honorarium from Mizuho and royalties from KLS- Martin. N. London holds stock in Navigen Pharmaceuticals currently of no value and was a consultant for Cooltech Inc., both of which are unrelated to this manuscript.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the Ohio State University Wexner Medical Center institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
- 1.Benet A, Prevedello DM, Carrau RL, Rincon-Torroella J, Fernandez-Miranda JC, Prats-Galino A, Kassam AB (2014) Comparative analysis of the transcranial “far lateral” and endoscopic endonasal “far medial” approaches: surgical anatomy and clinical illustration. World Neurosurg 81(2):385–396CrossRefGoogle Scholar
- 3.Little RE, Taylor RJ, Miller JD, Ambrose EC, Matthew DMS, Adam GE (2014) Endoscopic endonasal transclival approaches : case series and outcomes for different clival regionsGoogle Scholar
- 5.Moussazadeh N, Kulwin C, Anand VK, Ting JY, Gamss C, Iorgulescu JB, Tsiouris AJ, Cohen-gadol AA, Schwartz TH (2015) Endoscopic endonasal resection of skull base chondrosarcomas: technique and early results. 122(April):735–742Google Scholar
- 7.Ruiz-valdepeñas EC (2018) How I do it : endoscopic endonasal approach to the inferior third of the clivus. 741–745Google Scholar
- 10.Zwagerman NT, Wang EW, Shin SS, Chang Y-F, Fernandez-Miranda JC, Snyderman CH, Gardner PA (2018) Does lumbar drainage reduce postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery? A prospective, randomized controlled trial. J Neurosurg:1–7Google Scholar