Emanuele La Corte1,2, Philipp R Aldana3. 1. Division of Pediatric Neurosurgery, University of Florida College of Medicine Jacksonville and Wolfson Children's Hospital, Jacksonville, FL, USA. 2. Department of Health Sciences, University of Milan and Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy. 3. Division of Pediatric Neurosurgery, University of Florida College of Medicine Jacksonville and Wolfson Children's Hospital, Jacksonville, FL, USA. philipp.aldana@jax.ufl.edu.
Abstract
BACKGROUND: Recent advances in endoscopic techniques have allowed minimally invasive approaches to the cranio-vertebral junction (CVJ) through the oropharynx (ETA) in addition to the transnasal approach (EEA). These minimally invasive endoscopic techniques allow for increased surgical exposure using no visible incisions, with a potential less morbidity. The ability to know preoperatively the limit of the ETA is vital for the surgical planning in order to better address CVJ pathology. The aim of the present study is to determine the anatomical limits of endoscopic dissection of the skull base and upper cervical spine through the transoral corridor and the superior limit reached by adopting this approach. METHODS: Six fresh-frozen adult cadaver heads were dissected adopting ETA preserving the hard and soft palate. The most superior extent of the exposure was dissected. Post-operative CT scans were performed to confirm the superior extent. RESULTS: The superior most limit of dissection corresponded to the sphenoid-occipital junction, where the basilar portion of the occipital bone joins with the sphenoid bone's body. This ranged from 12.7 to 18.9 mm above the line of the hard palate. This was achieved without having to transgress any of the palatine structures. CONCLUSIONS: The sphenoid-occipital junction represents the rostral limit of endoscopic transoral approach to the lower skull base and CVJ area. This approach is limited superiorly by the orientation of the hard palate and mouth aperture and lower dentition due to the linear nature of the endoscope. Using the endoscope for this approach can allow for a more superior exposure than the traditional open transoral approach.
BACKGROUND: Recent advances in endoscopic techniques have allowed minimally invasive approaches to the cranio-vertebral junction (CVJ) through the oropharynx (ETA) in addition to the transnasal approach (EEA). These minimally invasive endoscopic techniques allow for increased surgical exposure using no visible incisions, with a potential less morbidity. The ability to know preoperatively the limit of the ETA is vital for the surgical planning in order to better address CVJ pathology. The aim of the present study is to determine the anatomical limits of endoscopic dissection of the skull base and upper cervical spine through the transoral corridor and the superior limit reached by adopting this approach. METHODS: Six fresh-frozen adult cadaver heads were dissected adopting ETA preserving the hard and soft palate. The most superior extent of the exposure was dissected. Post-operative CT scans were performed to confirm the superior extent. RESULTS: The superior most limit of dissection corresponded to the sphenoid-occipital junction, where the basilar portion of the occipital bone joins with the sphenoid bone's body. This ranged from 12.7 to 18.9 mm above the line of the hard palate. This was achieved without having to transgress any of the palatine structures. CONCLUSIONS: The sphenoid-occipital junction represents the rostral limit of endoscopic transoral approach to the lower skull base and CVJ area. This approach is limited superiorly by the orientation of the hard palate and mouth aperture and lower dentition due to the linear nature of the endoscope. Using the endoscope for this approach can allow for a more superior exposure than the traditional open transoral approach.
Authors: Emanuele La Corte; Morgan Broggi; Alberto Raggi; Silvia Schiavolin; Francesco Acerbi; Giovanni Danesi; Mariangela Farinotti; Giovanni Felisati; Alberto Maccari; Bianca Pollo; Marco Saini; Claudia Toppo; Francesca Valvo; Riccardo Ghidoni; Maria Grazia Bruzzone; Francesco DiMeco; Paolo Ferroli Journal: Acta Neurochir (Wien) Date: 2020-01-16 Impact factor: 2.216