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Updated: Oct 20, 2025
Role of Diffusion MRI Tractography in Endoscopic Endonasal Skull Base Surgery
Published on: July 5, 2021
Utility of Nasal Access Guides in Endoscopic Endonasal Skull Base Surgery: Assessment of Use during Cadaveric
Nathalia Velasquez1, Omar H Ahmed1, Philippe Lavigne1
1Department of Otolaryngology-Head and Neck Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.
Abstract:
Background A nasal access guide (NAG) for endoscopic endonasal approaches (EEAs) to the skull-base has been developed and approved for clinical use but its utility has not been formally investigated. Objective The study aims to assess the effect of a NAG on endoscopic visualization during cadaveric dissection and to perform a workflow analysis with process-based performance measures in the operating room and their effect on clinical outcomes. Methods Skull-base course participants were observed during hands-on cadaveric dissection with and without NAG. Instances of endoscope withdrawal for lens cleaning and inadequate visualization due to lens soiling were tabulated. Participants completed a Likert-scale survey examining the NAG utility and provided an overall grading. Surgical workflow and process-based performance on patients undergoing EEA to the skull-base was analyzed. Passage of powered and dissecting instruments, removal of endoscopes for cleaning, and dislodgment or migration of the device were reviewed. Postoperative assessments included mucosal trauma and synechiae formation. Results Instances of endoscope soiling and manual cleaning were significantly reduced by 40% and 61% with the NAG during cadaveric dissection. The overall grading of the device was 2.75/3. Surgical workflow was observed in 35 patients. Average number of passes of endoscopes, instruments, and powered tools during a 10-minute observation period were 3,17, and 5 during the surgical approach, and 3, 18, and 1 during tumor dissection. Dislodgement of the device occurred in 25.7% and migration of the device in 2.8% of cases. Postoperative synechiae, exposed cartilage or septal perforation was not observed in follow up. Conclusion NAG can significantly reduce inadequate visualization during EEA to the skull-base and has the potential to reduce instances of nasal trauma. Participants assessed its overall utility as being "excellent."
