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.”
Keywords Endoscopic Endonasal Approach - lens cleaning - endoscopic visualization - skull base
surgery
