A Novel Instrument for Endoscopic Ear Surgery with a Steerable Flexible Tip: A Cadaveric Temporal Bone Study

By June 7, 2019

Swarup, Arushri1,2; Chayaopas, Nichtima1,3; Andrysek, Jan2; James, Adrian1
1 Department of Otolaryngology – Head & Neck Surgery, Hospital for Sick Children, University of Toronto, Canada;
2 Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada;
3 Khon Kaen Ear, Hearing and Balance Research Group, Department of Otorhinolaryngology, Khon Kaen University, Thailand.

Currently, surgical instruments for trans-canal totally endoscopic ear surgery (TEES) are rigid and have limited ability to reach deeply into tympanic recesses when used alongside the endoscope through the ear canal. A needs analysis study of TEES surgeons concluded that an instrument with extended reach to access additional structures visible endoscopically would be valuable during TEES1. A prototype novel steerable instrument with a flexible tip (SFT) has been developed to provide suction-enabled accessibility during TEES and evaluated in cadaveric temporal bones.


Eight otolaryngologists (novice to advanced endoscopic ear experience).
Evaluation of a prototype SFT during TEES simulation in cadaveric temporal bones. Aspects of SFT performance were rated on a five-point Likert scale.

– Main Outcome Measures: 
Evaluation of performance of the SFT within three categories: tip functionality, handle ergonomics, ease of use.
– Results:  
The majority of surgeons rated the following SFT characteristics as good (4 or 5): appropriate tip size, accurate and responsive tip movement, comfortable grip, handling as expected, intuitive operation, and SFT did not block the endoscopic field of view. The following characteristics of the SFT were less favorably rated including: handle size, force to operate, potential hand fatigue, effort required for tip bending. Saline was aspirated effectively from the operative field using the SFT.

The prototype SFT instrument can be used during TEES alongside the endoscope in cadaveric simulation. It provides suction-enabled accessibility into anatomical recesses during TEES. Further development is required to improve handle ergonomics and tip functionality to enable tissue dissection with a steerable, suction-enabled dissector for TEES.