Endoscopic classification of the external auditory canal for transcanal endoscopic ear surgery

Abstract

Objective: Evaluation of an endoscopic anatomic classification of the external auditory canal (EAC) for transcanal endoscopic ear surgery.

Materials and method: The EAC Canal Endoscopic Scale (CES) was initially defined according to total or partial EAC narrowing on 0° transcanal endoscopy. A retrospective study was then conducted between September 2013 and March 2015 in a series of consecutive patients fulfilling the study inclusion criteria.

Results: A total of 83% of 5000 patients (10000 ears) were classified as CES 0: i.e., total visualization of the tympanic membrane. Various kinds of EAC narrowing were described. Results were comparable between right and left ears.

Conclusions: 0° endoscopy provided total visualization of the tympanic membrane in most cases, thanks to its magnified lateral view. Preoperative CES classification allows use of angled endoscopes, curved instruments or drilling for canalplasty to be planned in the first step of transcanal endoscopic ear surgery.

Keywords: Anatomy; Classification; Ear; Endoscopy; External auditory canal.