An Ovine Model for Exclusive Endoscopic Ear Surgery.

IMPORTANCE

With the international spread of exclusive transcanal endoscopic ear surgery, the need for a suitable and affordable surgical training model has grown during the past years.

OBJECTIVE

To develop and validate an ex vivo animal model for exclusive endoscopic ear surgery.

DESIGN, SETTING, AND ANIMAL MODELS: In an experimental study, we compared ovine and human middle ear anatomy in 4 specimens and assessed the lamb as a model for endoscopic ear surgery. After confirming its suitability, we developed a surgical training program for canaloplasty, myringoplasty, and ossiculoplasty. From March 1 to May 31, 2016, the ex vivo model was tested, assessing the time needed for dissection and complications. Each experience was subjectively validated on a scale from 1 (very poor) to 10 (excellent).

MAIN OUTCOMES AND MEASURES: Suitability of the lamb model for training in exclusive endoscopic ear surgery.

RESULTS

We assessed the suitability of our novel lamb model on 20 ovine middle ears. All interventions could be performed in a satisfactory manner. The mean (SD) time required to perform canaloplasty was 29.7 (13.2) minutes, for middle ear dissection was 7.7 (2.6) minutes, for myringoplasty was 7.7 (4.3) minutes, and for ossiculoplasty was 10.4 (2.7) minutes. The time required for canaloplasty and tympano-meatal flap elevation during dissection decreased from 46.4 minutes in the first 5 cases to 16.2 minutes in the last 5 cases, representing an absolute difference of 30.2 minutes (95% CI, 22.28-38.12). Subjective ratings revealed excellent values for tissue quality (8.9 points of 10), overall satisfaction (8.3 points), and the learning experience (8.8 points).

CONCLUSIONS AND RELEVANCE: The ovine model is suitable for endoscopic ear surgery. We describe a novel, exclusively endoscopic approach in an ex vivo animal model for middle ear surgery. The proposed surgical program leads the trainee step by step through the main otologic procedures and is able to enhance his or her surgical skills.