Radiological Analysis of the Facial Recess: Impact on Posterior Tympanotomy Difficulty During Pediatric Cochlear Implantation.

OBJECTIVES

We analyzed several radiological features of the facial recess to correlate them with the intraoperative findings to highlight the most reliable predictors of posterior tympanotomy difficulty.

STUDY

DESIGN

Retrospective observational cohort study.

SETTING

Multicenter study at tertiary referral institutions.

METHODS

We included 184 pediatric patients who underwent cochlear implantation through the posterior tympanotomy approach. The correlation was attempted between 8 radiological features in the preoperative high-resolution computed tomography scan and intraoperative surgical difficulty.

RESULTS

Posterior tympanotomy was straightforward in 136 (73.9%) patients. In contrast, it was challenging in 48 (26.1%) patients. The facial recess was aerated in 74.5% of patients. The mean (SD) posterior tympanotomy depth was 3.98 (0.867) mm. The mean (SD) chorda-facial angle was 27.67° (3.406°). The mean (SD) chorda-facial to stylomastoid length was 3.898 (0.6304) mm. The mean (SD) facial nerve second genu angle was 94.54° (6.631)°. Deep-unaerated facial recess wall was associated with the most difficulty. There was a statistically significant difference in the unchallenging and challenging posterior tympanotomy groups regarding the surgical duration (P < .0001).

CONCLUSIONS

According to this analytic study, the chorda-facial angle, the facial recess aeration, and the chorda-facial to stylomastoid length were respectively the strongest preoperative radiological predictors of the surgical difficulty of posterior tympanotomy during cochlear implantation. Chorda-facial angle <25.5° was associated with difficult posterior tympanotomy. The oblique parasagittal cut was essential for the radiological analysis of the facial recess.