Intraoperative navigation during atresiaplasty for congenital aural atresia

The purpose of this study was to evaluate the feasibility of intraoperative navigation (ION) using adhesive fiducials and high-resolution computed tomography (HRCT) of the temporal bone in pediatric patients undergoing atresiaplasty for congenital aural atresia (CAA).

From June 2018 to August 2019, a retrospective review was performed on pediatric patients with unilateral or bilateral CAA who underwent atresiaplasty with or without concurrent bone anchored implant (BAI) placement. Single stage atresiaplasty was performed at a tertiary referral center with ION linked to image-guidance compatible HRCT non-contrast temporal bone images. Up to six adhesive fiducials were placed for navigation. Patient demographics were collected including Schuknecht classification type and Jahrsdoerfer score. Main outcome measures included the number of useable adhesive fiducials for navigation, navigation system registration accuracy, operative time, intraoperative complications, and postoperative outcomes including facial nerve function, surgical site infection rate, restenosis rate, and audiometric data.

Five patients (3 male, 1 AU atresia, 2 AS atresia, all Schuknecht type C) with an average age of 9.2 years (range 6.8-11.8 years) underwent single sided atresiaplasty with ION. Two patients underwent concurrent BAI placement. Average Jahrsdoerfer score was 8.6 (range 7-10). Preoperative audiogram demonstrated a mean air-bone gap (ABG) of 45 dB (range 35-54 dB). The navigation system registration accuracy ranged from 0.08 to 1.80 mm (mean 1.00 mm). Mean operative time was 268 min (range 217-307 min). There were no intraoperative complications. At an average follow up of 7.2 months (range 2-15 months), postoperative facial nerve function was normal in all patients and no patients developed postoperative stenosis or surgical site infections. Four patients underwent postoperative audiogram at an average of 4 months after surgery (range 2-5 months) and all demonstrated an ABG of less than 30 dB (mean 20 dB, range 15-26 dB) with an average improvement in ABG of 23 dB (range 11-39 dB). The one patient who did not undergo postoperative pure tone audiometry underwent AzBio speech perception testing and demonstrated an improvement from 81% to 89%.

The use of ION in otologic surgery is uncommon. Inherent aberrant temporal bone anatomy in CAA makes this a unique population to study the value of this technology. The use of adhesive fiducials is feasible, with navigation registration accuracy and surgical outcomes comparable to those in the literature. More data is necessary regarding the impact of ION on long-term surgical and audiometric outcomes.