OTOPLAN in Cochlear Implantation for Far-advanced Otosclerosis

To evaluate OTOPLAN software in the surgical planning of far-advanced otosclerosis (FAO) candidates to cochlear implant (CI) were considered. We aimed to preliminarily investigate if this software could influence the electrode length choice, or predict surgical difficulties.

We reviewed the outcome of five consecutive FAO patients that underwent unilateral CI. OTOPLAN was used to evaluate preoperative computed tomography imaging. A comparison was made with historical data (eight FAO patients).

The mean cochlear duct length estimated by OTOPLAN was 32.4 mm. Evaluating OTOPLAN reconstructed images, we ruled out cochlear lumen fibrosis/ossification in three FAO patients and the longest electrodes according to cochlear dimensions were preferred. We disclosed fibrosis in the middle and apical turns of two patients. These findings allowed us to change surgical plans, choosing a shorter electrode (24 and 28 mm instead of 31 mm) to avoid incomplete insertion due to cochlear fibrosis. OTOPLAN reconstructed images identified preoperatively the two patients with round window niche ossification that required additional drilling during surgery. In the present series, we experienced no incomplete insertion. In two cases out of eight historical FAO patients, array insertion (24 mm) was incomplete. One years after unilateral CI, the mean speech reception threshold and disyllabic word recognition score of the five considered FAO patients were 36 dB and 94%, respectively (39 dB and 84% for the eight historical patients). There was no facial nerve stimulation or any other complication during the 1-year follow-up.

According to our preliminary results, OTOPLAN was useful for the appropriate choice of array length.