Does cochlear implant electrode array design affect audiologic outcomes? A systematic review and meta-analysis.

Background: There is conflicting literature regarding whether cochlear implants (CI) electrode array (EA) selection impacts audiologic outcomes.

Objective: To compare outcomes for the two EA designs, precurved and straight.

Methods: A systematic search of CINAHL, Cochrane Library, PubMed, and SCOPUS was conducted according to PRISMA guidelines. Included studies reported word recognition scores, sentence recognition scores in quiet or noise, or hearing preservation (HP) rates for patients with post-lingual hearing loss who underwent CI with either EA type. Primary outcome measures included mean difference (baseline vs. post-surgery) and proportions (%) with 95% confidence intervals (CI).

Results: Of 4134 unique abstracts screened, 92 studies (N = 5365 patients, 5658 ears) were included. Mean improvement of overall word recognition scores for patients with precurved EAs (46.5%, 95% CI: 43.13-49.88%) was significantly (p = 0.0009) superior to that of patients with straight EAs (36.33%; 95% CI, 31.4-41.27%). There was no significant difference between mean improvement of Azbio Quiet scores, mean improvement of overall sentences in noise scores, or HP or pure-tone averages between patients with precurved EAs and those with straight EAs.

Conclusions: Precurved EAs were superior in mean word recognition score improvement, but there was no superior EA design regarding sentence recognition or hearing preservation.