Systematic review and meta-analysis of cochlear implantation in deaf patients with large vestibular aqueduct...

Abnormal inner ear anatomy increases the risk of cochlear implantation because only a certain number of neurons can input signals to the auditory cortex. Therefore, the effectiveness and safety of cochlear implantation for patients with large vestibular aqueduct deformity (LVAD) are controversial and we explored whether cochlear implantation can improve the hearing of patients with this defect.

Randomized controlled trials of cochlear implantation for the treatment of LVAD were retrieved from the CNKI, Baidu Academic, VIP Medical, Wanfang Data, PubMed, EBSCO, Medline, and Cochrane databases from the date of establishment of the database to July 20, 2021. Chinese and English search keywords included Large vestibular canal malformation, Deafness, large vestibular aqueduct, and Cochlear implants. We used RevMan 5.3 to evaluate the quality of the literature.

A total of 5 documents that met the inclusion criteria were tested for overall heterogeneity. For the heterogeneity test of categories of auditory performance, Chi-squared (Chi2) =4.00, degrees of freedom (df) =1, I2=75%>50%, and P=0.05. Overall analysis using a random-effects model showed no statistically considerable difference between the deformity group and the control group [Z=0.78, mean difference (MD) =-0.65, 95% confidence interval (CI): -2.29 to 0.98, P=0.43]. There was no substantial difference in postoperative hearing ability between LVAD patients and those with normal inner ear structure. Continuous variables were used to describe the speech intelligibility rate (SIR) in a total of 48 cases, including 24 cases in the deformity group and 24 cases in the control group. For the heterogeneity test of the whole population, Chi2 =1.75, df =1, I2=43%<50%, and P=0.19. Overall analysis using a fixed-effects model showed that the difference between the deformity group and the control group was statistically considerable (Z=3.09, MD =-1.03, 95% CI: -1.69 to -0.38, P=0.002).

The meta-analysis results confirmed that with postoperative rehabilitation for LVAD patients with cochlear implants the clinical efficacy is similar to that of deaf patients with normal inner ear structure, providing an important basis for hearing restoration.