Cerebrospinal fluid gusher in cochlear implant and its associated factors

The effect of cochlear implant insertion technique on post-operative neural response telemetry and impedance in paediatric patients

OBJECTIVE

This study aimed to compare neural response telemetry and impedance between the round window and cochleostomy approaches for cochlear implantation.

METHODS

In this case-control study, 64 patients aged less than 3.5 years underwent cochlear implantation via the round window or cochleostomy approach. Post-operative neural response telemetry and impedance were measured.

RESULTS

The impedance measurements at electrodes 1, 11 and 22 showed no significant differences between the two groups three months after implantation (p = 0.90, p = 0.08 and p = 0.37, respectively). Similar results were observed six months after implantation (p = 0.71, p = 0.65 and p = 0.70, respectively). There was no significant difference in neural response telemetry between the two groups after three months. The neural response telemetry of electrode 1 in the cochleostomy group (171.26 ± 19.81 μV) was significantly higher in comparison with that of electrode 1 in the round window group (161.97 ± 12.71 μV) after six months (p = 0.03). The neural response telemetry values for electrodes 11 and 22 did not show any significant difference after six months (p = 0.14 and p = 0.48, respectively).

CONCLUSION

Both approaches provide equal stimulation of the cochlear nerve and impedance.

Cochlear Implantation: The Volumetric Measurement of Vestibular Aqueduct and Gusher Prediction

This study aimed to validate the role of 3D segmentation in measuring the volume of the vestibular aqueduct (VAD), and the inner ear, and to study the correlation between VAD volume and VAD linear measurements at the midpoint and operculum. The correlation with other cochlear metrics was also studied. We retrospectively recruited 21 children (42 ears) diagnosed with Mondini dysplasia (MD) plus enlarged vestibular aqueduct (EVA) from 2009 to 2021 and who underwent cochlear implantation (CI). Patients' sociodemographic data were collected, and linear cochlear metrics were measured using Otoplan. Vestibular aqueduct width and vestibular aqueduct and inner ear volumes were measured by two independent neuro-otologists using 3D segmentation software (version 4.11.20210226) and high-resolution CT. We also conducted a regression analysis to determine the association between these variables and CT VAD and inner ear volumes. Among the 33 cochlear implanted ears, 13 ears had a gusher (39.4%). Regarding CT inner ear volume, we found that gender, age, A-value, and VAD at the operculum were statistically significant (p-Value = 0.003, <0.001, 0.031, and 0.027, respectively) by regression analysis. Moreover, we found that Age, H value, VAD at the midpoint, and VAD at the operculum were significant predictors of CT VAD volume (p-Value < 0.04). Finally, gender (OR: 0.092; 95%CI: 0.009-0.982; p-Value = 0.048) and VAD at the midpoint (OR: 0.106; 95%CI: 0.015-0.735; p-Value = 0.023) were significant predictors of gusher risk. Patients' gusher risk was significantly differentiated by gender and VAD width at the midpoint.

Safety of Cochlear Implantation in Children 12 Months or Younger: Systematic Review and Meta-analysis

OBJECTIVE

To systematically review the literature to determine safety of cochlear implantation in pediatric patients 12 months and younger.

DATA SOURCE

Ovid MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched from inception to March 20, 2021.

REVIEW METHODS

Studies that involved patients 12 months and younger with report of intraoperative or postoperative complication outcomes were included. Studies selected were reviewed for complications, explants, readmissions, and prolonged hospitalizations. Two independent reviewers screened all studies that were selected for the systematic review and meta-analysis. All studies included were assessed for quality and risk of bias.

RESULTS

The literature search yielded 269 studies, of which 53 studies underwent full-text screening, and 18 studies were selected for the systematic review and meta-analysis. A total of 449 patients and 625 cochlear implants were assessed. Across all included studies, major complications were noted in 3.1% of patients (95% CI, 0.8-7.1) and 2.3% of cochlear implantations (95% CI, 0.6-5.2), whereas minor complications were noted in 2.4% of patients (95% CI, 0.4-6.0) and 1.8% of cochlear implantations (95% CI, 0.4-4.3). There were no anesthetic complications reported across all included studies.

CONCLUSION

The results of this systematic review and meta-analysis suggest that cochlear implantation in patients 12 months and younger is safe with similar rates of complications to older cohorts.

Auditory and speech outcomes of cochlear implantation in post-meningitis deafness

PURPOSE

This study aims to identify the auditory, speech, and surgical outcomes of cochlear implantation in patients with profound SNHL following bacterial meningitis.

METHODS

Subjects with bilateral severe to profound SNHL who underwent unilateral cochlear implantation from 2003 to 2020 were included in this historical cohort study. The main outcomes were assessed using Categories of Auditory Performance (CAP) and Speech Intelligibility Ratings (SIR) scores. The CAP and SIR outcomes were collected as three-time points after surgery: 6, 12, and 24 months. In order to achieve the strength of the relationship and for computing the Risk Ratio (RR) by log-binominal regression method, we used two binary categorizations of CAP and SIR in our analyses.

RESULTS

The mean of age at implantation of the study and control group were 144.30 (156.90) and 121.10 (133.70) months, respectively. In the study group, 19 of 35 (54.3%) patients were male, and 16 (45.7%) were female. In the control group, 34 of 81 (42.0%) patients were male and 47 (58.0%) were female. The mean scores of CAP and SIR in our study improved significantly during the time in both groups. All p-values (p) were significant in both groups (T2 vs T1, T3 vs T1, and T3 vs T2). Our analysis by log-binomial regression and computing the RR based on the first and second categorization of CAP and SIR showed moderate to strong relationships between the presence of a history of meningitis and inappropriate CAP and SIR outcomes in these patients.

CONCLUSIONS

Although subjects who were deafened due to meningitis benefit significantly from cochlear implantation, we found moderate to strong relationships between the history of meningitis and inappropriate CAP and SIR outcomes in these patients.

Electrically evoked auditory brainstem responses in deaf patients with Mondini malformation during cochlear implantation

PURPOSE

To investigate the auditory pathway functions in deaf patients with Mondini malformation using the electrically evoked auditory brainstem response (EABR) during cochlear implantation (CI).

METHODS

A total of 58 patients with severe to profound sensorineural hearing loss (SNHL) were included in this study. Of these patients, 27 cases had Mondini malformation and 31 control cases had no inner ear malformations (IEMs). Intraoperative EABRs evoked by electrical stimulation at the round window niche (RWN) and round window membrane (RWM) were recorded.

RESULTS

Patients with Mondini malformation showed significantly lower EABR extraction rates than those with no IEMs did. However, for patients who showed EABRs, no significant difference in EABR thresholds, wave III (eIII) latencies, wave V (eV) latencies or eIII-eV latency intervals was found between two groups.

CONCLUSION

The physiological functions of the peripheral auditory system in patients with Mondini malformation may divide into opposite extremes, as revealed by a robust EABR and the absence of the EABR, respectively. The auditory conduction function should be objectively and individually evaluated for patients with Mondini malformation by the EABR.

Effect of cochlear implantation on vestibular function in children: A scoping review

OBJECTIVE

To provide a scoping review of the available literature for determining objectively the effect of cochlear implantation on vestibular function in children.

METHODS

A literature search was performed and the following criteria were applied: vestibular tests that were performed on subjects within the range of 0-18 years old before and after cochlear implantation. The papers conducted at least one of the following tests: (video) head impulse test, caloric test, cervical and ocular vestibular evoked myogenic potentials or rotatory chair test. Included papers underwent quality assessment and this was graded by risk of bias and directness of evidence.

RESULTS

Fourteen articles met the selection criteria. The included studies showed that cochlear implantation leads to a decrease in vestibular function in a proportion of the patient population. This loss of vestibular function can be permanent, but (partial) restoration over the course of months to years is possible. The pooling of data determined that the articles varied on multiple factors, such as time of testing pre- and post-operatively, age of implantation, etiologies of hearing loss, used surgical techniques, type of implants and the applied protocols to determine altered responses within vestibular tests. The overall quality of the included literature was deemed as high risk of bias and medium to low level of directness of evidence. Therefore, the data was considered not feasible for systematic analysis.

CONCLUSION

This review implicates that vestibular function is either unaffected or shows short-term or permanent deterioration after cochlear implantation in children. However, the heterogeneity of the available literature indicates the importance of standardized testing to improve our knowledge of the effect of cochlear implantation on the vestibular function and subsequent developmental consequences for the concerned children.

Cochlear Implant Complications in Children and Adults: Retrospective Analysis of 148 Cases

Objective

This study aimed to establish and discuss the intraoperative and postoperative complications affecting patients who underwent cochlear implant (CI) surgery from the Cochlear Implant Program of King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia.

Methods

A retrospective study was conducted by reviewing the medical records of 148 patients who underwent cochlear implantation at KAUH between 1999 and 2019. Postoperative complications were classified into minor and major complications. Minor complications resolved with minimal or no treatment. Major complications required additional surgery or hospitalization.

Results

Complications occurred in 28 (18.9%) patients. Minor complications occurred in 17 (11.5%) patients, which included otitis media (2%), facial palsy (1.4%), wound infection (1.4%), vertigo (1.4%), intraoperative cerebrospinal fluid (CSF) gusher (1.4%), tinnitus (1.4%), facial stimulation (1.4%), hematoma (0.7%), and chorda tympani nerve injury (0.7%). Major complications occurred in 11 (7.4%) patients. These included flap dehiscence/infection (2%), device failure (1.4%), device migration (1.4%), mastoiditis (1.4%), electrode damage during insertion (0.7%), and misplaced electrodes (0.7%).

Conclusion

This study reported a low rate of surgical complications associated with CI, and most have been managed successfully without further complications. Our results prove that CI is a safe and reliable procedure, with a low complications rate when performed by experienced surgeons.