Management of surgical difficulties during cochlear implant with inner ear anomalies

Aberrant Course of the Intratemporal Facial Nerve in Children with Congenital Hearing Loss

Congenital facial nerve (FN) malformations are uncommon. Our aim is to determine the clinical and radiological features of FN malformations along with the associated cochlear and vestibular malformations. We conducted a retrospective study including children with a profound sensorineural hearing loss who were candidates for cochlear implantation. We evaluated the presence of FN malformations through temporal bone computed tomography scan and magnetic resonance imaging. We recorded an aberrant FN course in five out of 165 patients in a total of 9 ears. They consisted of a bifurcation of the mastoid segment, an anterior or posterior displacement of the labyrinthine segment and a hypoplasia of the geniculate ganglion. Associated inner ear malformations included vestibular aqueduct dilation, cochlear hypoplasia and total labyrinthine aplasia. We noted a bilateral agenesis of the cochlear nerve in three patients. Facial nerve malformations should be suspected in patients presenting a congenital hearing loss especially in association with other temporal bone malformations. Their pre-operative discovery is helpful in planning the surgical procedure.

Incidence of Cochlear Implantation Complications in Saudi Arabia: A Comprehensive Systematic Review of the Literature

This review aimed to determine the incidence of complications associated with cochlear implants (CI) in Saudi Arabia. We systematically searched PubMed, AIRE, OaIster, MEDLINE, Directory of Open Access Journals, Scopus, and Ovid from inception to January 2024. The review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (ID: CRD42023486687). Studies that reported CI complications in Saudi Arabia were included. This systematic review was conducted in accordance with PRISMA guidelines. A total of 17 articles with 2216 patients were included. The most common intraoperative complication was cerebrospinal fluid leakage (23 patients, 0.99%), followed by surgical difficulties (six patients, 0.26%), and dural accidental exposure and bleeding (three patients, 0.13%); the most common postoperative complications were vestibular symptoms (20 patients, 0.86%), followed by infection (17 patients, 0.73%), and device malfunction or migration (12 patients, 0.52%). The total complication rate ranged from 4-13%. Most of the included studies had a low risk. CI in Saudi Arabia has a complication rate similar to that reported in international studies. This review emphasizes the need for continued surveillance of CI outcomes to optimize procedural techniques and improve the safety and efficacy of CI in Saudi Arabia.

Computed tomography multi-planar and 3D image assessment protocol for detailed analysis of inner ear malformations in patients undergoing cochlear implantation counseling

<b><br>Introduction:</b> Congenital inner ear malformations resulting from embryogenesis may be visualized in radiological scans. Many attempts have been made to describe and classify the defects of the inner ear based on anatomical and radiological findings.</br> <b><br>Aim:</b> The aim was to propose and discuss computed tomography multi-planar and 3D image assessment protocols for detailed analysis of inner ear malformations in patients undergoing cochlear implantation counseling.</br> <b><br>Material and methods:</b> A retrospective analysis of 22 malformed inner ears. CT scans were analyzed using the Multi-Planar Reconstruction (MPR) option and 3D reconstruction.</br> <b><br>Results:</b> The protocol of image interpretation was developed to allow reproducibility for evaluating each set of images. The following malformations were identified: common cavity, cochlear hypoplasia type II, III, and IV, incomplete partition type II and III, and various combinations of vestibule labyrinth malformations. All anomalies have been presented and highlighted in figures with appropriate descriptions for easier identification. Figures of normal inner ears were also included for comparison. 3D reconstructions for each malformation were presented, adding clinical value to the detailed analysis.</br> <b><br>Conclusions:</b> Properly analyzing CT scans in cochlear implantation counseling is a necessary and beneficial tool for appropriate candidate selection and preparation for surgery. As proposed in this study, the unified scans evaluation scheme simplifies the identification of malformations and reduces the risk of omitting particular anomalies. Multi-planar assessment of scans provides most of the necessary details. The 3D reconstruction technique is valuable in addition to diagnostics influencing the decision-making process. It can minimize the risk of misdiagnosis. Disclosure of the inner ear defect and its precise imaging provides detailed anatomical knowledge of each ear, enabling the selection of the appropriate cochlear implant electrode and the optimal surgical technique.</br>.

Complications of cochlear implants: a MAUDE database study

OBJECTIVE

A retrospective cross-sectional analysis was conducted of the US Food and Drug Administration's MAUDE (Manufacturer and User Facility Device Experience) database, to evaluate the complication profile of cochlear implantation according to manufacturer.

METHODS

A review of the MAUDE database was conducted from 1 January 2010 to 31 December 2020. Complications, including infection, extrusion, facial nerve stimulation, meningitis and cerebrospinal fluid leak, were identified using key word searches. The categorised data were analysed using a chi-square test to determine a difference in global complication incidence between three major cochlear implant manufacturers: manufacturer A (Cochlear Limited), manufacturer B (Med-El) and manufacturer C (Advanced Bionics).

RESULTS

A total of 31 857 adverse events were analysed. Implants of manufacturer C were associated with a statistically higher rate of infection (0.97 per cent), cerebrospinal fluid leak (0.07 per cent), extrusion (0.44 per cent) and facial nerve stimulation (0.11 per cent). Implants of manufacturer B were associated with a statistically higher rate of meningitis (0.07 per cent).

CONCLUSION

Consideration of patient risk factors along with cochlear implant manufacturers can heighten awareness of cochlear implant complications pre-operatively, intra-operatively and post-operatively.

Association of Ear Anomalies and Hearing Loss Among Children With 22q11.2 Deletion Syndrome

OBJECTIVE

To identify inner and middle ear anomalies in children with 22q11.2 deletion syndrome (22q11DS) and determine associations with hearing thresholds.

STUDY DESIGN

Retrospective study.

SETTING

Two tertiary care academic centers.

METHODS

Children presenting with 22q11DS between 2010 and 2020 were included. Temporal bone imaging with computed tomography or magnetic resonance imaging was reviewed by 2 neuroradiologists.

RESULTS

Twenty-two patients (12 female, 10 male) were identified. Forty-four ears were evaluated on imaging. There were 15 (34%) ears with abnormal semicircular canals, 14 (32%) with abnormal vestibules, 8 (18%) with abnormal ossicles, 6 (14%) with enlarged vestibular aqueducts, 4 (9.1%) with abnormal facial nerve canals, and 4 (9.1%) with cochlear anomalies. There were 25 ears with imaging and audiometric data. The median pure tone average (PTA) for ears with any structural abnormality was 41.0 dB, as compared with 28.5 dB for ears without any structural abnormality (P = .21). Of 23 ears with normal imaging, 6 (26%) had hearing loss in comparison with 13 (62%) of 21 ears with abnormalities (P = .02). Total number of anomalies per ear was positively correlated with PTA (Pearson correlation coefficient, R = 0.479, P = .01). PTA was significantly higher in patients with facial nerve canal anomalies (P = .002), vestibular aqueduct anomalies (P = .05), and vestibule anomalies (P = .02).

CONCLUSIONS

Semicircular canal, ossicular, vestibular aqueduct, and vestibular anomalies were detected in children with 22q11DS, especially in the setting of hearing loss. Careful evaluation of anatomic anomalies is needed prior to surgical intervention in these patients.

Cochlear implantation in adults and pediatrics with enlarged vestibular aqueduct: a systematic review on the surgical findings and patients' performance

PURPOSE

Cochlear implantation (CI) has been considered a safe and effective management option for patients with severe to profound hearing loss. Patients with enlarged vestibular aqueduct (EVA) could be challenging with some variations in surgical approaches, intraoperative surgical notes, and clinical outcomes. This study aimed to  review the surgical and clinical outcomes of cochlear implantation among patients with EVA.

MATERIALS AND METHODS

A systematic literature search was carried out in five major databases. All original studies reporting cochlear implantation in patients with EVA were included for qualitative data synthesis. The risk of bias was independently assessed through the National Intuitional of Health tool. The review protocol was registered in PROSPERO (reference number: CRD42021225900).

RESULTS

A total of 34 studies with 4035 subjects were included. Of them, 853 (21.14%) had EVA and underwent CI. Mondini malformation was the most frequently associated anomaly (n = 78, 11.1%). Unilateral implantation was performed in 258 cases while bilateral in 119 subjects. Postoperative complications included CSF/perilymph gusher (n = 112), CSF oozing (n = 18), and partial electrode insertion (n = 6). Closing the cochleostomy with temporalis fascia, muscle, connective tissue, or fibrin glue was the most frequently reported approach to manage CSF/perilymph gusher (n = 67, 56.7%) while packing was performed in six patients.

CONCLUSION

Patients with EVA demonstrated audiometric and speech performance improvement after CI. However, many patients had intra- or postoperative complications. Further research is needed as the outcomes may be affected by associated temporal bone pathology, the timing of implant, and hearing condition.

A novel three-step process for the identification of inner ear malformation types

Objective

We hypothesize that visualizing inner-ear systematically in both cochlear view (oblique coronal plane) and in mid-modiolar section (axial plane) and following three sequential steps simplifies, identification of inner-ear malformation types.

Methods

Pre-operative computer-tomography (CT) scans of temporal bones of 112 ears with various inner ear malformation (IEM) types were taken for analysis. Images were analyzed using DICOM viewers, 3D slicer, and OTOPLAN®. The inner-ear was captured in the oblique-coronal plane for the measurement of length and width of cochlear basal turn which is also called as A-, and B-values respectively (Step 1). In the same plane, the angular-turns of lateral-wall (LW) of cochlear basal turn were measured (Step 2). As Step 3, the mid-modiolar section of inner ear was captured in the axial plane by following the A-value and perpendicular to cochlear view. From the mid-modiolar section, the outer-contour of inner ear was captured manually by following contrasting gray area between fluid filled and bony promontory and was compared to known resembling objects to identify IEM types (Step 3).

Results

Following reference values have emerged from our analysis: A-, and B-values (Step 1) on average are >8 mm and >5.5 mm respectively, in normal cochleae (NA), enlarged vestibular aqueduct syndrome (EVAS), incomplete partition (IP) type-I and -II, whereas it is <8 mm and <5.5 mm respectively, in IP type-III and cochlear hypoplasia (CH). Angular-turn of LW is consistently observed in cochlear basal turn (Step 2), is 540° in NA and EVAS, 450° in IP-II, and 360° in IP types I & III. In subjects with CH type, angular-turn of LW is either 360° or 450° or 540°. In true mid-modiolar section, outer-contour of inner-ear (Step-3), other than in CH and cystic inner-ear malformations, resembles recognizable shapes of known objects. Absence of EVA is an additional characteristic that confirms diagnosis of CH when the A-, B-values, and angular-turn of LW can be similar to other anatomical types. Drawing a straight line along posterior edge of internal auditory canal (IAC) in axial view can differentiate a true common cavity (CC) from cochlear aplasia-vestibular cavity (VC).

Conclusion

Three-step process proposed in this study captures inner-ear in cochlear view as well in mid-modiolar sections visualizing key features of inner-ear in identification of IEM types.

Level of Evidence

Level 1.

Systematic review of cochlear implantation in patients with inner ear malformations

OBJECTIVES

To evaluate the outcomes of cochlear implantation in patients with severe to profound sensorineural hearing loss due to inner ear malformations (IEMs) when compared to patients without IEMs. We discussed audiological outcomes such as open-set testing, closed-set testing, CAP score, and SIR score as well as postoperative outcomes such as cerebrospinal fluid gusher and incomplete insertion rate associated with cochlear implantation in individuals with IEMs.

DATA SOURCES

PubMed, Science Direct, Web of Science, Scopus, and EMBASE databases.

REVIEW METHODS

After screening a total of 222 studies, twelve eligible original articles were included in the review to analyze the speech and hearing outcomes of implanted patients with IEMs. Five reviewers independently screened, selected, and extracted data. The "Tool to Assess Risk of Bias in Cohort Studies" published by the CLARITY group was used to perform quality assessment on eligible studies. Systematic review registration number: CRD42021237489.

RESULTS

IEMs are more likely to be associated with abnormal position of the facial nerve, raising the risk of intraoperative complications. These patients may benefit from cochlear implantation, but audiological outcomes may also be less favorable than in individuals without IEMs. Furthermore, due to the risk of cerebrospinal fluid gusher, incomplete insertion of electrodes, and postoperative facial nerve stimulation, surgeons can employ precautionary measures such as preoperative imaging and proper counseling. Postoperative imaging is suggested to be beneficial in ensuring proper electrode placement.

CONCLUSIONS

Cochlear implants (CIs) have the potential to provide auditory rehabilitation to individuals with IEMs. Precise classification of the malformation, preoperative imaging and anatomical mapping, appropriate electrode selection, intra-operative techniques, and postoperative imaging are recommended in this population.

Effects of Age on Delayed Facial Palsy After Otologic Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

To report 4 cases of delayed facial palsy (DFP) after pediatric middle ear (ME) surgery and systematically review and analyze the associated literature to evaluate the effects of age on DFP etiology, management, and prognosis.

METHODS

Systematic review of PubMed, Cochrane Library, and Embase for articles related to DFP after cochlear implantation (CI) was performed. These articles were assessed for level of evidence, methodological limitations, and number of cases. Meta-analysis was performed to assess the effects of age on DFP incidence. Furthermore, a comprehensive list of all pediatric DFP cases after otologic surgery was assembled through a multi-institutional retrospective review and systematic review of the literature.

RESULTS

Twenty-nine articles fit the criteria for inclusion in the meta-analysis. The incidence of DFP after CI was 0.23% and 1.01% for pediatric and adult cases, respectively. This difference was statistically significant (P < .001, odds ratio 4.36). Twenty-three cases, adding to the 4 presented herein, were suitable for a comprehensive list. The mean age was 6.9 years. Average postoperative day of paresis onset was 5.4, with an average maximum House-Brackmann grade of 3.5. All patients obtained full facial recovery after an average of 23.5 days.

CONCLUSIONS

The systematic review demonstrates that DFP after pediatric CI is rare and occurs at a significantly lower rate than in adults, further supporting the viral reactivation hypothesis of DFP. The prognosis for pediatric DFP after otologic surgery is excellent, with a high rate of full recovery in a short time frame. However, steroid administration can be considered.

LEVEL OF EVIDENCE

IIa.

Feasibility of Day Surgery for Cochlear Implantation under Conscious Sedation with Same-Day Fitting

OBJECTIVES

To evaluate the feasibility of performing cochlear implantation under conscious sedation (CS) as day surgery with same-day fitting.

MATERIALS AND METHODS

All patients underwent cochlear implantation under CS between November 2017 and April 2018. The data collected included demographic information, preoperative clinical characteristics, surgical details, postoperative fitting information, and side effects, if any.

RESULTS

Nine patients had 11 cochlear implants (CIs) placed under CS (2 patients received bilateral CIs). One patient's data were excluded from the audiological results because conversion to general anesthesia (GA) was necessary. One patient (11%) vomited just before the end of the procedure. Seven patients had uneventful procedures. Eight (88%) patients were discharged home the same day. There was a statistically significant difference in recovery time between the CS group and the GA group (t=-2.26, df=12, p<0.05). In the CS group, there was no statistically significant change in the maximum comfortable loudness level for all electrodes from the day of the surgery to the following day. However, there was a statistically significant difference in the threshold levels of all electrodes from the day of the surgery to the following day (Z=-2.04, N=120, p<0.05). Further analysis revealed a statistically significant difference in the four most apical electrodes (Z=-3.496, N=40, p<0.0001), but not in the middle or basal electrodes.

CONCLUSION

Cochlear implantation can be performed under CS with careful patient selection. This approach facilitates same-day fitting and day surgery by minimizing comorbidity.

Cochlear Implantation in Pediatric Patients With Enlarged Vestibular Aqueduct: A Systematic Review

OBJECTIVE(S)

To describe cochlear implantation (CI) outcomes, with speech perception, auditory, language, and parent-reported auditory and speech behaviors, in children with an enlarged vestibular aqueduct (EVA) and incomplete partition type 2 (IP-II) and compare to control children without inner ear malformations (IEMs) and to determine cerebrospinal fluid gusher rates and effect on outcomes.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, Embase, Cochrane, and CINAHL databases were searched from inception to February 2020. Studies reporting relevant outcomes in children with EVA or EVA + IP-II and controls without IEMs undergoing CI were included. Mean differences in speech perception, auditory, and language scores between cases and controls were meta-analyzed. Gusher rates were determined by proportion meta-analyses.

RESULTS

Of 214 identified articles, 42 met inclusion criteria, evaluating 775 cases and 2,191 controls. Of -cases, 578 (74.6%) had EVA and 197 (25.4%) had EVA + IP-II. Cases showed a significant improvement in speech perception, auditory and language performance, comparable to controls. Parent-reported auditory and speech production behaviors outcomes were positive among cases and comparable to controls. Pooled gusher proportions in EVA and EVA + IP-II cases were 27.7% (95% CI: 17.6-39.1) and 48.6% (95% CI: 28.6-69.0), respectively, with a proportion difference of 20.9% (95% CI: 11.0-30.1). Gusher occurrence did not impact speech perception or language outcomes.

CONCLUSION

Outcomes in children with EVA or EVA + IP-II undergoing CI are favorable and largely comparable to outcomes in children with hearing loss undergoing CI without IEMs. Intraoperative gusher is more prevalent among children with EVA + IP-II as compared to iEVA. Gusher does not influence speech perception and language development outcomes.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

Phosphatidylinositol 4-kinase β mutations cause nonsyndromic sensorineural deafness and inner ear malformation

Congenital hearing loss is a common disorder worldwide. Heterogeneous gene variation accounts for approximately 20-25% of such patients. We investigated a five-generation Chinese family with autosomal-dominant nonsyndromic sensorineural hearing loss (SNHL). No wave was detected in the pure-tone audiometry, and the auditory brainstem response was absent in all patients. Computed tomography of the patients, as well as of two sporadic SNHL cases, showed bilateral inner ear anomaly, cochlear maldevelopment, absence of the osseous spiral lamina, and an enlarged vestibular aqueduct. Such findings were absent in nonaffected persons. We used linkage analysis and exome sequencing and uncovered a heterozygous missense mutation in the PI4KB gene (p.Gln121Arg) encoding phosphatidylinositol 4-kinase β (PI4KB) from the patients in this family. In addition, 3 missense PI4KB (p.Val434Gly, p.Glu667Lys, and p.Met739Arg) mutations were identified in five patients with nonsyndromic SNHL from 57 sporadic cases. No such mutations were present within 600 Chinese controls, the 1000 genome project, gnomAD, or similar databases. Depleting pi4kb mRNA expression in zebrafish caused inner ear abnormalities and audiosensory impairment, mimicking the patient phenotypes. Moreover, overexpression of 4 human missense PI4KB mutant mRNAs in zebrafish embryos resulted in impaired hearing function, suggesting dominant-negative effects. Taken together, our results reveal that PI4KB mutations can cause SNHL and inner ear malformation. PI4KB should be included in neonatal deafness screening.

Pre- and post-operative imaging of cochlear implants: a pictorial review

Cochlear implants are increasingly used to treat sensorineural hearing disorders in both children and adults. Pre-operative computed tomography and magnetic resonance imaging play a pivotal role in patient selection, to rule out findings that preclude surgery or identify conditions which may have an impact on the surgical procedure. The post-operative position of the electrode array within the cochlea can be reliably identified using cone-beam computed tomography. Recognition of scalar dislocation, cochlear dislocation, electrode fold, and malposition of the electrode array may have important consequences for the patient such as revision surgery or adapted fitting.

Outcomes of cochlear implantation in children with inner ear malformations

PURPOSE

To evaluate the surgical experience and auditory functions and progress of speech development of cochlear implantation in malformed ears.

MATERIALS AND METHODS

Between November 1995 and July 2017, thirty-seven patients (26 females and 11 males; mean age: 138.275 ± 96.24 months) with diverse anomalies of the inner ear were retrospectively examined for surgical and audiological results. Speech Intelligibility Rating (SIR), Categories of Auditory Perception (CAP), Pure Tone Average (PTA), Speech Intelligibility Rating (SRT), and Word Discrimination Score (WDS) were the audiological tests used to evaluate the efficacy of CI in the malformed inner ears.

RESULTS

CSF gusher was experienced by six patients (three with LVA (large vestibular aqueduct), one with IP (incomplete partition) I, and two with both IP II Mondini malformations and LVA). Two patients had transient facial paresis after surgery. All patients fully recovered within 6 months. The postoperative PTA, SRT, and WDS test results showed significant differences between progressive and congenital sensorineural hearing loss (p values < 0.05 for all). On the other hand, the postoperative CAP and SIR test results revealed no significant differences between the two groups. According to etiology, the PTA and SRT values were significantly lower in common cavity patients than the LVA patients (p values < 0.01); no significant differences were found among the other etiological groups.

CONCLUSIONS

Cochlear implantation is safe in children with inner ear malformations. However, the success rate is low compared to patients with normal anatomy in terms of audiological results; the most successful group of patients with inner ear malformation is large vestibular aqueduct.