Cochlear implant and inner ear malformation. Proposal for an hyperosmolar therapy at surgery

[Relationship between imaging features and intraoperative perilymph gusher in patients with Mondini inner ear malformation]

Objective:To investigate the relationship between imaging characteristics and intraoperative perilymph gusher in patients with Mondini inner ear malformation in cochlear implantation, in order to provide basis and clinical guidance for predicting of intraoperative perilymph gusher before cochlear implantation. Methods:According to Sennaroglu's classification method, children with severe sensorineural hearing loss screened from January 2020 to December 2021 were divided into Mondini group, simple enlarged vestibular aqueduct group and normal inner ear group according to inclusion criteria strictly. The images of temporal bone HRCT and inner ear MRI were post-processed, some relative indicators were measured, including cochlear height and width of vestibular aqueduct, etc., and the gusher situation during cochlear implantation was recorded. The mean value of each indicator among the three groups were compared respectively, and the differences of each indicator between the gusher group and the non-gusher group were analyzed. Results:There were statistically significant differences in cochlear height, length of cochlear bottom turn, width of cochlear aperture, vestibular length and vestibular width among the Mondini group（24 cases）, simple EVA group（15 cases） and normal inner ear group（28 cases）. The incidence of gusher of Mondini group in cochlear implantation was 30.77%（8/26）. The outer diameter of the VA（[3.10±0.74]mm） and the middle width of the VA（[1.90±0.68] mm） in the gusher group were wider than those in the non-gusher group, and the difference was statistically significant. The incidence of intraoperative gusher in patients with EVA was 20.00%（3/15）, and there was statistically significant difference in the length of endolymph sac between gusher group and non-gusher group（P<0.05）. Conclusion:The causes of intraoperative perilymph gusher in patients with Mondini inner ear malformation are complex. The enlarged vestibular aqueduct may be one of the anatomical basis. Whether it can be used to guide the preoperative assessment of the risk of intraoperative perilymph gusher need to be further confirmed by a large sample of clinical research from multiple centers in the future.

Anatomical Variations, Surgical Difficulties, and Complications Associated with Cochlear Implantation in Different Age Groups of the Pediatric Population of Nepal: A Tertiary Level Hospital-Based Study

Pediatric cases account for the major proportion of the population for whom cochlear implantation is indicated. This study aims to review the anatomical variations, surgical difficulties, and complications associated with cochlear implantation surgery in different age groups of the pediatric population of Nepal.This study was conducted at Tribhuvan University Teaching Hospital, Nepal. A prospectively set data of cases who underwent cochlear implantation between January 2015 and March 2020 were analyzed for details of surgical procedure, surgical difficulties, and intraoperative and postoperative complications. The anatomical variations encountered during surgery were classified as: developmental anomalies, round window niche variations and acquired abnormalities resulting from inflammation. Intraoperative surgical difficulties were defined based on the operating surgeon's perspective. Complications following cochlear implantation were classified as surgical and nonsurgical or device-related. We used SPSS version 25 for the analysis of our data. Chi-square test and Fisher's exact test were used to analyze the statistical association.The most commonly encountered difficulty was the requirement of an extended posterior tympanotomy approach due to poor visualization of round window niche. There was a statistically significant association of difficult insertion of electrodes with round window niche visibility. The common complications encountered were intraoperative facial nerve exposure, bleeding, electrode-related problems, cerebrospinal fluid gusher, and device failure.Cochlear implantation with an experienced surgeon in pediatric population is a relatively safe procedure. There is no association of the difficulties and complications related to surgery with the different age groups.

Feasibility of day-case pediatric cochlear implantation

PURPOSE

Pediatric cochlear implantation is performed on an outpatient basis in an inconstant way. The aim of this study is to assess the feasibility of day-case pediatric cochlear implantation by determining the acceptability of outpatient-to-inpatient conversion rate (acceptability threshold of 5%) and to assess the safety by comparing outpatient and inpatient postoperative events. We also want to identify conversion predictive factors.

METHODS

We conducted a monocentric retrospective study including 267 cases aged 6 months to 18 years who underwent unilateral cochlear implantation between 2016 and 2020. This population was divided into two groups: outpatient group (190 cases) and inpatient group (77 cases).

RESULTS

Among the 190 cases scheduled as day surgery, 9 cases required conversion to conventional hospitalization which leads to an outpatient-to-inpatient conversion rate of 4.7%. Postoperative nausea and vomiting (PONV) were involved in all cases of conversion. Conversion predictive factors were the presence of an inner ear malformation at risk of gusher (OR 32.51, 95% CI [4.98-370.27], p 0.001) and the intraoperative administration of morphine (OR 8.52, 95% CI [1.38-86.84], p 0.035). There was no statistically significant difference in immediate postoperative complications (outpatient 14.2% vs inpatient 16.9% p 0.715), early-stage complications (outpatient 12.6% vs inpatient 10.4% p 0.812) and early-stage unplanned consultations (outpatient 4.7% vs inpatient 3.9% p 0.748) between outpatient and inpatient groups. Unplanned readmissions were found only in the outpatient group.

CONCLUSION

Day-case pediatric cochlear implantation is a feasible and safe procedure even in infants. The outpatient-to-inpatient conversion rate of 4.7% is considered acceptable but requires anticipation of human and accommodation needs. No causes of conversion were life-threatening. The risk of postoperative complications and unplanned consultations are not influenced by the mode of hospitalization. Special attention should be paid to the prevention of PONV and the presence of inner ear malformations.

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.

Repair of Cerebrospinal Fluid Leak in Cochlear Implantation

OBJECTIVE

The aim of this study is to evaluate the treatment of cerebrospinal fluid (CSF) leaks from cochleostomy after cochlear implantation intraoperatively and postoperatively.

METHODS

Three hundred seven patients (age ranges 13 months to 18 years) were undergone cochlear implantation and 14 (4.56%) of them had CSF leakage intraoperatively (2 normal, 12 anomalous cochlea). Complete packing of the around electrode in cochleostomy with muscle had performed to control CSF leak intraoperatively for primary surgery in 10 patients. Cerebrospinal fluid leakage was observed in 3 patients after cochlear implantation postoperatively. Revision surgeries for CSF leakage with fat tissue sealing were performed for them also. Fat tissue packing was performed for the last 4 patients in primary surgery. Outcomes of management methods for sealing were evaluated.

RESULTS

Sealing the cochleostomy with muscle was performed for 10 patients. Fibrin glue applications were used for excessive leakage for 5 patients with cochlear anomalies and 3 of these patients had CSF leak from cochleostomy postoperatively (Patients I, II, III). Secondary surgeries with fat tissue sealing were performed. But CSF leakage also was occurred in Patient III. Subtotal petrosectomy and obliteration of cavity with fat tissue had been performed for Patient III. Cerebrospinal fluid leakage has not been seen in primary surgeries with fat tissue packing in other 5 patients.

CONCLUSION

Cerebrospinal fluid leakage may occur in cochlear implantation patients with inner ear anomalies postoperatively. Sealing of the cochleostomy with fat tissue is more useful than muscle intraoperatively.

Cochlear Implantation in Inner Ear Malformations: Systematic Review of Speech Perception Outcomes and Intraoperative Findings

Objective

(1) To analyze reported speech perception outcomes in patients with inner ear malformations who undergo cochlear implantation, (2) to review the surgical complications and findings, and (3) to compare the 2 classification systems of Jackler and Sennaroglu.

Data Sources

PubMed, Scopus (including Embase), Medline, and CINAHL Plus.

Review Methods

Fifty-nine articles were included that contained speech perception and/or intraoperative data. Cases were differentiated depending on whether the Jackler or Sennaroglu malformation classification was used. A meta-analysis of proportions examined incidences of complete insertion, gusher, and facial nerve aberrancy. For speech perception data, weighted means and standard deviations were calculated for all malformations for short-, medium-, and long-term follow-up. Speech tests were grouped into 3 categories—closed-set words, open-set words, and open-set sentences—and then compared through a comparison-of-means t test.

Results

Complete insertion was seen in 81.8% of all inner ear malformations (95% CI: 72.6-89.5); gusher was reported in 39.1% of cases (95% CI: 30.3-48.2); and facial nerve anomalies were encountered in 34.4% (95% CI: 20.1-50.3). Significant improvements in average performance were seen for closed- and open-set tests across all malformation types at 12 months postoperatively.

Conclusions

Cochlear implantation outcomes are favorable for those with inner ear malformations from a surgical and speech outcome standpoint. Accurate classification of anatomic malformations, as well as standardization of postimplantation speech outcomes, is necessary to improve understanding of the impact of implantation in this difficult patient population.

Cerebrospinal Fluid Leak in Cochlear Implantation: Enlarged Cochlear versus Enlarged Vestibular Aqueduct (Common Cavity Excluded)

Objective. To share our experience of cerebrospinal fluid gusher in cochlear implantation in patients with enlarged cochlear or vestibular aqueduct. Study Design. Case series with comparison and a review of the literature. Methods. A retrospective study was performed. Demographic and radiological results of patients with enlarged cochlear aqueduct or enlarged vestibular aqueduct in 278 consecutive cochlear implant recipients, including children and adults, were evaluated between January 2000 and December 2015. Results. Six patients with enlarged cochlear aqueduct and eight patients with enlarged vestibular aqueduct were identified. Cerebrospinal fluid gusher occurs in five subjects with enlarged cochlear aqueduct and in only one case of enlarged vestibular aqueduct. Conclusion. Based on these findings, enlarged cochlear aqueduct may be the best risk predictor of cerebrospinal fluid gusher at cochleostomy during cochlear implant surgery despite enlarged vestibular aqueduct.

Cochlear Implantation in Isolated Large Vestibular Aqueduct Syndrome: Report of Three Cases and Literature Review

Introduction Large vestibular aqueduct syndrome (LVAS) is characterized by the enlargement of the vestibular aqueduct associated with sensorineural hearing loss. It is the most common radiographically detectable inner ear anomaly in congenital hearing loss. LVAS may occur as an isolated anomaly or in association with other inner ear malformations.

Objective To report three cases of isolated LVAS with a focus on preoperative assessment, surgical issues, and short-term postoperative follow-up with preliminary auditory habilitation outcomes.

Resumed Report One girl and two boys with LVAS were assessed and cochlear implantation was performed for each. Various ways of intraoperative management of cerebrospinal fluid gusher and postoperative care and outcomes are reported.

Conclusion Cochlear implantation in the deaf children with LVAS is feasible and effective.

Early complications following cochlear implantation in children and their management

OBJECTIVES

To report the early postoperative complications of cochlear implantation (CI) in the pediatric population and discuss the intervention measures.

METHODS

We retrospectively analyzed 260 consecutive pediatric cochlear implantations performed at the First Affiliated Hospital of Zhengzhou University between March 2010 and July 2013. All patients were younger than 12 years old at the time of implantation, with a mean age of 4.3 years, and 47 cases had inner ear malformations. Complications correlated to age at CI and inner ear malformations were analyzed using the χ(2) test.

RESULTS

Of the 260 patients, early postoperative complications were observed in 17 (6.54%) cases, of which 16 (6.15%) were minor and one (0.38%) was major, none required surgical device removal or reimplantation. Among the 16 minor complications, transient vertigo was the most common (nine cases, 3.46%), three (1.15%) of them with severe CSF gusher during the surgery; followed by transient facial nerve palsy (two cases, 0.77%, both were reversible); external auditory canal injury, subcutaneous hematoma each in two cases (0.77%), and minor dural injury in one case (0.38%). One major complication included an epidural hematoma in a 7-year-old boy who recovered completely without any neurologic deficits following immediate evacuation. Inner ear malformations were significantly associated with the surgical complications, especially vertigo and gusher (P<0.05).

CONCLUSIONS

Cochlear implantation in children is fairly a safe procedure with a relatively low complication rate. The most common early postoperative complications are minor, but serious and life threatening complications rarely may occur. Awareness of complications helps clinicians to adopt the specific preventive measures and immediate interventions so that the outcome will be successful.

Cerebrospinal fluid gusher in cochlear implantation

OBJECTIVES

To share our experience of cerebrospinal fluid (CSF) gusher in cochlear implantation.

METHODS

Demographic, radiological, and surgical results of patients with CSF gusher in 523 consecutive cochlear implant recipients including children and adults as well as our management technique were evaluated and a review of the literature has been included.

RESULTS

Fifteen (2.87%) cases had CSF gusher. Two patients (13.3%) were adults with post-lingual hearing loss and the rest 12 (86.7%) were children with congenital hearing loss. Twelve patients (80%) had various types of inner ear malformation. Three patients (20%) had no predictable risk of CSF gusher from history or pre-operative imaging. In all patients, CSF gushers were controlled with our technique of packing the electrode entrance site with no additional measures.

CONCLUSION

CSF gusher may occur with post-lingual hearing loss and in children with apparently unremarkable imaging and history. Thus, surgeons should always be ready to manage it. Management of CSF gusher can be mainly performed during the initial surgery by precise tight packing of the electrode entrance site. Furthermore, non-surgical or surgical measures are rarely required to stop a persistent leak. Our results show that our management technique may be recommended as well.

Cochlear implantation in a patient with severe cochlear hypoplasia

Objective:

We report the case of a successful cochlear implantation in a patient with severe cochlear hypoplasia.

Case report:

The outcome of cochlear implantation is generally less favourable for patients with cochlear hypoplasia than for those with a normal cochlear structure. In the reported patient, part of the electrode array was inserted into the internal auditory canal. Nevertheless, the benefits following cochlear implantation seemed to outweigh the risks for this patient.

Conclusion:

Cochlear hypoplasia is not necessarily a contraindication for cochlear implantation.

Cochlear Implantation in Children with Anomalous Cochleovestibular Anatomy

Objective. To determine the influence of inner ear dysplasia on both surgical and audiologic outcomes following pediatric cochlear implant (CI) surgery.

Data Sources. MEDLINE (1982-2009) and data from Massachusetts Eye and Ear Infirmary.

Review Methods. A systematic review of the literature was performed. Variables assessed included age at implantation, duration of CI use, radiologic and operative findings, and speech perception outcome data.

Results. The initial search yielded 1326 articles. Including data from our own study, twenty-two fulfilled criteria for inclusion, representing 311 patients. Data for bilateral implants were recorded only for the first implant. Data on simultaneous bilateral implants were not recorded. The most common anomaly seen was large vestibular aqueduct (89/311 or 29%). When comparing patients with mild-moderate or severe dysplasia, rates of cerebrospinal fluid gusher were 31% versus 35% (odds ratio [OR] = 0.50), anomalous facial nerve anatomy was seen in 11% versus 51% (OR = 0.15), and postoperative speech perception abilities were found in 84% versus 54% (OR = 1.93), respectively. A large heterogeneity was found among studies regarding all outcome measures.

Conclusion. Although we found that severe inner ear dysplasia was associated with increased surgical difficulty and lower speech perception, the lack of uniformity in published clinical data limited the strength of these results. Standardization of surgical and radiologic reporting as well as more consistent speech perception testing is needed to better determine the association between anomalous cochleovestibular anatomy and clinical outcomes.

Revision surgeries and medical interventions in young cochlear implant recipients

OBJECTIVE

To report devices failures and postoperative or medical complications after cochlear implantation in children and to discuss revision surgeries and medical interventions occurring during follow-up.

METHODS

In this retrospective study in a tertiary referral pediatric hospital, we included a consecutive sample of children younger than 15 years old who received implants between January 1994 and June 2010. All complications and treatments were systematically reviewed.

RESULTS

One hundred and forty children were included in this study. Four children received bilateral cochlear implantation. Mean age at implantation was 43.6 months (age ranged from 11 months to 15 years). Overall, 74 children were boys (52.1%) and 35 children (25%) received implants before the age of two. Inner ear malformations were found in 19 children (13.5%), while 18 children (12.9%) experienced complications: cochlear reimplantations (n=8), other revision surgeries (n=3) and medical treatment (n=7). Excluding device failures, 13 children (9.2%) experienced complications. Postoperative infection was the principal cause of these complications (10 cases). Four children younger than 2 years at implantation suffered complication postoperatively. In these children, there was no statistically significant increase in complications compared to older children (P>0.05). Complete electrode insertion was achieved in 7 of the 8 reimplanted children.

CONCLUSION

Cochlear implantation could be considered a safe and reliable rehabilitation for deafened young children. Reimplantation was feasible and complete electrode insertion was achievable. Long-term follow up was mandatory to minimize and control surgical complication.