Long-term results of the transattical approach: an alternative technique for cochlear implantation

Various approaches to the round window for cochlear implantation: a systematic review

OBJECTIVE

Round window approaches are used to insert a cochlear implant electrode array into the scala tympani. This study aimed to review the literature to find the reported round window approaches.

METHOD

This review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses ('PRISMA') guidelines. Articles that described their surgical approach to the round window were included. The PubMed, Scopus, Web of Science and Cochrane Library electronic databases were searched through to June 2021. The study protocol was registered on Prospero (reference number: CRD42021226940).

RESULTS

A total of 42 reports were included. The following approaches were documented: the standard facial recess, keyhole, retrofacial, modified suprameatal, transaditus, combined posterior tympanotomy and endomeatal, modified Veria, canal wall down approaches, and endoscopically assisted technique.

CONCLUSION

This review suggested that there are numerous distinct round window approaches, providing alternatives when the round window is inaccessible through the standard facial recess.

Minimally Invasive Cochlear Implantation Assisted by Intraoperative CT Scan Combined to Neuronavigation

OBJECTIVE

The objective of this work was to study the feasibility of minimally invasive cochlear implantation under intraoperative computerized tomography-scan coupled to navigation.

MATERIALS AND METHODS

Five human resin temporal bones (two adults and three children) were used. Initially, a temporal bone imaging was obtained by the intraoperative CT-scan coupled to the navigation (O-ARM). The navigation-assisted drilling began at the mastoid surface creating a conical tunnel (4-2 mm in diameter) through the facial recess and down to the round window. A cochleostomy was performed based on the navigation. A sham electrode array was inserted in the drilled tunnel and into the cochlea.Postoperative CT-scan and dissection were performed to evaluate the trajectory, and possible injury to the external auditory canal, ossicles, or facial nerve.

RESULTS

The mean duration of the procedure was 24.4 ± 3.79 minutes (range, 15-35). Cochleostomy was possible in all cases without injury to other structures. The sham array was inside the cochlea in all cases. The mean distance between the drilled canal and the mastoid portion of the facial nerve was 1.2 ± 0.07 mm (range, 1.08-1.38). The mean tracking error was 0.6 ± 0.26 mm (range, 0.20-0.72) at the entry point, 0.6 ± 0.33 mm (range, 0.2-1.02) at the facial nerve and 0.4 ± 0.07 mm (range, 0.36-0.51) at the cochleostomy.

CONCLUSION

Cochlear implantation through a minimally invasive approach assisted by intraoperative imaging combined with navigation was feasible in operating room environment and experimental conditions.

Simultaneous bilateral cochlear implantation under local anaesthesia in a visually impaired adult with profound sensorineural deafness: A case report

Objective: The National Institute of Clinical Excellence recommends that adult patients with severe to profound deafness are eligible for simultaneous bilateral cochlear implantation if they are blind or have other disabilities increasing their reliance on auditory stimuli. Cochlear implant (CI) surgery is routinely performed under general anaesthesia (GA), precluding patients who have higher risk associated with GA. Recent literature describes the safety and efficacy of performing unilateral CI surgery under local anaesthesia (LA). We report the first simultaneous bilateral CI under LA in the UK in an adult patient with profound sensorineural deafness and visual impairment.Case study: A 46-year-old gentleman, registered blind, presented with a 20-year history of bilateral progressive hearing loss. He was assessed as unfit for surgery under GA due to significant cardiac comorbidities. We performed simultaneous bilateral CI surgery under LA on the patient; he was discharged home the following day. Postoperative free field audiometry showed a significant improvement; speech discrimination using Bamford, Kowal and Bench sentences presented in quiet, increased from 0% pre-operatively to 100% four months post-operatively.Conclusion: Simultaneous bilateral CI surgery under LA is a safe and feasible procedure for eligible patients who may otherwise have been denied surgery due to their GA risk.

Evaluation of Subtotal Petrosectomy Technique in Difficult Cases of Cochlear Implantation

OBJECTIVES

To assess the validity of the subtotal petrosectomy (STP) technique in problematic cases of cochlear implant (CI) surgery, and review indications, outcomes, and related controversies.

STUDY DESIGN

This is a retrospective review of data from a private quaternary referral center of otology and skull base surgery.

PATIENTS AND METHODS

A review of patients who underwent CI with STP (STP-CI) as the leading approach was performed. Demographics, indications, surgical details, and main outcomes were evaluated. The surgeries performed were usually single-stage procedures encompassing a comprehensive mastoidectomy, blind sac closure of the external auditory canal (EAC), and mastoid obliteration with autologous fat.

RESULTS

A total of 107 cases were included. Mean follow-up was 7.1 years (range 1-13 years). The most frequent indication for STP-CI was chronic otitis media with/without cholesteatoma (32.7%), followed by open mastoid cavity (26.1%), and cochlear ossification (17.7%). Other difficult conditions where STP facilitates successful implantation include inner-ear malformations, temporal-bone trauma, unfavorable anatomic conditions, and revision surgery. A planned staged procedure was performed in 3 cases. The rate of major complications was 5.6% (n = 6). Three patients developed postauricular wound dehiscence which eventually resulted in device extrusion. No cases of recurrent/entrapped cholesteatoma, EAC breakdown, or meningitis were encountered. This is the largest single-center series of STP-CI reported in the literature.

CONCLUSIONS

When CI is intended in technically challenging cases or associated with a high risk of complications, STP is effective and reliable. Safe implantation and excellent long-term outcomes can be achieved provided surgical steps are properly followed. Single-stage procedures can be performed in most cases, even when there is active middle-ear disease.

Endoscopic-Assisted Cochlear Implantation in Children with Malformed Ears

OBJECTIVE

Complex middle and inner ear malformations are considered an important limitation for cochlear implant (CI) with traditional microscopic techniques. The aim of the present study is to describe the results of the endoscopic-assisted CI procedure in children with malformed ears.

STUDY DESIGN

Case series with chart review of consecutive patients.

SETTING

Two tertiary referral centers: University Hospital of Verona and University Hospital of Modena, Italy.

SUBJECTS AND METHODS

In total, 25 children underwent endoscopic-assisted cochlear implantation between January 2013 and January 2018. The audiologic and neuroradiologic assessment showed profound hearing loss and malformation of the middle and inner ear in all children. A complete review of anatomic features, surgical results, and audiologic outcomes was performed. The surgical technique is described step-by-step, and the outcomes are detailed.

RESULTS

All patients (mean age, 3.6 years; range, 2.8-9 years) underwent a transattical/endoscopic-assisted CI procedure. All children showed varying degrees of auditory benefit, as measured by routine audiometry, speech perception tests, and Categories of Auditory Performance scores (mean, 6). No immediate or late postoperative complications were noted.

CONCLUSION

The endoscopic-assisted approach proved to be successful in cochlear implantation. The direct visualization and magnification allow (1) exploration of the tympanic cavity; (2) confirmation of all anatomic features, with strict control of the course of the facial nerve, round window area, and inner ear; and (3) performance of the cochleostomy with adequate insertion of the array.

Systematic Review on Surgical Outcomes and Hearing Preservation for Cochlear Implantation in Children and Adults

OBJECTIVE

The mastoidectomy with facial recess approach (MFRA) is considered the reference standard for cochlear implantation. The suprameatal approach (SMA) was developed more recently and does not require mastoidectomy, which could influence postoperative outcomes. We aim to identify the optimal operative approach for cochlear implantation based on postoperative complications and hearing preservation in children and adults.

DATA SOURCES

PubMed, EMBASE, Scopus, and Google Scholar.

REVIEW METHODS

Studies comparing MFRA and SMA in children and adults were eligible for inclusion. Original reports with moderate relevance and validity were included. Relevance and validity were assessed with a self-modified critical appraisal tool. This review was reported in accordance to PRISMA guidelines.

RESULTS

We retrieved 294 citations. Only retrospective nonrandomized studies were identified (level III evidence). Six articles were selected for full-text inclusion and 4 articles for data extraction. No article found a significant difference between MFRA and SMA with respect to postoperative complications in children and adults. One study found a significantly (P < .023) higher pediatric MFRA mastoiditis rate; however, meta-analysis did not indicate an overall effect. Hearing preservation was reported only in adults, and outcomes between techniques did not differ.

CONCLUSION

No evidence was noted for lower complication rates or improved hearing preservation between the MFRA and SMA for cochlear implantation in children and adults. Pediatric data were available for children implanted above the age of 24 months only. Level I evidence is needed to resolve the uncertainty regarding differences in postoperative outcomes of pediatric and adult MFRA and SMA.

Subtotal Petrosectomy for Cochlear Implantation

Objectives:

The purpose of this study was to review the indications for subtotal petrosectomy for cochlear implantation, report our management of complications, as well as review those technical factors that are critical for successful implantation.

Methods:

Patients (n = 104) that underwent subtotal petrosectomy with closure of the external auditory canal and obliteration of the cavity with abdominal fat in combination with cochlear implantation were analyzed.

Results:

The most frequent indication for subtotal petrosectomy was the existence of a previous canal wall down technique. Postoperative complications occurred in 13 patients (11.83%). Extrusion of the device took place in 5 cases (4.55%).

Conclusions:

Subtotal petrosectomy in cochlear implantation permits obtaining a cavity isolated from the external environment, and when needed, it improves the access and visibility during the surgical procedure. Subtotal petrosectomy is a safe technique, with a low rate of complications.

Retrospective complication rate comparison between surgical techniques in paediatric cochlear implantation

OBJECTIVE

To compare paediatric complication occurrence between the Mastoidectomy with Posterior Tympanotomy and the SupraMeatal Approach for cochlear implantation.

DESIGN

Retrospective cohort study.

SETTING

Children receiving a cochlear implant before 5 years of age between 1996 and 2014 in our tertiary center.

PARTICIPANTS

A total of 144 patients receiving a cochlear implant (121 by Mastoidectomy with Posterior Tympanotomy and 23 by SupraMeatal Approach) operated on 165 ears (129 and 39 respectively).

MAIN OUTCOME MEASURES

The severity (minor or major) using Cohen and Hoffman criteria and time of occurrence of complications (intraoperative, early postoperative or late postoperative) were identified. Intraoperative surgical challenges were correlated to complication occurrence.

RESULTS

The mean age at implantation was 2.13 ± 1.14 years old. Patients operated by the SupraMeatal Approach (1.27 ± 0.69 years old) were significantly (P < .001) younger than those receiving a cochlear implant by Mastoidectomy with Posterior Tympanotomy Approach (2.40 ± 1.12). Most complications were minor (Mastoidectomy with Posterior Tympanotomy Approach: 64.0%; SupraMeatal Approach: 73.1%) and occurred early postoperatively (Mastoidectomy with Posterior Tympanotomy Approach: 61.5%; SupraMeatal Approach: 76.9%). More overall complications occurred in SupraMeatal compared to Mastoidectomy with Posterior Tympanotomy Approach cases (61.5% versus 20.6%; P < .001). Younger SupraMeatal Approach cohort patients (6 - 12 and 18 - 24 months; P < .008 and P = .016) most often developed these complications. When looking at specific complications, more infectious complications occurred in patients receiving a cochlear implant through the SupraMeatal Approach (P < .05). Logistic regression showed that the surgical technique and not the age at implantation was responsible for the documented complications. No relationship between complications and intraoperative difficulties was identified.

CONCLUSION

In our institution, cochlear implantation in young patients through the SupraMeatal Approach resulted in significantly more (infectious) complications than those operated through the Mastoidectomy with Posterior Tympanotomy Approach. Outcomes from our institution recommends using the Mastoidectomy with Posterior Tympanotomy Approach when opting for a cochlear implant surgical technique in young children who are more prone to develop infectious complications.