Endoscopic cochlear implantation: Call for caution

Endoscopic-Assisted Cochlear Implantation in Far Advanced Otosclerosis

OBJECTIVES

To evaluate the effectiveness of cochlear implantation (CI) in case of far advanced otosclerosis and to evaluate the value of using intraoperative otoendoscopy to facilitate the identification of the round window membrane and the scala tympani without the need to remove the posterior canal wall or to perform a subtotal petrosectomy.

STUDY DESIGN

Retrospective case-series study.

SETTING

Tertiary academic CI center.

PATIENTS AND METHODS

This study was conducted on patients with far advanced otosclerosis who underwent endoscopic-assisted CI between January 2010 and June 2020 at the same CI center. The minimum follow-up period was 2 years after surgery.

RESULTS

Fourteen patients were included in the study. Ten patients had undergone a previous stapedotomy. Electrode insertion in the scala tympani was successfully accomplished in all cases included in the study. There was a statistically significant improvement in pure-tone average and speech discrimination scores in all cases of the study group (p < 0.0001). There were no statistically significant differences in postoperative pure-tone average or speech discrimination scores between cases with and without cochlear ossification or between cases with and without a previous stapedotomy (p > 0.05).

CONCLUSION

Endoscopic-assisted CI is an effective option for hearing restoration in patients with far advanced otosclerosis. Otoendoscopy can facilitate visualization and access to the scala tympani without the need to remove the posterior canal wall or to perform a subtotal petrosectomy.

Endoscope-Assisted Cochlear Implantation in Atretic Round Window

Different techniques have been proposed for cochlear implant (CI) from its conventional transmastoid posterior tympanotomy approach. Endoscopy role in the otologic field is still relatively new, but it provides a better surgical view with improved image clarity, especially in the challenging anatomical visualization of the critical structures in CI surgery. A 3-year-old girl with bilateral progressive profound hearing loss was scheduled for left cochlear implant surgery. The pre-operative high-resolution computed tomography (HRCT) of the temporal bone and magnetic resonance (MR) of internal acoustic meatus reported no significant abnormality of the middle and inner ears structures bilaterally. The standard left postauricular cortical mastoidectomy and posterior tympanotomy were performed. However, the microscopic view could not visualize the round window (RW) niche despite a widened extended posterior tympanotomy and surgical field manipulation. Transfacial recess endoscopic examination was done and was able to identify the possibly atretic RW. With endoscopic guidance, CI electrodes were inserted via cochleostomy, and intraoperative impedance measurement and neural response telemetry were obtained both during surgery and the postoperative phase. No intra- and postoperative complications were observed in this case. Following activation, the CI was functioning well. In conclusion, atretic RW is a rare anomaly found intraoperatively during CI surgery. Endoscope-assisted electrode insertion offers excellent visualization of targeted middle ear structures, especially in limited or abnormal anatomy of RW, which could minimize the risk of surgical complications.

The role of the endoscope in cochlear implantation. A systematic review

OBJECTIVE

To review the role of the endoscope in cochlear implantation (CI).

METHODS

MEDLINE, ScienceDirect, Google Scholar and the Cochrane Library databases as well as other sources were searched by two independent reviewers. Studies including patients undergoing either exclusively endoscopic or endoscopic ally assisted CI were eligible for inclusion. Endoscopic CI approaches and postoperative complications were the primary outcomes. Secondary endpoints included the degree of round window (RW) microscopic visualization according to St Thomas' Hospital classification as well as type of cochleostomy for electrode insertion in the scala tympani (ST).

RESULTS

Fourteen studies met the inclusion criteria comprising 191 endoscopic or endoscopically assisted CI cases. The endoscope was used for better visualization of the RW across all included studies, facilitated the insertion of the electrode in the ST and spared a mastoidectomy in a number of cases. No facial nerve palsy was reported in any of the studies. The most common complication was external auditory canal/ tympanic membrane tear followed by chorda tympani injury.

CONCLUSION

The microscopic CI approach is still the gold standard. The endoscope facilitates the recognition of the RW area and leads to successful and safe implantation particularly in difficult anatomical scenarios, ear malformations and advanced otosclerosis. Endoscopically assisted CI procedures offer the opportunity to avoid a posterior tympanotomy and reduce the risk of facial nerve injury. To date, the lack of long term data does not permit the widespread adoption of completely endoscopic CI procedures without a mastoidectomy.

Endoscope-assisted Partial Cochlectomy for Intracochlear Schwannoma With Simultaneous Cochlear Implantation: A Case Report

INTRODUCTION

Intralabyrinthine schwannomas are a small subset of vestibular schwannomas which originate within the labyrinthine structures. Management typically consists of watch-and-wait strategies given that surgical intervention will sacrifice hearing. Endoscopic resection of primary intracochlear schwannoma with simultaneous cochlear implantation for a patient with progressive hearing loss and debilitating tinnitus is described.

PATIENT

A 56-year-old male presenting with asymmetric left sensorineural hearing loss (SNHL) was diagnosed with intracochlear schwannoma on MRI.

INTERVENTION

Surgery was indicated due to tumor growth on serial imaging, worsening SNHL, and severe tinnitus. Partial cochlectomy was performed via transcanal endoscopic approach. Cochlear implantation via mastoidectomy and posterior tympanotomy was simultaneously performed with a CI512 Contour Advanced implant (Cochlear, Sydney, Australia).

MAIN OUTCOME MEASURES

Post partial cochlectomy speech performance.

RESULTS

Preoperative audiometry showed left profound SNHL with 20% speech recognition score despite maximal amplification. Speech perception testing 5 months postoperatively demonstrated good unilateral discrimination when testing the implanted ear alone (BKB sentences 66%, CUNY sentences 79%), open-set comprehension, and excellent binaural performance.

CONCLUSION

The endoscope offers an additional viable approach to the otic capsule for the removal of intracochlear schwannoma and good audiologic outcomes can be achieved with simultaneous cochlear implantation even after partial cochlectomy.

Cochlear Implant Surgery: Endomeatal Approach versus Posterior Tympanotomy

The aim of the present study was to compare the posterior tympanotomy (PT) technique to the endomeatal approach. The endomeatal approach (EMA) for Cochlear Implant (CI) surgery was performed on 98 patients with procident lateral sinus or a small mastoid cavity, on 103 ears (Group A). Conventional mastoidectomy and PT was performed on the other 104 patients, on 107 ears (Group B). Data on all patients were then collected for the following: intra- and post-operative complications, Tinnitus Handicap Inventory (THI), Vertigo Symptom Scale (VSS), duration of surgery, and postoperative discomfort. The difference in the total number of major and minor complications between the case group and the control group was not statistically significant. There was a statistically significant difference in discomfort between the two groups using the Visual Analogue Scale (VAS), both immediately postsurgery (p = 0.02) and after one month (p = 0.04). The mean duration of surgery was 102 ± 29 min for EMA and 118 ± 15 min for the PT technique (p = 0.008). EMA is a faster technique resulting in reduced postoperative patient discomfort in comparison to the PT method. The experience of the surgeon as well as the correct choice of surgical technique are fundamental to successful outcomes for cochlear implant surgery.

Endoscopic visualisation of the round window during cochlear implantation

Background

Endoscopes provide a magnified view of the middle ear and visualisation of hidden areas. Otoendoscopes facilitate excellent visualisation of the round window niche during cochlear implantation.

Objective

To compare microscopic and endoscopic visualisation of the round window membrane during cochlear implantation in 20 patients.

Methods

Twenty patients who underwent cochlear implantation were included in the study. After maximum exposure of the round window, the accessibility of the round window membrane was graded according to the St Thomas Hospital classification, first by microscope and then by endoscope.

Results

With the use of the endoscope, visualisation of the round window membrane improved in all the patients as compared to the microscope. The electrode array was inserted via a round window or extended round window approach in all but two cases; the latter cases required bony cochleostomy because of unfavourable anatomy.

Conclusion

The main benefit of endoscope-assisted cochlear implantation is improved visibility of the round window region.

Endoscopic approach to the round window through posterior tympanotomy for cochlear implantation in children: A study on feasibility

OBJECTIVE

To demonstrate the feasibility of rigid endoscopy through posterior tympanotomy, which provides both a view of the round window and direction of the scala tympani in children.

METHODS

After a standard mini-invasive surgical approach with postauricular access and transmastoid posterior tympanotomy of 2 mm, a 0°, 1.9 mm diameter and 11 cm long endoscope is positioned in proximity of the upper part of the posterior tympanotomy to obtain a panoramic view of the inferior part of the medial wall of the tympanic cavity. Surgical complications and changes in hearing threshold were analyzed.

RESULTS

Eight children were submitted to cochlear implantation with endoscopic assistance through posterior tympanotomy. Complete visualization of the round window niche was possible in every ear. No complications related to the procedure were observed. Preoperative threshold was preserved in 9 of 10 ears.

CONCLUSIONS

Direct endoscopic view through the posterior tympanotomy allows visualization of the entire round window niche as well as the angle of introduction of the multi-electrode array along the direction of the scala tympani.

Endoscopic ear surgery

Objectives

This article reviews the advantages and disadvantages of endoscopic ear surgery (EES).

Method

Pubmed, Google and the Proquest Central Database at Kırıkkale University were queried using the keywords “endoscopic ear surgery”, “ear surgery” and “endoscopy” to identify the literature needed for the review.

Results

Endoscopes allow for enhanced surgical visualisation. The distal part of the apparatus is illuminated and contains lenses angled to allow a wider view of the operative area. Transcanal endoscopic techniques have transformed the external ear canal (EAC) into an operative gateway. The benefits EES can offer include wider views, enhanced imaging capabilities and increased magnification, and ways to see otherwise poorly visualisable portions of the middle ear. EES permits surgeons to operate using minimally invasive otological techniques. When compared with microscope-assisted surgery, endoscopic tympanoplasty has been shown to require a shorter operating time in some instances. There are a number of drawbacks to EES, however, which include the fact that it is a single-handed technique, that the light source may produce thermal injury and that visualisation using the endoscope is severely curtailed if bleeding is profuse.

Conclusion

EES is a safe and effective technique. The current literature supports the idea that the results achieved by endoscopic methods are usually comparably beneficial to results obtained using conventional microscopic methods.

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.

Endoscope-Assisted Cochlear Implantation

OBJECTIVES

Our aim was to present our endoscope-assisted cochlear implantation (CI) technique, in which the middle ear landmarks were identified through the facial recess exposure by using an endoscopic view without elevating the tympanic annulus. The secondary goal was to assess whether the situation of difficult surgical exposure could be predicted by evaluating preoperative axial computed tomography (CT) examinations.

METHODS

CT examinations and surgical outcomes of endoscope-assisted CI surgeries were analyzed.

RESULTS

A total of 179 CI operations performed in 27 adults (15.1%) and 152 children (84.9%) were retrospectively evaluated. It was found that in 14 cases (7.8%), endoscopic examination contributed substantially in identifying the round window (RW) membrane correctly. Endoscopic identification of the RW through the posterior tympanotomy enabled us to perform a straightforward surgery in all these cases, without the need for switching to a bony cochleostomy or alternative surgical techniques. The difficulty in the surgical exposure was predicted preoperatively by examining the axial CT scans in six of the 14 cases (42.8%) for which endoscopic assistance was necessary in order to identify the RW correctly.

CONCLUSION

The main benefit of endoscope-assisted CI is the improved visibility leading to a panoramic view of the RW region. The implementation of transfacial recess endoscopic examination into the conventional CI technique is helpful to avoid problems during surgical orientation. However, the difficulty in the surgical exposure of the RW cannot be reliably predicted by the subjective evaluation of preoperative CT scans and more studies are needed to obtain reliable criteria.