How Cochlear Implant Rehabilitation Impacts the Therapeutic Strategy for Vestibular Schwannoma
Round 1
Reviewer 1 Report
Reviewing article Audiol res-2108347-Review paper
How cochlear implant rehabilitation impacts on the therapeutic
strategy of vestibular schwannoma
I have read with attention this review paper about CI in vestibular schwannomas therapy strategy
This study was conducted through 16 retained publications (Pub Med, Scopus). The authors focus in this work on the interest in sporadic VS of small tumors Koos grade I (< 10mm) with residual hearing and favorable per operatory observation and electrophysiological results ( Cochlear nerve action potential (CNAP) are mentioned as more reliable than BERA)
The feasibility is discussed either per operatively or post operative (a delay < 8 month in this last condition is advised or as soon as possible).
These surgical results are discussed in face of non surgical treatments and most conservative treatments as stereotactic gamma knife Radiosurgery (risk of further functional loses in time is suggested)
Although the overall work is clear and well presented for the different situations ( (sporadic VS, Neurofibromatosis type 2, intralabyrinthine Schwannomas) some concerns need to be further answered
Minor remarks
Line 59. In material and Methods: the number of 187 publications initially recruited and mentioned in the text is different from the number of 137 mentioned in the flowchart ( typing error?)(please homogenize)
Line 162 the sentence begins with “90% of the patients”: It should be “Ninety percent of the patients”… since usually a number beginning a sentence must be written in letters
Line 59 . In the same way the number “187” beginning the sentence should be replaced by “One hundred and Seven..”
Discussion. line187 typing error. It should be “1.02 cm3”
Line 195. typing error: “unerwent” should be replaced by “underwent”
Line 203: “Four to six of all VS” is not clear and should be completed.
Line 257 this sentence should be rephrased the word “Who “ seems to be missing between the word ”of patients” and “ underwent ….”
Other remarks
The current guidelines for Review paper and meta-analysis methodology should refer more precisely to PRISMA etc..
A Possible ref.: Liberati A et a. in lPlos one .The PRISMA Statement for Reporting Systematic Reviews
and Meta-Analyses of Studies That Evaluate Health Care Interventions: Explanation and Elaboration
Alessandro Liberati1,2*, Douglas G. Altman3, Jennifer Tetzlaff4, Cynthia Mulrow5, Peter C. Gøtzsche6, John P. A. Ioannidis7, Mike Clarke8,9, P. J. Devereaux10, Jos Kleijnen11,12, David Moher4,13
Other works from Egger 2020 or Shim and Kim 2019 could be cited
The results , discussion and conclusion should be materialized by a clear decision tree or presented as a flow-chart. This could improve the paper.
Overall this paper gives a good idea of the state of the art in matter of CI in VS but could be improved.
Author Response
Dear reviewer,I have appreciated your suggestions.
1) Minor remarks have been revised;
2) This review was designed as a narrative review so PRISMA guidelines have been followed in a less strictly manner; citing PRISMA statement could be not appropriate;
3) I’ve been unable to find relevant result searching the works from Egger, Shim and Kim;
In order to provide a guide to the results section i have included a schematic summary table with all papers used in the "discussion" section and proposed a possible decisional algorithm in the "conclusion" section;
Best regards
Author Response File: 
Author Response.docx
Reviewer 2 Report
This study is a systematic review of the use of cochlear implantation (CI) in patients diagnosed with vestibular schwannoma (VS) who underwent simultaneous or sequential cochlear implantation surgery. Overall, this review is not innovative, prior reviews have been published, however, it does include recent published data. The review is well organized and with clear objectives. The authors specify with details the inclusion criteria used. Data analyzed in this review could not be pooled due to the lack of standardize outcome measures between studies. Importantly, there was not a clinical appraisal of the quality of the included primary studies and their results. Authors should consider performing this appraisal if appropriate; if not, they should explain why it could not be performed.
The title of the manuscript is misleading since it suggests that it will discuss how the results of CI outcomes have changed/impacted the therapeutic strategies in patients diagnosed with VS, but the actual discussion is based only on the reviewed manuscripts. If the authors believe that there has been a change regarding selection criteria for CI surgery in patients with VS, please describe it. Is this something that has been mainly impacted your institution, region, or continent?
Authors should consider proposing a possible standard protocol on how to assess outcome measures of CI in patients diagnosed with VS, including an appropriate post CI surgery follow up timeline, since most available data is difficult to pool an analyze. It seems that the most difficult parameter to comply with is a long-term follow.
Grammar typos to address:
Line 22 - Add the acronym “VS” after Vestibular schwannoma and continue using the acronym within the rest of the manuscript.
Line 23 - Comma after “decades”
Line 81 - please define HPS and use its acronym in the rest of the manuscript after it is defined.
Line 140 , 143, 172, 186 - change IC for CI
Line 190-193 sentence is repeated in the previous paragraph
Line 195 - Change word “unerwent” to “underwent”
Line 257 - make patient plural to “patientS” and add “who” before underwent
Line 285 - add “the” before literature
Author Response
Dear reviewer,I have appreciated your suggestions.
1) Minor remarks have been revised;
2) We introduced a table with a possible decisional algorithm regarding CI indication that reflects the statement of the title;
Best regards
Author Response File: Author Response.docx
Reviewer 3 Report
This manuscript is puzzling for many reasons: 1/ It is more or less an advocacy for cochlear implantation (CI) and vestibular schwannoma surgery (VS) for small VS, whether it is performed simultaneously or delayed, than a clear-cut demonstration of its usefulness; 2/ it seems that other manuscripts should have been included in the study considering the selection criteria; 3/ Tabulations of the results of different reported studies should be done to be able to compare them ; 4/ The conclusion that CI would be indicated when hearing is already altered small VS is not supported by the results of different studies which demonstrated that the better the pre-operative hearing level, the better the post-op CI performance.
Abstract line 13: 2. Methods line 60: Why more precise information in the former than inn the latter ?
1. Introduction lines29-39: The authors could refer to a longitudinal study over 12 years of sporadic VS (Jia et al, Laryngoscope 2021)
1. Introduction lines 42-45: High rate of normal post-op facial nerve function can be achieved by near/subtotal removal of large VS under FN monitoring (see Bernardeschi et al, J Neurosurg, 2018; Daoudi et al, Acta Neurochir, 2020; Elsayed et al, Acta Neurochir, 2021)
3. Results lines 69-72: Functional preservation of either facial and cochlear is dependant on mainly the adhesion of the tumour on the nerves whatever VS volume (see Esquia-Medina et al, OtolNeurotol 2009; Bernat et al, OtolNeurotol 2010)
3. Results lines 92-97: It can be speculated that the VS volume was different whether it was removed through a retrosigmoid or middle cranial fossa approach ? indicate VS volume for both groups ?
3. Results lines 100-104: add a table with the Arnoldner's classification.
3. Results lines 127-133: Reference for FDA study is lacking. A prospective study on 155 patients was reported by Marx et al (Clin Otolaryngology 2021).
3. Results lines 140-189: Rather than giving the results could be tabulated as done in a study which has not been included (Nguyen et al, Laryngoscope 2020) as well as Lassaletta et al paper(Eur Arch Otorhinolaryngol, 2016).
3.Results line 183: Define "audibility"
3. Results lines 194-196 and Lines 299-303: The same is quoted twice for the same results. The former sentence could bee omitted.
3. Results lines 190-201: Reference to Stefan Plonkte's works should be quoted.
3.Results lines210-213: Add Chemotherapy (bevacizumad) for NF2- related VS management (Ploktin et al, OtolNeurotol 2012)
3. Results lines 217-242: All the reported studies on NF2-related VS management could be tabulated as for sporadic VS and the main issue given in the text.
3. Results lines 243-268: This chapter should be individualised as the last chapter 3.5 (post-op imaging), since it applies to all kinds of tumors, sporadic and NF2-related VS and sporadic and NF2-related intralabyrinthine schwannomas.
3. Results lines277-282: Does this sentence refer to only NF2-related VS but to sporadic VS as well ? If so it may be better to write another small chapter 3.6 on pronostic factors for hearing preservation. The classification of hearing loss should be added on a separate table .
3. Results chapter 3.4: Reference to Stefan Plonkte works should be quoted, and management of intravestibular schwannomas and CI is missing (Jia et al, OtolNeurotol 2019)
4. Conclusions: The authors should provide some guidelines for CI and VS management or a decisional algorithm ?
4. Conclusions lines 315-318: An ABI could proposed simultaneously to the large VS removal.
Author Response
Dear Collegue,
I appreciated your suggestions.
1) Minor remarks have been revised;
2) Added in the discussion the advised papers (Jia 2019, Marx 2021, Plontke 2021, Plotkin 2012).
3) Added summary table to resume the main outcomes of the selected studies and a possible decisional algorithm in the final section.
Best regards
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
This study is a systematic review of the use of cochlear implantation (CI) in patients diagnosed with vestibular schwannoma (VS) who underwent simultaneous or sequential cochlear implantation surgery. Overall, the review is well organized and with clear objectives. The authors specify with details the inclusion criteria used. Data analyzed in this review could not be pooled due to the lack of standardize outcome measures between studies. Additionally, the authors have made appropriate changes to most of my concerns, but I still believe that this review is not innovative, however, its value is centered on the recent published data that is included, in addition to a proposed table of their in-house recommendations for treatment of VS (Table 3). However, table 3 only states the recommendation on surgery versus observation depending on the size of the tumor and growth vs no growth. I would like to see a discussion regarding when the authors recommend cochlear implantation to these patients and what is the minimum interval to cochlear implantation in those patients that underwent HPS and ended up needed cochlear implantation and the potential limitations the authors have found to achieve this, if possible.
Author Response
Dear reviewer,
I added a brief comment at the end of the "Discussion" Section which provides the recommendations for CI in the different gruops of patients.
I hope that this comment will clarify your doubts.
Best regards
Author Response File: Author Response.docx
Reviewer 3 Report
Line 27: "BIAS" should be written in minuscule
Otherwise the manuscript has been adequately revised
Author Response
Dear reviewer,
I have rectified the line 27.
I have also added a brief comment about the possible recommendation for CI in the different gruops of patients.
Best regards
Author Response File: Author Response.docx
