Surgical and Radiologic Anatomy

, Volume 41, Issue 7, pp 853–857 | Cite as

Anatomic variations of the round window niche: radiological study and related endoscopic anatomy

  • Pietro CanziEmail author
  • Irene Avato
  • Marco Manfrin
  • Anna Maria Simoncelli
  • Marianna Magnetto
  • Elisabetta Rebecchi
  • Carmine Tinelli
  • Marinella Neri
  • Millo Achille Beltrame
  • Marco Benazzo
Anatomic Variations



In the last decades, literature has shown an increasing interest in round windows (RW) anatomy due to its pivotal role in deafness surgery. The high variability of this anatomical region, with particular regard to the round windows niche (RWN), has been studied by several authors through different methods of investigation. The aim of the present research was to radiologically examine the morphological variability of the RWN and to link the imaging findings to the endoscopic view.


High-resolution CT scans of 300 temporal bones without neuro-otological pathologies were retrospectively reviewed by 2 neuroradiologist and 1 ENT surgeon who independently evaluated the RWN morphological variations. To link the radiological to the endoscopic data, 45 cadaveric human temporal bones were submitted to a radiological evaluation and to an otoendoscopy conducted through a posterior tympanotomy approach.


Three variants of the RWN were detected on coronal CT scan reconstructions: 155 “cylindrical-type”, 97 “j-type” and 48 “truncated cone-type”. For each radiological type the endoscopic findings showed a specific endoscopic position of the RW chamber, which results in different degrees of RW membrane visibility when analysed through a posterior tympanotomy approach.


To the best of our knowledge, this is the first description of the above-mentioned RWN radiological variations supported by endoscopic data. This study suggests an additional anatomical evaluation that could be useful to predict the RW membrane visibility through a posterior tympanotomy approach. Further studies are required to support the clinical implications of our observations.


Round window niche Anatomic variation Cochlear implant Endoscopic anatomy Radiological anatomy Middle ear 


Author contributions

PC: Project development, data analysis, manuscript writing. IA: data analysis, manuscript writing. MM: data analysis. AS: data collection, data analysis. MM: data analysis, manuscript editing. ER: data collection, data analysis. CT: data analysis. MN: data collection, data analysis. MAB: project development. MB: project development.


All the authors certify that they receive no financial support or funding for this work.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical standards

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

For this type of study, formal consent is not required (retrospective study).

Human/animal rights statement

This article does not contain any studies with animal participants performed by any of the authors.


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Copyright information

© Springer-Verlag France SAS, part of Springer Nature 2019

Authors and Affiliations

  • Pietro Canzi
    • 1
    Email author
  • Irene Avato
    • 1
    • 2
  • Marco Manfrin
    • 1
  • Anna Maria Simoncelli
    • 3
  • Marianna Magnetto
    • 1
  • Elisabetta Rebecchi
    • 1
  • Carmine Tinelli
    • 4
  • Marinella Neri
    • 5
  • Millo Achille Beltrame
    • 1
  • Marco Benazzo
    • 1
  1. 1.Department of OtorhinolaryngologyUniversity of Pavia, IRCCS Policlinico San Matteo FoundationPaviaItaly
  2. 2.Experimental MedicineUniversity of PaviaPaviaItaly
  3. 3.Department of Diagnostic Radiology and Interventional Radiology and NeuroradiologyUniversity of Pavia, IRCCS Policlinico San Matteo FoundationPaviaItaly
  4. 4.Biometric ServiceUniversity of Pavia, IRCCS Policlinico San Matteo FoundationPaviaItaly
  5. 5.Department of RadiologySanta Maria del Carmine HospitalRoveretoItaly

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