Implantation via the Round Window and Cochlear Hook Anatomy

  • Charles G. Wright
  • Peter S. Roland


The round window of the human cochlea shows significant anatomic variability, which can make its use as a portal for implant electrode insertion somewhat challenging. However, round window insertion is potentially less traumatic to inner ear structures than is electrode placement via a standard promontory cochleostomy. Round window insertion is now widely used in cases in which hearing preservation is the goal, and it is particularly well suited for placement of thin, straight electrode arrays intended to track the lateral wall of scala tympani.


Round window niche Round window membrane Implant insertion Cochlear hook 


  1. 1.
    Nomura Y. Otological significance of the round window. Adv Otorhinolaryngol. 1984;33:1–62.PubMedGoogle Scholar
  2. 2.
    Su WY, Marion MS, Hinojosa R, Matz GL. Anatomical measurements of the cochlear aqueduct, round window membrane, round window niche, and facial recess. Laryngoscope. 1982;92:483–6.CrossRefPubMedGoogle Scholar
  3. 3.
    Okuno H, Sando I. Anatomy of the round window: a histological study with a graphic reconstruction method. Acta Otolaryngol. 1988;106:55–63.CrossRefPubMedGoogle Scholar
  4. 4.
    Cervera-Paz FJ, Linthicum FH, Manrique MJ, Perez N. Morphometry of the human cochlear wall and implications for cochlear surgery. Acta Otolaryngol. 2004;124:1124–30.CrossRefPubMedGoogle Scholar
  5. 5.
    Roland PS, Wright CG, Isaacson B. Cochlear implant electrode insertion: the round window revisited. Laryngoscope. 2007;117:1397–402.CrossRefPubMedGoogle Scholar
  6. 6.
    Alzamil KS, Linthicum FH Jr. Extraneous round window membranes and plugs: possible effect on intratympanic therapy. Ann Otol Rhinol Laryngol. 2000;109:30–2.CrossRefPubMedGoogle Scholar
  7. 7.
    Stewart TJ, Belal A. Surgical anatomy and pathology of the round window. Clin Otolaryngol. 1981;6:45–62.CrossRefPubMedGoogle Scholar
  8. 8.
    Fujita T, Shin JE, Cunnane M, Fujita K, Henein S, Psaltis D, et al. Surgical anatomy of the human round window region: implications for cochlear endoscopy through the external auditory canal. Otol Neurotol. 2016;37:1189–94.CrossRefPubMedGoogle Scholar
  9. 9.
    Aslan A, Gunhan K, Eskiizmir G, Elhan A. Anatomic observations on variations of the round window niche and its relationship to the tympanic membrane. J Int Adv Otol. 2006;2:52–7.Google Scholar
  10. 10.
    Souter MA, Briggs RJS, Wright CG, Roland PS. Round window insertion of precurved perimodiolar electrode arrays: how successful is it? Otol Neurotol. 2011;32:58–63.CrossRefPubMedGoogle Scholar
  11. 11.
    Franz BKH, Clark GM, Bloom DM. Surgical anatomy of the round window with special reference to cochlear implantation. J Laryngol Otol. 1987;101:97–102.CrossRefPubMedGoogle Scholar
  12. 12.
    Ishiyama A, Doherty J, Ishiyama G, Quesnel AM, Lopez I, Linthicum FH. Post hybrid cochlear implant hearing loss and endolymphatic hydrops. Otol Neurotol. 2016;37:1516–21.CrossRefPubMedPubMedCentralGoogle Scholar
  13. 13.
    Paprocki A, Biskup K, Kozlowska K, Kuniszyk A, Bien D, Niemczyk K. The topographical anatomy of the round window and related structures for the purpose of cochlear implant surgery. Folia Morph (Warsz). 2004;63:309–12.Google Scholar
  14. 14.
    Adunka O, Unkelbach MH, Mack M, Hambek M, Gstoettner W, Kiefer J. Cochlear implantation via the round window membrane minimizes trauma to cochlear structures: a histologically controlled insertion study. Acta Otolaryngol. 2004;124:807–12.CrossRefPubMedGoogle Scholar
  15. 15.
    Richard C, Fayad JN, Doherty J, Linthicum FH Jr. Round window versus cochleostomy technique in cochlear implantation: histological findings. Otol Neurotol. 2012;33(7):1181.CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    Proctor B, Bollobas B, Niparko JK. Anatomy of the round window niche. Ann Otol Rhinol Laryngol. 1986;95:444–6.CrossRefPubMedGoogle Scholar
  17. 17.
    Tóth M, Alpár A, Patonay L, Oláh I. Development and surgical anatomy of the round window niche. Ann Anat. 2006;188:93–101.CrossRefPubMedGoogle Scholar
  18. 18.
    Marchioni D, Alicandri-Ciufelli M, Pothier DD, Rubini A, Presutti L. The round window region and contiguous areas: endoscopic anatomy and surgical implications. Eur Arch Otorhinolaryngol. 2015;272:1103–12.CrossRefPubMedGoogle Scholar
  19. 19.
    Marchioni D, Soloperto D, Colleselli E, Tatti MF, Patel N, Jufas N. Round window chamber and fustis: endoscopic anatomy and surgical implications. Surg Radiol Anat. 2016;38:1013–9.CrossRefPubMedGoogle Scholar
  20. 20.
    Bonali M, Anschuetz L, Fermi M, Villari D, Mariani GA, Manzoli L, et al. The variants of the retro- and hypotympanum: an endoscopic anatomical study. Eur Arch Otorhinolaryngol. 2017;274:2141–8.CrossRefPubMedGoogle Scholar
  21. 21.
    Anson BJ, Bast TH. The development of the otic capsule in the region of the cochlear fenestra. Ann Otol Rhinol Laryngol. 1953;62:1083–116.CrossRefPubMedGoogle Scholar
  22. 22.
    Wright CG, Halama AR, Meyerhoff WL. Ototoxicity of an ototopical preparation in a primate. Am J Otol. 1987;8:56–60.PubMedGoogle Scholar
  23. 23.
    Schachern PA, Paparella MM, Duvall AJ III, Choo YB. The human round window membrane. An electron microscopic study. Arch Otolaryngol. 1984;110:15–21.CrossRefPubMedGoogle Scholar

Suggested Reading

  1. Atturo F, Barbara M, Rask-Andersen H. Is the human round window really round? An anatomic study with surgical implications. Otol Neurotol. 2014;35:1354–60.CrossRefPubMedGoogle Scholar
  2. Donaldson JA. Fossula of the cochlear fenestra. Arch Otolaryngol. 1968;88:32–8.CrossRefGoogle Scholar
  3. Havenith S, Lammers MJW, Tange RA, Trabalzini F, della Volpe A, van der Heijden GJ, et al. Hearing preservation surgery: cochleostomy or round window approach? A systematic review. Otol Neurotol. 2013;34:667–74.CrossRefPubMedGoogle Scholar
  4. Li PMMC, Wang H, Northrop C, Merchant SN, Nadol JB Jr. Anatomy of the round window and hook region of the cochlea with implications for cochlear implantation and other endocochlear surgical procedures. Otol Neurotol. 2007;28:641–8.CrossRefPubMedPubMedCentralGoogle Scholar
  5. Proctor B. Surgical anatomy of the posterior tympanum. Ann Otol Rhinol Laryngol. 1969;78:1026–40.CrossRefPubMedGoogle Scholar
  6. Singla A, Sahni D, Gupta AK, Loukas M, Aggarwal A. Surgical anatomy of round window and its implications for cochlear implantation. Clin Anat. 2014;27:331–6.CrossRefPubMedGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Charles G. Wright
    • 1
  • Peter S. Roland
    • 1
  1. 1.Department of Otolaryngology-Head and Neck SurgeryUniversity of Texas Southwestern Medical CenterDallasUSA

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