A novel omnidirectional tin-alloyed ring retractor for craniotomy in neurosurgery: technical note


In neurosurgical operations, proper craniotomy using retractors is necessary. Various surgical instruments are used for this purpose, including standard retractors and multipurpose head frame retractor systems. However, the conventional multipurpose head frame system is often not optimal for use in some craniotomies and postures because of its size and complexity of setting. We have invented a new omnidirectional tin-alloyed (ODT) ring retractor for craniotomy with malleability and shape memory characteristics to resolve these issues. It is principally elliptical in shape, approximately 30 × 20 cm in diameter, and sufficiently firm. Accordingly, this ODT ring can retract the surgical field in all directions. Here, we report our experiences of 281 neurosurgical craniotomies using this ODT ring retractor system in various craniotomy sites and postures. Our novel ODT ring retractor is useful because of its low profile, multidirectional retractability, and less obstructiveness with its malleability. It could be used with pediatric patients where strong traction is not desirable.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  1. 1.

    Beuriat PA, Jacquesson T, Jouanneau E, Berhouma M (2016) Headholders’ - complications in neurosurgery: a review of the literature and recommendations for its use. Neurochirurgie 62:289–294. https://doi.org/10.1016/j.neuchi.2016.09.005

    Article  PubMed  Google Scholar 

  2. 2.

    Choudhari KA, Pherwani AA (2007) Sudden visual loss due to posterior ischemic optic neuropathy following craniotomy for a ruptured intracranial aneurysm. Neurol India 55:163–165

    Article  Google Scholar 

  3. 3.

    de Andrade Júnior FC, de Andrade FC, de Araujo Filho CM, Carcagnolo Filho J (1998) Dysfunction of the temporalis muscle after pterional craniotomy for intracranial aneurysms. Comparative, prospective and randomized study of one flap versus two flaps dieresis. Arq Neuropsiquiatr 56:200–205

    Article  Google Scholar 

  4. 4.

    Kadri PA, Al-Mefty O (2004) The anatomical basis for surgical preservation of temporal muscle. J Neurosurg 100:517–522. https://doi.org/10.3171/jns.2004.100.3.0517

    Article  PubMed  Google Scholar 

  5. 5.

    Kang S, Yang Y, Kim T, Kim J (1997) Sudden unilateral blindness after intracranial aneurysm surgery. Acta Neurochir 139:221–226

    Article  CAS  Google Scholar 

  6. 6.

    Kawaguchi M, Sakamoto T, Furuya H, Ohnishi H, Karasawa J (1996) Pseudoankylosis of the mandible after supratentorial craniotomy. Anesth Analg 83:731–734

    Article  CAS  Google Scholar 

  7. 7.

    Moteki Y, Okada Y, Inoue T, Sato S, Kuwamoto K, Shima S, Niimi Y (2018) The availability of a tin-alloyed omnidirectional retractor-supporting ring for ventriculoperitoneal shunt laparotomy. World Neurosurg 109:110–114. https://doi.org/10.1016/j.wneu.2017.09.085

    Article  PubMed  Google Scholar 

  8. 8.

    Okada T, Ishikawa T, Nishimura H, Suzuki A (2012) How much pressure is applied on the eye balls during craniotomy?: measurement with FlexiForce contact surface force sensor. No Shinkei Geka 40:1071–1077

    PubMed  Google Scholar 

  9. 9.

    Shintaro Arai TM, Mizutani T, Matsumoto M, Nakajo T, Sumi K, Sugiyama T (2018) Creating a practice model using actual surgical instruments and training for cerebrovascular surgery: from setup to performing the microscopic technique. Surg Cereb Stroke (Jpn) 46:469–472

    Article  Google Scholar 

  10. 10.

    Sugita K, Hirota T, Mizutani T, Mutsuga N, Shibuya M, Tsugane R (1978) A newly designed multipurpose microneurosurgical head frame. Techn note J Neurosurg 48:656–657. https://doi.org/10.3171/jns.1978.48.4.0656

    Article  CAS  Google Scholar 

  11. 11.

    Sugita K, Kobayashi S, Takemae T, Matsuo K, Yokoo A (1980) Direct retraction method in aneurysm surgery. Techn note J Neurosurg 53:417–419. https://doi.org/10.3171/jns.1980.53.3.0417

    Article  CAS  Google Scholar 

  12. 12.

    Yoneyama T, Kawamata T, Tanaka M, Yamaguchi K, Okada Y (2015) Omnidirectional retractor-supporting ring as a new device for carotid endarterectomy. J Neurosurg 122:148–151. https://doi.org/10.3171/2014.9.jns132856

    Article  PubMed  Google Scholar 

Download references


All the authors have approved the manuscript and agree with submission to your esteemed journal. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. We thank our operating room staff at St. Luke’s Medical University for their best work and cooperation. We also thank Editage (www.editage.jp) for English language editing.

Author information




Y.O. initiated the project and invented the device presented in this manuscript. B.R., S. S., T.I., K.K., and Y.O. were involved in the design of experiments. B.R., S. S., T.I., and Y.O conducted experiments and analyzed data. B.R. and Y.O. wrote the manuscript. All authors discussed the results and commented on the paper.

Corresponding author

Correspondence to Bikei Ryu.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee (the institutional review board of St. Luke’s International Hospital, 19-R078) 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.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Ryu, B., Sato, S., Inoue, T. et al. A novel omnidirectional tin-alloyed ring retractor for craniotomy in neurosurgery: technical note. Neurosurg Rev (2020). https://doi.org/10.1007/s10143-020-01237-y

Download citation


  • Device
  • Omnidirectional
  • Retractor
  • Technique
  • Craniotomy
  • Neurosurgery