Download PDF
J Neurol Surg B Skull Base 2019; 80(05): 469-473
DOI: 10.1055/s-0038-1675591
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Quantitative Analysis of Surgical Working Space During Endoscopic Skull Base Surgery

Joel C. Davies   *
1   Department of Otolaryngology–Head and Neck Surgery/Surgical Oncology, Princess Margaret Cancer Centre and Guided Therapeutics (GTx) Program, University of Toronto, Toronto, Ontario, Canada
,
Harley H.L. Chan   *
1   Department of Otolaryngology–Head and Neck Surgery/Surgical Oncology, Princess Margaret Cancer Centre and Guided Therapeutics (GTx) Program, University of Toronto, Toronto, Ontario, Canada
,
Christopher M.K.L. Yao
1   Department of Otolaryngology–Head and Neck Surgery/Surgical Oncology, Princess Margaret Cancer Centre and Guided Therapeutics (GTx) Program, University of Toronto, Toronto, Ontario, Canada
,
Michael D. Cusimano
2   Division of Neurosurgery, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
3   Li Ka Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
,
Jonathan C Irish
1   Department of Otolaryngology–Head and Neck Surgery/Surgical Oncology, Princess Margaret Cancer Centre and Guided Therapeutics (GTx) Program, University of Toronto, Toronto, Ontario, Canada
,
John M Lee
3   Li Ka Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
4   Department of Otolaryngology–Head and Neck Surgery, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
› Author Affiliations
Further Information

Publication History

01 September 2018

27 September 2018

Publication Date:
26 November 2018 (online)

    Permissions and Reprints

Abstract

Objectives Selective dissection of intranasal anatomy may improve visualization and maneuverability at the skull base. We aimed to quantify the dimensions of working space and angles achieved following sequential removal of intranasal structures using an endoscopic transphenoidal approach to the skull base.

Methods Cone beam computed tomography scans of four cadaveric heads were obtained for registration of an optical tracking system. Each head was sequentially dissected: (1) sphenoidotomy and limited posterior septectomy, (2) unilateral partial middle turbinectomy, (3) bilateral partial middle turbinectomy, and (4) wide posterior septectomy. The maximal craniocaudal and mediolateral distance (mm) and angle (degrees) reached were calculated at the sphenoid face and sella. Data were analyzed using descriptive statistics and tests of statistical significance. The significance level was set at p  ≤  0.05.

Results A significant improvement in both dimensions of working space was observed with each stage of dissection at the level of the sphenoid face. Maximal working space was achieved following bilateral middle turbinectomy and wide posterior septectomy with a 38 and 29% increase in working space in the mediolateral and craniocaudal dimensions, respectively. The largest stepwise increase in working space was observed with unilateral middle turbinectomy (mediolateral: 24 ± 3 mm and craniocaudal: 20 ± 3 mm). A trend toward improved degrees of visualization was observed with each stage of dissection but was not statistically significant.

Conclusion Approaches to the skull base can be enhanced by selective unilateral/bilateral partial middle turbinectomy and posterior septectomy being performed to improve visualization and maximize surgical working freedom.

Keywords

endoscopic surgery - skull base anatomy - transsphenoidal - three dimensional modeling

* Joel C. Davies and Harley H.L. Chan contributed equally to this study.


 

  • References

  • 1 Jho HD, Ha HG. Endoscopic endonasal skull base surgery: Part 3--The clivus and posterior fossa. Minim Invasive Neurosurg 2004; 47 (01) 16-23
    Article in Thieme ConnectPubMedGoogle Scholar
  • 2 Schwartz TH, Fraser JF, Brown S, Tabaee A, Kacker A, Anand VK. Endoscopic cranial base surgery: classification of operative approaches. Neurosurgery 2008; 62 (05) 991-1002 , discussion 1002–1005
    CrossrefPubMedGoogle Scholar
  • 3 Cavallo LM, Messina A, Cappabianca P. , et al. Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations. Neurosurg Focus 2005; 19 (01) E2
    PubMedGoogle Scholar
  • 4 Beule AG. Physiology and pathophysiology of respiratory mucosa of the nose and the paranasal sinuses. GMS Curr Top Otorhinolaryngol Head Neck Surg 2010; 9: Doc07
    PubMedGoogle Scholar
  • 5 Barham HP, Gould EA, Ramakrishnan VR. Swing technique for middle turbinate preservation in expanded endonasal skull base approaches. Int Forum Allergy Rhinol 2014; 4 (07) 583-586
    CrossrefPubMedGoogle Scholar
  • 6 de Notaris M, Prats-Galino A, Enseñat J. , et al. Quantitative analysis of progressive removal of nasal structures during endoscopic suprasellar approach. Laryngoscope 2014; 124 (10) 2231-2237
    CrossrefPubMedGoogle Scholar
  • 7 Guthikonda B, Nourbakhsh A, Notarianni C, Vannemreddy P, Nanda A. Middle turbinectomy for exposure in endoscopic endonasal transsphenoidal surgery: when is it necessary?. Laryngoscope 2010; 120 (12) 2360-2366
    CrossrefPubMedGoogle Scholar
  • 8 Wu V, Cusimano MD, Lee JM. Extent of surgery in endoscopic transsphenoidal skull base approaches and the effects on sinonasal morbidity. Am J Rhinol Allergy 2018; 32 (01) 52-56
    CrossrefPubMedGoogle Scholar
  • Siewerdsen JH, Daly MJ, Chan H. , et al. High-performance intraoperative cone-beam CT on a mobile C-arm: an integrated system for guidance of head and neck surgery. Proc SPIE 2009; 7261 :7261 0J–8
    PubMedGoogle Scholar
  • 10 Nyquist GG, Anand VK, Brown S, Singh A, Tabaee A, Schwartz TH. Middle turbinate preservation in endoscopic transsphenoidal surgery of the anterior skull base. Skull Base 2010; 20 (05) 343-347
    Article in Thieme ConnectPubMedGoogle Scholar
  • 11 de Almeida JR, Snyderman CH, Gardner PA, Carrau RL, Vescan AD. Nasal morbidity following endoscopic skull base surgery: a prospective cohort study. Head Neck 2011; 33 (04) 547-551
    CrossrefPubMedGoogle Scholar