Quantitative verification of the keyhole concept: a comparison of area of exposure in the parasellar region via supraorbital keyhole, frontotemporal pterional, and supraorbital approaches

Laboratory investigation

Restricted access

Object

This study was designed to determine if the “keyhole concept,” proposed by Perneczky's group, can be verified quantitatively.

Methods

Fourteen (3 bilateral and 8 unilateral) sides of embalmed latex-injected cadaveric heads were dissected via 3 sequential craniotomy approaches: supraorbital keyhole, frontotemporal pterional, and supraorbital. Three-dimensional cartesian coordinates were recorded using a stereotactic localizer. The orthocenter of the ipsilateral anterior clinoid process, the posterior clinoid process, and the contralateral anterior clinoid process are expressed as a center point (the apex). Seven vectors project from the apex to their corresponding target points in a radiating manner on the parasellar skull base. Each 2 neighboring vectors border what could be considered a triangle, and the total area of the 7 triangles sharing the same apex was geometrically expressed as the area of exposure in the parasellar region.

Results

Values are expressed as the mean ± SD (mm2). The total area of exposure was as follows: supraorbital keyhole 1733.1 ± 336.0, pterional 1699.3 ± 361.9, and supraorbital 1691.4 ± 342.4. The area of exposure on the contralateral side was as follows: supraorbital keyhole 602.2 ± 194.7, pterional 595.2 ± 228.0, and supraorbital 553.3 ± 227.2. The supraorbital keyhole skull flap was 2.0 cm2, and the skull flap size ratio was 1:5:6.5 (supraorbital keyhole/pterional/supraorbital).

Conclusions

The area of exposure of the parasellar region through the smaller supraorbital keyhole approach is as adequate as the larger pterional and supraorbital approaches. The keyhole concept can be verified quantitatively as follows: 1) a wide area of exposure on the skull base can be obtained through a small keyhole skull opening, and 2) the side opposite the opening can also be visualized.

Article Information

Address correspondence to: Johnny B. Delashaw Jr., M.D., Department of Neurological Surgery, University of California, Irvine, 200 South Manchester Avenue, Suite 210, Orange, California 92868. email: delashaw@uci.edu.

Please include this information when citing this paper: published online November 9, 2012; DOI: 10.3171/2012.9.JNS09186.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Illustration of the surgical views of the supraorbital keyhole (A), the pterional (B), and supraorbital (C) approaches. Printed with permission from Andy Rekito, M.S.

  • View in gallery

    Photographs of the sequential cadaveric head dissection (right side). A: Bone cuts are marked for the supraorbital keyhole, pterional, and supraorbital approaches. B: A spatula holding the orbital frontal lobe through the supraorbital keyhole approach is shown. This spatula position remains unchanged during sequential dissection. C: The pterional bone flap is reconstructed back to the bone edge with wires. D: The supraorbital bone flap is removed, revealing the periorbital tissue and the cut frontal sinus.

  • View in gallery

    Photographs of the target points obtained via the supraorbital keyhole approach. A: View from above of the right supraorbital keyhole approach with a brain spatula held in place. B: Needle pointer tip on the ipsilateral olfactory groove, Point 1. C: Needle pointer tip on the ipsilateral sphenoid ridge, Point 2. D: Needle pointer tip on the ipsilateral petrosal ridge, Point 3. E: Needle pointer tip on the ipsilateral P2 segment of the posterior cerebral artery, Point 4. F: Needle pointer tip on the basilar artery, Point 5. G: Needle pointer tip on the contralateral petrosal ridge, Point 6. H: Needle pointer tip on the contralateral sphenoid ridge, Point 7.

  • View in gallery

    Illustration showing the different areas of exposure. The area of exposure was simulated as a heptagon in 3D space. The center (Point 0) is depicted as the center of the skull base. From Point 0, 7 vectors radiate to their peripheral-most targets (Points 1–7). See text for details. Printed with permission from Andy Rekito, M.S.

  • View in gallery

    Bar graph showing the area of exposure for each approach. The white bars represent the total area of approach, and the black bars represent the contralateral area of approach. KEY = supraorbital keyhole approach; PTE = pterional approach; SUP = supraorbital approach.

References

  • 1

    Al-Mefty O: Supraorbital-pterional approach to skull base lesions. Neurosurgery 21:4744771987

  • 2

    Beseoglu KLodes SStummer WSteiger HJHänggi D: The transorbital keyhole approach: early and long-term outcome analysis of approach-related morbidity and cosmetic results. Technical note. J Neurosurg 114:8528562011

    • Search Google Scholar
    • Export Citation
  • 3

    Czirják SSzeifert GT: Surgical experience with frontolateral keyhole craniotomy through a superciliary skin incision. Neurosurgery 48:1451502001

    • Search Google Scholar
    • Export Citation
  • 4

    Dare AOLandi MKLopes DKGrand W: Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation. Technical note. J Neurosurg 95:7147182001

    • Search Google Scholar
    • Export Citation
  • 5

    Delashaw JB JrTedeschi HRhoton AL: Modified supraorbital craniotomy: technical note. Neurosurgery 30:9549561992

  • 6

    Figueiredo EGDeshmukh VNakaji PDeshmukh PCrusius MUCrawford N: An anatomical evaluation of the minisupraorbital approach and comparison with standard craniotomies. Neurosurgery 59:4 Suppl 2ONS212ON2202006

    • Search Google Scholar
    • Export Citation
  • 7

    Fischer GStadie AReisch RHopf NJFries GBöcher-Schwarz H: The keyhole concept in aneurysm surgery: results of the past 20 years. Neurosurgery 68:1 Suppl Operative45512011

    • Search Google Scholar
    • Export Citation
  • 8

    Jane JAPark TSPobereskin LHWinn HRButler AB: The supraorbital approach: technical note. Neurosurgery 11:5375421982

  • 9

    Mitchell PVindlacheruvu RRMahmood KAshpole RDGrivas AMendelow AD: Supraorbital eyebrow minicraniotomy for anterior circulation aneurysms. Surg Neurol 63:47512005

    • Search Google Scholar
    • Export Citation
  • 10

    Patel RSYousem DMMaldjian JAZager EL: Incidence and clinical significance of frontal sinus or orbital entry during pterional (frontotemporal) craniotomy. AJNR Am J Neuroradiol 21:132713302000

    • Search Google Scholar
    • Export Citation
  • 11

    Ramos-Zúñiga RVelázquez HBarajas MALópez RSánchez ETrejo S: Trans-supraorbital approach to supratentorial aneurysms. Neurosurgery 51:1251312002

    • Search Google Scholar
    • Export Citation
  • 12

    Reisch RPerneczky A: Ten-year experience with the supraorbital subfrontal approach through an eyebrow skin incision. Neurosurgery 57:4 Suppl2422552005

    • Search Google Scholar
    • Export Citation
  • 13

    Reisch RPerneczky AFilippi R: Surgical technique of the supraorbital key-hole craniotomy. Surg Neurol 59:2232272003

  • 14

    Sánchez-Vázquez MABarrera-Calatayud PMejia-Villela MPalma-Silva JFJuan-Carachure IGomez-Aguilar JM: Transciliary subfrontal craniotomy for anterior skull base lesions. Technical note. J Neurosurg 91:8928961999

    • Search Google Scholar
    • Export Citation
  • 15

    Steiger HJSchmid-Elsaesser RStummer WUhl E: Transorbital keyhole approach to anterior communicating artery aneurysms. Neurosurgery 48:3473522001

    • Search Google Scholar
    • Export Citation
  • 16

    van Lindert EPerneczky AFries GPierangeli E: The supraorbital keyhole approach to supratentorial aneurysms: concept and technique. Surg Neurol 49:4814901998

    • Search Google Scholar
    • Export Citation
  • 17

    Yaşargil MGAntic JLaciga RJain KKHodosh RMSmith RD: Microsurgical pterional approach to aneurysms of the basilar bifurcation. Surg Neurol 6:83911976

    • Search Google Scholar
    • Export Citation
  • 18

    Yaşargil MGFox JL: The microsurgical approach to intracranial aneurysms. Surg Neurol 3:7141975

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 156 156 15
Full Text Views 238 238 4
PDF Downloads 137 137 0
EPUB Downloads 0 0 0

PubMed

Google Scholar