Article
Orbitozygomatic approach – transition from "large and lavish" to "small and simple"
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Authors
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Thomas Kretschmer
- Evangelisches Krankenhaus Oldenburg, Universitätsklinik für Neurochirurgie, Oldenburg, Deutschland
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Thomas Schmidt
- Universitätsklinik für Neurochirurgie Oldenburg, Evangelisches Krankenhaus-Universität Oldenburg, Oldenburg, Deutschland
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Christian Heinen
- Universitätsklinik für Neurochirurgie, Medizinischer Campus Carl-von-Ossietzky-Universität Oldenburg, Evangelisches Krankenhaus, Oldenburg, Deutschland
| Published: | June 9, 2017 |
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Outline
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Objective: In selected cases a kranio-orbital extension of a classic pterional or lateral supraorbital approach can give the extra space to the dissection corridor that makes some pathology more amenable to resection. The classic orbitozygomatic approach (OZ) combines a fronto-temporal craniotomy with variable orbital unroofing and transection of the zygomatic process of the os-frontale. With this extensive bone-removal the temporo-frontal base is widely accessible and the trajectory angle is largened. However, the approach is time-consuming, tissue burdening, and risks temporal atrophy and enophtalmos. We describe a fast and simple, very tissue sparing modular minimized techniqual variant of the orbito-zygomatic (kranio-orbital) approach.
Methods: The classic technique uses a 6 step orbital unroofing technique, necessitating 6 major bone cuts. Variants are a one and two-piece method. Each of them uses a McCarty keyhole and variable additional burr holes. The reciprocating saw is inserted deeply into the bony orbit.
Precondition is extensive, multi layered temporal muscle and superficial fascia mobilization and incision with substantial muscle disconnection also close to its coronoid insertion plus extensive periorbital mobilization.
Due to extensive dissection with potential for unfavorable cosmetic result we abandoned this technique. In a first step we combined a conventional complete lateral supraorbital craniotomy (LSO) with separate orbital unroofing that is manageable via a regular combined skin-muscle flap. For bone exposure a skin incision of 7-10 cm suffices. The combined skin-muscle flap does not necessitate more than conventional temporal muscle incision and results in a favorable cosmetic result. We limit the use of the reciprocating saw to two minimal starter cuts on the medial and lateral orbital rim (thin blades, minimal bone loss) and use small straight and bent chisels two create the pyramidal bone fissures to unroof the orbit. The two-piece method enables unroofing under vision.
In a next step we changed to a single-piece OZ by combining the same but now u-shaped, uncomplete craniotomy with blind chisel unroofing via the orbital rim starter notches.
Results: This type of bone flap only takes 5-10 minutes longer than a standard LSO. It uses the same type of skin incision and the reinserted flap shows excellent alignment.
Conclusion: In the rare cases we need an orbitozygomatic skull base approach we nowadays limit it to a one-piece mini variant with a 7-10 cm skin incision and a combined skin-muscle flap due to ease of use, reduced invasiveness and excellent cosmetic result.
