At a glance
- Variants
- One-piece, two-piece; supraorbital (modified) OZ
- Targets
- Cavernous sinus, interpeduncular fossa, basilar apex, orbit
- Gain over pterional
- Less brain retraction; upward trajectory
- Key risks
- Frontalis branch, enophthalmos, temporalis atrophy
- Combined with
- Anterior clinoidectomy, transcavernous route
Overview and history
Hakuba and colleagues described the orbitozygomatic infratemporal approach in 1986[1], and Zabramski and colleagues described a practical orbitozygomatic craniotomy technique[2]. Removing the orbital rim and roof and the zygomatic arch increases the exposure gained from the pterional craniotomy, mainly by lowering the angle of approach so that the surgeon looks up toward the target rather than retracting the frontal and temporal lobes.
Indications
- Large or complex aneurysms of the anterior circulation and the basilar apex, especially high-riding basilar bifurcations.
- Skull-base meningiomas of the sphenoid wing, clinoid, cavernous sinus and spheno-orbital region.
- Large craniopharyngiomas and pituitary tumours with lateral or superior extension.
- Lesions of the orbit, the interpeduncular fossa and the upper brainstem.
Surgical anatomy
The frontal (temporal) branch of the facial nerve crosses the zygomatic arch within the superficial temporal fat pad, superficial to the deep temporal fascia; interfascial or subfascial dissection protects it[3]. The supraorbital nerve emerges through a notch or foramen on the orbital rim and must be freed. The orbital roof separates the periorbita from the frontal lobe, and the lateral orbital wall is shared with the middle fossa and the temporal fossa. The zygomatic arch and body give origin to the masseter.
Operative steps
- Supine, head turned 30–45° and extended so that the malar eminence is the highest point.
- Curvilinear incision behind the hairline to the zygoma; interfascial dissection of the temporalis to protect the frontal branch.
- Release the supraorbital nerve; dissect the periorbita from the roof and lateral wall of the orbit.
- Elevate the temporalis muscle down to the infratemporal fossa after dividing or releasing the zygomatic arch.
- Perform a pterional craniotomy and then remove the orbitozygomatic bar (two-piece), or remove both together (one-piece).
- Flatten the sphenoid wing and orbital roof; open the dura and split the Sylvian fissure.
- Reconstruct the orbital roof and rim and fix the arch with plates to prevent enophthalmos and facial asymmetry.
Complications and how to avoid them
- Frontalis palsy from injury to the frontal branch of the facial nerve.
- Temporalis atrophy and jaw pain (trismus).
- Enophthalmos or pulsatile exophthalmos from an unrepaired orbital roof.
- Periorbital swelling, supraorbital numbness and CSF leak through an opened frontal sinus.
Take-home
Surgical pearls
- Use it when you need to look up: high basilar apex, large suprasellar tumours.
- The orbital rim cut gains more working angle than the zygomatic cut for most anterior targets.
- Repair the orbital roof to prevent pulsatile enophthalmos.
Related
References
- 1.Hakuba A, Liu S, Nishimura S. The orbitozygomatic infratemporal approach: a new surgical technique. Surg Neurol. 1986;26(3):271-276.
- 2.Zabramski JM, Kiriş T, Sankhla SK, et al. Orbitozygomatic craniotomy. Technical note. J Neurosurg. 1998;89(2):336-341.
- 3.Yaşargil MG, Reichman MV, Kubik S. Preservation of the frontotemporal branch of the facial nerve using the interfascial temporalis flap for pterional craniotomy. J Neurosurg. 1987;67(3):463-466.
General education for medical professionals. It summarises published literature and is not advice for any individual patient or a substitute for supervised surgical training.