An alternative extradural exposure to the anterior clinoid process: the superior orbital fissure as a surgical corridor.
OBJECTIVE
Dolenc has pioneered the extradural approach to the anterior clinoid process (ACP) in approaching the cavernous sinus, clinoidal space, and orbital apex. A key step is the division of the frontotemporal dural fold (FTDF). Less experienced surgeons may not be as versatile in their three-dimensional understanding of the superior orbital fissure and thus may risk injury to its contents. Through our cadaveric and subsequent clinical experience, we have devised a modification of the approach that permits safer handling of the contents of the superior orbital fissure.


METHODS
In five consecutive injected cadaveric heads (10 sides), we performed on one side a traditional extradural exposure of the ACP. On the other side, we performed our alternative dissection. Instead of exposing the ACP from medial to lateral and dividing the frontotemporal dural fold along the assumed path of safety, we followed the edge of the lesser wing from lateral to medial, uncovered the superior orbital fissure, and peeled the outer layer of the cavernous sinus medial to the foramen rotundum along the greater wing, thus uncovering the inferolateral surface of the ACP. This allowed dural division under full visualization.


RESULTS
The alternative method proved easier and more reliable in every case. We applied this technical modification in seven patients with no complications. Specifically, there was no injury to the oculomotor, lacrimal, frontal, or trigeminal nerves or branches. We present detailed anatomic expositions of the injected specimens.


CONCLUSIONS
This technical modification of the extradural approach of Dolenc is a simple, safe, and valuable adjunct to the exposure of the ACP. We recommend its use particularly by relatively inexperienced surgeons.
Coscarella
Ernesto
E
Department of Neurological Surgery, University of Miami School of Medicine, Miami, Florida 33136, USA.
Başkaya
Mustafa K
MK
Morcos
Jacques J
JJ
D001927:Brain Diseases / Q000473:pathology* / Q000601:surgery*; D002343:Carotid Artery, Internal / Q000473:pathology / Q000601:surgery; D002426:Cavernous Sinus / Q000473:pathology / Q000601:surgery; D003391:Cranial Nerves / Q000473:pathology / Q000601:surgery; D004388:Dura Mater / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D019635:Neurosurgical Procedures / Q000379:methods*; D009915:Orbit / Q000473:pathology* / Q000601:surgery*; D013100:Sphenoid Bone / Q000473:pathology* / Q000601:surgery*