Artikel
The anterior clinoid space
Suche in Medline nach
Autoren
Veröffentlicht: | 4. Mai 2005 |
---|
Gliederung
Text
Objective
The anterior clinoïd space forms the anterior part of the roof of the cavernous sinus and covers the superior orbital fissure. The anatomy of the dura mater, especially of the dural ring around the carotid artery, is difficult to understand. The aim of this work is to clarify this anatomy.
Methods
Cadaveric heads from 5 adults were studied by performing microdissection after injection with colorated neoprene latex (blue for veins, red for arteries). The specimen were fixed with a 20% formalin solution. Dissections were performed under surgical microscope and photographies were performed using an Hasselblad camera.
Results
To expose the anterior clinoid space ,the anterior clinoid process and the bone forming the roof and lateral wall of the optic canal have to be drilled. The anterior clinoïd process is anchored to the sphenoid bone with 3 points. The lateral one forms the lesser wing of the sphenoïd bone whereas medially the inferior and superior attachment points form the floor and the roof of the optic canal. The floor of the optic canal is called the optic strut. The encephalic dura mater which covers the superior part of the anterior clinoid process forms medially the distal dural ring around the carotid artery. The dura mater which covers the inferior part of the anterior clinoïd process forms the proximal dural ring of the carotid artery. Between these dural rings lies the clinoïd segment of the carotid artery which is not intracavernous and nor in the subarachnoid space. The distal dural ring of the carotid artery is just below the optic dural sheath. The carotidoculomotor membrane lies between the distal dural ring and the oculomotor dural sheath and forms the roof of the cavernous sinus. The oculomotor nerve pierces the roof of the cavernous sinus lateral to the posterior clinoid process and courses just below the carotidoculomotor membrane to reach the superior orbital fissure.
Conclusions
A better understanding of the anatomy of the roof of the cavernous sinus especially the anterior clinoïd space is usefull to approach the cavernous sinus or most frequently to drill the anterior clinoïd process to reach the optic canal for example.