Introduction: The Meningo-orbital band (MOB) connects the periorbita and temporal and frontal lobe dura. Detaching the MOB enables wide exposure of the anterior clinoid process, the superior orbital fissure (SOF), and the anterior portion of the cavernous sinus, but increases the potential risk of cranial nerve injury.
Methods: Using five preserved cadaveric heads (10 sides) previously injected with colored latex, a stepwise detachment of the MOB was performed. A stepwise method was developed based on the microsurgical anatomy of the SOF, periosteal dura, dura propria, and epineurium layer. Each step was designed in order to fully expose the structure to be incised in the following step. The first step was partial unroofing of the lateral wall of the SOF, followed by incision of the lateral periosteal dura and peeling off of the dura propria of the temporal lobe, and ultimately incision of the MOB and superior periosteal dura. Subsequently, this method was applied to clinical cases requiring an extracranial anterior clinoidectomy.
Results: Because this method is based on the precise anatomy of the SOF and its surrounding dural layers, the incision point for each step was made in order to maximally avoid cranial nerve injuries. Subsequent extradural anterior clinoidectomies were relatively simple due to the wide surgical corridor.
Conclusions: A stepwise detachment of the MOB, maximally avoiding cranial nerve injury, was performed on cadaveric specimens and subsequently living patients. Based on the complex anatomy of these structures, we recommended that surgeons possess sufficient anatomical knowledge before attempting this detachment surgically.
Patient Care: This study will enhance the surgeons understanding of the anatomy of the menigo-orbital band and hopefully help avoid complications resulting from cranial nerve injury.
Learning Objectives: By the conclusion of this session, participants should be able to understand (1) the microsurgical anatomy of the meningo-orbital band and (2) the dural layers associated with structures encountered during anterior clinoidectomies.