Introduction: Meckel's Cave may be accessed percutaneously through the Foramen Ovale (FO). Detailed knowledge of the region’s anatomical surroundings is invaluable in improving target accuracy and preventing complications with this approach. A comprehensive cadaveric study of the region traversed by needle is thus presented.
Methods: Three cadaveric heads (six sides) were fixed in formaldehyde and injected with latex. A detailed description of the vascular structures contained in the needle's trajectory from the puncture site to the foramen ovale was performed. An imaginary inverted pyramid was outlined and divided in three segments. An inferior segment comprises the apex of the pyramid, where the probe enters the cheek, to the parotid duct. The middle third segment goes from the parotid duct to the external pterygoid muscle (EPM) and a superior third from the EPM to the base of the medial cranial fossa.
Results: Facial artery and vein distal branches are contained in the inferior third. The middle third is 50% avascular except in the cases where the MA is lateral to the EPM . In the superior third the probe is in close relationship to the MA in 50% of the cases. The Internal carotid artery has three relationships with the probe (posterior with the cervical pre-styloid portion, posteromedial at the carotid canal and medial at the foramen lacerum). The middle meningeal artery are slightly posterior to the probe. The Jugular vein is posterior to the probe.
Conclusions: The upper third of the imaginary pyramid for the transforaminal approach represents the more dangerous part of the transforaminal ovale approach. Although the MA can be of concern the artery runs freely as opposed to the Internal carotid artery and the Internal jugular vein.
Patient Care: To know the vascular anatomy of the transforamen oval approach therefore decrease the likelihood of adverse vascular events.
Learning Objectives: To know the vascular anatomy of the transforamen oval approach.