Abstract
Introduction In sphenoid sinuses with ill-defined carotid bony landmarks, accidental injury of
the internal carotid artery (ICA) remains one of the most challenging complications,
which is particularly reported in the endoscopic endonasal transsphenoidal approaches
(EETAs).
Objectives To describe an anatomical model for the endoscopic orientation of the juxta-pituitary
segment of the ICA in relation to the lateral opticocarotid recess (OCR) as a nearby
bony landmark.
Methods Dissection was performed progressively, simulating the EETA, in twenty fresh adult
cadavers. After reducing the posterior and lateral walls of the sphenoid sinuses,
various measurements were taken from both lateral OCRs to “contact points” on the
juxta-pituitary segment of the ICA and lateral margins of the pituitary gland.
Results The current results have enabled us to divide the region between the lateral OCRs
into 3 compartments: 2 lateral parasellar compartments contain juxta-pituitary segments
of the ICA with a mean width of 8 mm and a narrow range from 7 mm to 10 mm; and a
central intercarotid sellar compartment represents the safe region for bone drilling,
showing widely variable widths ranging from 9 mm to 20mm. In all specimens, the variation
in the width of the intercarotid compartment correlated with the distance between
both lateral OCRs.
Conclusion The present study improves surgeon awareness of the variations in the course of the
ICA through the EETA along sphenoid sinuses with ill-defined bony landmarks. An appreciation
of the measurements taken in the present study can help in operative training, and
can also provide a base for future studies to confirm ICA courses associated with
a higher risk of injury.
Keywords
cadaveric study - internal carotid artery - lateral opticocarotid recess - pituitary
gland - transsphenoidal approach
