The Ventral Endoscopic Anatomy of the Intracavernous Branches of the Internal Carotid Artery and Its Surgical Correlations
Background: Intra-cavernous branches of the internal carotid artery provide the vascular supply to cranial nerves III, IV, VI, the Gasserian Ganglion and trigeminal branches. They are also involved in the supply of tumors of the cavernous sinus and petroclival junction.
Objective: Assess the anatomy of the intracavernous branches of the internal carotid artery from the endoscopic endonasal perspective and revise their surgical correlations.
Material and Methods: Sixteen adult cadaveric fresh heads, with colored latex-injected common carotid arteries, were used for anatomical dissection of 32 cavernous sinuses with endoscopic endonasal technique.
Results: In all 32 explored cavernous sinuses the presence of the two principal intracavernous branches was demonstrated: the infero-lateral trunk and the meningohypophyseal trunk, both dividing into several branches with specific relationship with the cranial nerves. The infero-lateral trunk is dorsal to cranial nerve VI and carotid sympathetic fibers. As long as the plane of the VI cranial nerve is not transgressed during endonasal cavernous sinus surgery, the cranial nerves' vascular supply is preserved. In addition to the cranial nerves, the meningo-hypopophyseal trunk provides supply to the petroclival junctions and clivus.
Conclusion: Knowledge of the anatomy of the intracavernous branches of the internal carotid artery is essential in endoscopic endonasal surgery. Their preservation is crucial to avoid post-operative cranial nerve damages or intra- or post-operative bleeding. The endoscopic endonasal approach allows the surgeon to respect these vessels by virtue of the medial to lateral trajectory for Cavernous Sinus and Meckel's Cave surgeries. Furthermore, this route allows an early visualization of the pathological feeders, deriving from these arteries, for tumors of the spheno-clival junction, thus permitting control of these vessels in the first surgical steps.