THE BLOOD-SUPPLY OF THE INTRACAVERNOUS CRANIAL NERVES - AN ANATOMIC STUDY

CRANIAL NERVE DEFICITS are the most common complications of cavernous sinus surgery. Often the deficit occurs despite anatomic preservation of the nerve, and ischemic injury is thought to be the cause. A better understanding of the blood supply of these nerves may help to prevent such complications. The authors performed a cadaveric microsurgical s tudy of the intracavernous cranial nerves and their blood supply in 20 cavernous sinuses. The oculomotor nerve received branches from the in ferolateral trunk or its equivalent in all specimens (100%). The proxi mal trochlear nerve received branches from the inferolateral trunk in 80% of the specimens and from the tentorial artery of the meningohypop hyseal trunk in 20%. The distal half was supplied by the branches from the inferolateral trunk only. In the region of Dorello's canal, the p roximal third of the abducens nerve received branches from the dorsal clival artery of the meningohypophyseal trunk. The middle and distal t hirds received branches from the inferolateral trunk. The ophthalmic a nd proximal maxillary segments of the trigeminal nerve received branch es from the inferolateral trunk. The distal maxillary segment was supp lied by the artery of the foramen rotundum. In the majority of cases, the medial third of the Gasserian ganglion received branches from both the inferolateral trunk and the tentorial artery. The middle third of the ganglion received branches from either the inferolateral trunk or the middle meningeal artery. Our findings indicate the important role the intracavernous branches of the internal carotid artery play in th e blood supply of the intracavernous cranial nerves, and stress the ne ed to preserve these branches to prevent or minimize postoperative def icits.