A CLASSIFICATION OF JUXTA-DURAL RING ANEURYSMS WITH REFERENCE TO SURGICAL ANATOMY

We report a subgroup of internal carotid artery (ICA) aneurysms locate d near the carotid ring which we call juxtadural ring aneurysms. These aneurysms are classified into three types: paraclinoid intradural, ca rotid cave and infraclinoid extradural aneurysms. The paraclinoid intr adural aneurysms arise from the ICA distal to the origin of the ophtha lmic artery and are close to the dural ring, which may include some so -called carotid-ophthalmic aneurysms. The carotid cave aneurysms are l ocated in the carotid cave which is seated in the infraclinoid carotid groove and proximal to the origin of the ophthalmic artery. They are located at the angiographical genu and in the intradural space anatomi cally. The infraclinoid extradural aneurysms are located close to the dural ring extradurally in the infraclinoid carotid groove sinus, a pe ripheral venous space of the cavernous sinus. The infraclinoid extradu ral aneurysms should be differentiated from aneurysms in the cavernous sinus, because they are located in the infraclinoid carotid groove si nus. (C) 1996 Pearson Professional Ltd