A case of unruptured aneurysm at the junction of the cavernous segment
of the right internal carotid artery and the primitive trigeminal art
ery (PTA) is presented. The posterior circulation was not dependent on
PTA, thus the PTA was of an adult type in this case. This patient was
successfully treated by external carotid artery-anterior temporal art
ery long vein graft bypass, internal carotid artery ligation at neck,
and PTA clipping through the right subtemporal approach. A follow-up a
ngiography showed thrombotic occlusion of the aneurysm. In review of t
he literature, there are 27 cases reported of PTA aneurysm; among them
only 11 cases, including ours, treated surgically. The surgical treat
ment plan for PTA aneurysm, according to the review of literature is d
iscussed.