Persistent Primitive Trigeminal Artery Imaged by Three-dimensional Computed Tomography Angiography —Two Case Reports—

Abstract

Three-dimensional computed tomography (3D CT) angiography was used to investigate two cases of persistent primitive arteries. 3D CT angiography and 3D CT demonstrated a persistent primitive trigeminal artery variant penetrating the lateral edge of the posterior clinoid process and running to the posterior medial side, and a persistent primitive trigeminal artery perforating the canal of the posterior clinoid process and the petrosal bone junction. 3D CT angiography can delineate these persistent primitive arteries and the anatomy relative to the bone structure simultaneously, so is very useful to identify the arterial line where the canal is penetrated.

Persistent trigeminal artery: angio-tomography and angio-magnetic resonance finding

“…DisCussion during the intracranial vascular development in the embryo (approximately 35 days of gestational age), four main temporally anastomosis arise between carotid and vertebral-basilar systems: the trigeminal, optical, hypoglossal and proatlantal intersegmental [1][2][3][4] . These anastomosis persist for about 1 week and disappear with the subsequent development of posterior communicants and vertebral arteries 1 .…”

“…The prevalence of a PTA in patients with trigeminal neuralgia is 2.2%, in a study performed by Bondt et al and neurovascular compression was assumed to be present if the patient showed clinical features of trigeminal neuralgia, if there was contact between an artery and the trigeminal nerve on the affected side, and if other pathology had been excluded 8 . The PTA is easily identified by MR angiography, however, the exact location of the drilling of the skull base is impossible to be identified by these methods 3 . small trigeminal arteries cannot be identified in spin-echo T1 and T2 sequences, it is only possible with the MR angiography 6 .…”

“…Patients with PTA associated with vascular malformation, cerebral aneurysm or trigeminal neuralgia may need surgical treatment. Therefore, the relationship of these vessels with the skull base must be well characterized, and CT angiography is a good method for simultaneous visu- alization of bone and vascular structures 3 . Moreover, recognizing these vessels before endovascular procedures is of great importance in accessing the risk of emboli passing through these vessels during embolization therapies.…”

“…It goes from the internal carotid artery (ICA) to the basilar artery, at the level of the cavernous sinus [1][2][3][4] . It reaches the basilar artery in two ways: in 50% of cases, it penetrates the sella turcica, runs in its own groove and perforates the dura near the clivus to then join the basilar artery between the anterior inferior cerebellar arteries and the superior cerebellar arteries.…”

“…In most cases it is an incidental finding, but may be associated with malformations, aneurysms or anomalies in other blood vessels. Patients may be asymptomatic or present symptoms due to low flow of posterior circulation or carotid microembolization from posterior circulation [2][3] . yet, PTA can cause trigeminal neuralgia 5,6 .…”