Medial-type persistent trigeminal artery and ipsilateral posterior communicating artery supplying bilateral posterior cerebral arteries combined with an aberrant right subclavian artery and bicarotid trunk.

Purpose: To describe a case of a medial-type persistent trigeminal artery (PTA) associated with multiple arterial variations.
Methods: A 34-year-old woman with multiple sclerosis underwent cranial magnetic resonance (MR) angiography from the aortic arch to the neck region and intracranial region for the evaluation of an unruptured cerebral aneurysm that was previously detected on MR imaging. The MR machine was a 3-T scanner.
Results: There was an aberrant right subclavian artery and bicarotid trunk, medial-type left PTA and ipsilateral posterior communicating artery (PCoA) supplying bilateral posterior cerebral arteries (PCAs). The unruptured aneurysm was located at the paraclinoid segment of the left internal carotid artery and was treated successfully by coil embolization via a transfemoral approach.
Conclusion: Only 10% of PTAs are classified as the medial type. The association with extremely large ipsilateral PCoA, which supplies the bilateral PCAs, has not been previously reported. Aberrant right subclavian arteries are common and are frequently associated with a bicarotid trunk. Before catheterization of the cerebral arteries, the aortic arch and its branches must be evaluated by MR angiography or computed tomography angiography to prevent catheterization failure via the right transradial approach.
(© 2023. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)