Endovascular Treatment of a Fusiform Aneurysm Involving a Premammillary Artery Originating from the Internal Carotid Artery: A Case Report.

The premammillary artery (PMA) is a branch of the posterior communicating artery (PCoA). While the PMA is known to originate from the PCoA as demonstrated by most anatomical studies, it originates directly from the internal carotid artery in approximately 1% of patients. Cerebral aneurysms associated with the PMA have rarely been reported. We report an extremely rare case of a ruptured PMA aneurysm that was managed using endovascular treatment.