Endovascular coil embolization for an anomalous splenic artery aneurysm with a splenomesenteric trunk.

We present a case of a splenic artery (SA) aneurysm (SAA) that had arisen abnormally from the superior mesenteric artery in a 63-year-old man who underwent successful endovascular treatment. Although SAAs characterized by this anatomic abnormality are rare, in all 46 reported cases, the SAAs were located at the root of the SA and had originated abnormally from the superior mesenteric artery. This location is different from that of orthotopic SAAs, which are mostly located in the distal third of the SA. The differences in hemodynamics due to the anatomic abnormalities might play an important role in the formation of the anomalous SAAs.