The Relationship Between the Direction of Putaminal Intracerebral Hemorrhage and Anterior Cerebral Artery Predominance

ObjectiveIt is expected that anatomic variations in the circle of Willis have a direct effect on blood flow in the internal carotid artery. Rupture of the lenticulostriate artery of the middle cerebral artery 1st segment (M1) is the most common cause of putaminal intracerebral hemorrhage (ICH), and we hypothesized that this could be related to the anatomic variations of the circle of Willis and the predominance of the anterior cerebral artery 1st segment (A1).MethodsWe retrospectively reviewed the records of 544 patients who were treated for spontaneous ICH between 2013 and 2016 at Yeungnam University Hospital. Among them, 83 patients (49 men and 34 women; mean age, 60.38 years; range, 34-87 years) were admitted for the treatment of putaminal ICH. The circle of Willis was visualized on the basis of computed tomographic (CT) angiographic images with 3-dimensional (3D) reconstruction images. The number of putaminal ICH patients who showed differences in diameter between the right and left A1 segments, with a normal variation of the anterior cerebral artery (ACA), was analyzed.ResultsAmong 83 patients with spontaneous ICH, 46 and 37 had left and right putaminal hemorrhages, respectively. Sixty-seven patients were treated conservatively, and 16 patients underwent surgery. The number of patients with a dominant A1 segment on either side was 58 (67.4%). Forty patients had a dominant A1 segment and putaminal ICH located in the same direction (P = 0.007).ConclusionIt was concluded that putaminal ICHs occur more frequently on the side of the dominant A1 segment. This information can help an understanding of the mechanism of putaminal spontaneous ICH development and may even assist in the treatment of ICH.