Azygos anterior cerebral artery aneurysm associated with fenestration of the anterior cerebral artery.

Azygos ACA (Alpers et al. 1959; Bap tista et al. 1963; Pool et al. 1965), triple ACA (Baptista et al. 1963) and A1 fenestration (A1 pers et al. 1959; Crompton, 1962; Baptista et al. 1963; Teal et al. 1973; Ito et al. 1981; Krayenbuhl et al . 1982) are known as anomalies related to the anterior cerebral artery (ACA). Each of them is a rare vascular anomaly, and only a few reports have been presented concerning an aneurysm associated with such an anomaly (Crompton, 1962; Katz et al. 1978; Kondo et al. 1979; Huber et al. 1980; Ito et al. 1981; Niizuma et al. 1981; Inagawa et al. 1983; Matsumura and Nojiri, 1984; Kitami et al. 1985). This paper is a report of a case of an aneurysm occurring at the peripheral bifurcation of the azygos ACA together with fenestration at unilateral A1 and hypoplasia at contralateral A1. Case Renort