Azygos Anterior Cerebral Artery Aneurysm

Abstract

Seven cases of aneurysms with azygos anterior cerebral artery are reported. Two were males and 5 were females. The ages of the patients on admission ranged from 47 to 61, the average being 56 years. Two cases out of 7 also had middle cerebral artery aneurysms and one had two aneurysms of the azygos anterior cerebral artery. Preoperative clinical features were complicated: moderate to severe psychic changes (5 out of 7), urinary incontinence without disturbance of consciousness (3 out of 5), hemiparesis (1 out of 7), and paraplegia with one upper limb paresis (2 out of 7). Aneurysms were found to arise near the genu of the corpus callosum in six cases; in four cases, they were located on the distal portion of the azygos anterior cerebral artery at its junction with two pericallosal arteries. In one, the aneurysm was on the middle portion of the azygos anterior cerebral artery at its junction with the frontopolar artery. In another case, the aneurysm was on the pericallosal artery at its junction with the callosomarginal artery after the azygos artery had branched. In another one, the aneurysm was on the proximal portion and radiologically simulated the anterior communicating artery aneurysm because the azygos anterior cerebral artery was short in length, about 10 mm. One was accompanied by the hydrocephalus. All aneurysms were clipped. A lumbo-peritoneal shunt was done in one case with hydrocephalus. Follow-up results after the operation revealed that four had full working capacity, two were partially disabled and one was totally disabled. The distal anterior cerebral artery aneurysms are frequently associated with the azygos anterior cerebral artery, of which the common trunk irrigates both cerebral hemispheres. Its clinical features are complicated. One must keep in mind this anomaly during the radiological examination of such patients and should take particular care during the operation to avoid injury of this common trunk.