The authors present the results of microsurgical treatment of aneurysms in the distal portion of the anterior cerebral artery in 23 patients who were operated during the last 10 years. All aneurysms were saccular and manifested by subarachnoidal haemorrhage. In 3 patients there was an incidental finding of multiple aneurysms. Aneurysms of the distal anterior cerebral artery at the site of insertion of the a. callosomarginalis were found in 20 patients (87 %), in 2 patients (8.7 %) they were in a proximal position and in one patient distally from that site. In 20 patients (87 %) on CT examinations signs of subarachnoidal haemorrhage were present, in 8 (35 %) there were signs of a small intracerebral haematoma and in two patients (8.7 %) of a haematoma larger than 25 mm in diameter, in 4 (17.4 %) they were combined with intraventricular haemorrhage. Seven patients (30.4 %) had a neurosurgical ope- ration in the acute stage within the third day after development of a stroke. In 21 cases (91.3 %) the frontal, paramedian, interhemispheric approach was used – in 11 from the right and in 10 from the left – depending on the site of the bridging veins in the frontal area and inclination of the aneurysmal sac to the gyrus cinguli. Before surgery 15 patients (65.2 %) were in HH 1 – 2, 5 patients – HH 3 and three suffered from – HH 4 grade. A total of 21 patients (91.3 %) are in a satisfactory state after surgery (GOS 5.4), two died (8.7 %) – one before surgery HH 4, the other – HH 1 – because of the development of severe vasospasms of the cerebral arteries. Nine patients (39.1 %) suffered from mild mental changes which persisted after surgery. The results revealed that even in these special aneurysms microneurosurgical treatment can produce favourable results.

        Key words: anterior cerebral artery, saccular aneurysms, subarachnoidal haemorrhage, surgical