[Functional significance of the internal carotid arteries and collateral circulation in cerebral aneurysm surgery].

The functional significance of the internal carotid artery was appraised in 18 patients with arterial, in 8 with arteriovenous aneurysms and in one patient with atherosclerosis of the cerebral vessels. The appraisal was based on changes in the intracarotid pressure and regional cerebral blood flow (quantitative criteria) in temporary occlusion of the internal carotid artery with a double-lumen balloon catheter and on the change in the patients' clinical condition during temporary or stationary arrest of blood flow through the internal carotid artery that is studied. In large arteriovenous aneurysms, the collateral circulation ensures adequate blood supply to the brain tissue on the side of temporary occlusion of the internal carotid artery. The functional importance of the internal carotid artery in patients with arterial aneurysms points to the possibility of reconstructive operations in aneurysms of the internal carotid artery which are inaccessible for direct intervention. However, it is expedient in every case to make sure that the operation is safe by preoperative appraisal by means of the suggested method.