A method is described in which we use a combined endovascular balloon-catheter technique and open microneurosurgical approach for clipping aneurysms of the proximal paraclinoidal intracranial segment of the internal carotid artery. By temporary occlusion of the cervical carotid artery and continuously retrograde sucking of blood from the distal vessel via a double-lumen balloon-catheter, clip application to large and critically located aneurysms is facilitated applying evacuation-decompression to the trapped arterial segment under intra-operative SEP-monitoring.