TEMPORARY ARTERIAL-OCCLUSION DURING INTRACRANIAL ANEURYSM SURGERY

Temporary arterial occlusion during intracranial aneurysm surgery is a safe and effective modality. It is not only an emergency measure for controlling aneurysmal bleeding, but also a helpful means for accurate and meticulous dissection and clipping of an intracranial aneurysm with the advantage of minimizing the chance of its premature rupture or causing damage to the vital neurovascular structures. This technique is especially useful for treating large or giant aneurysms, carotid-ophthalmic arterial aneurysms, or thin-walled and complicated aneurysms tightly adherent to their surrounding tissues. A series of 52 patients with temporary clipping of the involved arteries during intracranial aneurysm surgery were reviewed retrospectively, which represented 37.1% of all aneurysms operated on in Huashan Hospital, Shanghai Medical University during the same period (from 1980 to 1990). Of them, one died (1.9%), 10(19.2%) had immediate or early neurological deficits which were mostly resolved later. A follow-up study with an average time of 3.8 years showed that 98% of patients had an excellent and good recovery without significant deficits. Comparing these results with those in 88 patients with aneurysms operated on over the same period in which temporary clips were not used, there is clearly no significant difference. The use of brain protectors, barbiturates, hypothermia and some monitoring systems can increase the safe coefficient to the brain and reduce the occurrence of ischemic complications during the application of temporary arterial occlusion. However, there is so far neither an absolute reliable medication or monitor, nor a well-accepted safe time-limits to vascular occlusion. Therefore, the use of temporary arterial occlusion and time-limits for its application during the operation should be individualized depending basically on the patient's age, the clinical grade of the patint, the estimated adequacy of the collateral circulation, the location of the aneurysm and its relation to the surrounding tissues, the site of the artery to be occluded, and the involvement of the important perforating arteries.