Occlusion of Intracranial Aneurysms by Ferromagnetic Thrombi

Abstract

The rupture of intracranial aneurysms is a major cause of strokes, but present operations to repair aneurysms and to prevent their recurrent rupture are plagued by high morbidity and mortality rates. A simpler and safer operation is proposed utilizing two permanent magnet‐tipped probes introduced through a small opening in the skull and guided under x‐ray control to lie near the aneurysm. The magnets attract ferromagnetic emboli injected into the cerebral circulation through the internal carotid artery in the neck, eventually filling the aneurysm. Following the formation of a blood clot which would reinforce the aneurysm wall against rupture, the probes would be withdrawn. Simulated aneurysms were occluded with three‐micron carbonyl‐iron particles injected upstream from two 5‐mm‐diameter, bullet‐shaped Alnico V magnets applied at the aneurysmal opening. The same particles injected into the intracranial circulation of animals did not obstruct the capillaries and produced no detectable clinical, physiologic, or pathologic changes in the brains. A clinical trial using this technique was successful in occluding an aneurysm in a patient.