Treatment of mycotic intracranial aneurysms

Two patients with mycotic intracranial aneurysms were successfully treated with only antibiotic therapy. One patient, who had subacute bacterial endocarditis, rheumatic valvular disease, and an abscessed tooth, sustained a subarachnoid hemorrhage from a ruptured right middle cerebral artery trifurcation aneurysm. The other patient, who had Turner's syndrome and probable congenital aortic stenosis, developed multiple neurological findings during an ipisode of acute bacterial endocarditis precipitated by an infected ingrown toenail; a false aneurysm of the distal left middle cerebral artery and two lesions involving the left superior cerebellar artery were found. A study of the literature shows that only 45 patients with mycotic intracranial aneurysms have received adequate antibiotic therapy and angiographic documentation. Statistically, there does not appear to be a clear-cut advantage to antibiotic plus surgical therpy over antibiotic alone. In fact, in 21 patients who underwent serial angiography, lesions were smaller in six and not visualized in 11. In four patients the aneurysms increased in size; in two others fresh lesions formed. The author proposes the following diagnostic and therapeutic regimen: 1) earliest possible diagnosis of the underlying disorder; 2) appropriate antibiotic therapy; 3) early four-vessel cerebral angiography and follow-up studies every 2 to 3 weeks; study; 5) definitive operation upon completion of antibiotic therapy if the lesion is larger or the same size; and 6) postoperative angiography to evaluate the effectiveness of treatment and to search for interim lesions.