Abstract
The natural history and long-term outcome of an intracranial dissecting aneurysm is not well known, and this study was initiated to elucidate these issues. Fifty patients with an intracranial dissecting aneurysm of the vertebrobasilar system were retrospectively analyzed with regard to their clinical features, angiographical findings, and their outcomes at six months and over a long term after onset of the aneurysm. Patients were divided into two groups : a subarachnoid hemorrhage (SAH) group (38 patients) ; and a non-SAH group that manifested ischemia and/or a headache (12 patients). The mean long-term follow-up period was 6.2 years. In the non-SAH group, the patients were younger and males predominated. In the SAH groups, the dissecting aneurysms were located more commonly at right vertebral artery. In both groups, the pearl and string sign was the most common finding on initial angiography. On follow-up angiography, an improvement in the arterial configuration was more frequently seen in the non-SAH group. The clinical features and the angiographical findings differed between the groups. In the SAH group, 27 patients (71%) were surgically treated, whereas in the non-SAH group, only 3 patients (25%) underwent surgery. In the SAH group, the six-month outcomes varied but correlated well with the clinical severity [Hunt and Kosnik grade] on admission. In the non-SAH group, the six-month outcomes were generally satisfactory, and the long-term outcomes were also favorable, with all patients, excepting one, having returned to work on long-term follow-up investigation. Based on their findings, they stress that surgical intervention should be decided prudently, because conservative treatment resulted in the successful recovery of many patients, even those with a subarachnoid hemorrhage.
