Aneurysms of the vertebro-basilar system: clinical analysis and follow-up results.

336 cerebral aneurysms were treated during the past 18 years. Amongst these, 30 patients harboured aneurysms in vertebro-basilar circulation and form the subject material to be analysed. 17 were non-surgically treated whilst 13 cases received surgical treatment. In the group of non-surgical treatment, 6 were found in a moribund stage on admission, 9 had rebled during hospitalization and died. 2 other patients with large or giant aneurysms were treated palliatively and conservatively. They still survived over 18 months, 12 aneurysms were surgically clipped and 1 was wrapped with muscle. 2 of them died 1 week postoperatively due to pulmonary embolism. Risk factors are discussed. In contrast to the aneurysms of other circulatory territories vertebro-basilar aneurysms should be operated at the earliest possible opportunity; waiting does not provide an additional advantage to offset the risk of high mortality and morbidity after recurrent haemorrhage and vasospasm in this region.