Unruptured intracranial aneurysms: an assessment of the annual risk of rupture based on epidemiological and clinical data.
From autopsy and neuroradiological studies a maximum prevalence of unruptured intracranial aneurysms (UA) of 0.5% in the general population is revealed. Studies concerning the incidence of aneurysmal subarachnoid haemorrhage (SAH) revealed 10 cases per 100,000 inhabitants per year. From these epidemiological parameters a minimum annual risk of 2% of rupture of an UA is calculated. It is in accordance with clinical studies, which also demonstrated an annual risk of UA rupture of at least 2%. No critical size of the UA predisposing to rupture has been found. Operation on diagnosed UA is recommended because of the serious prognosis after aneurysmal SAH (morbidity 20%-25% and mortality 50%-60%) and because the morbidity (4%) and the mortality (0%) after operative treatment of UA are very low.
Rosenørn
J
J
University Clinics of Neurosurgery, Copenhagen County Hospital, Glostrup, Denmark.
Eskesen
V
V
Schmidt
K
K
D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000453:epidemiology / Q000601:surgery; D012307:Risk Factors; D012422:Rupture, Spontaneous / Q000453:epidemiology; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology