Medical and surgical management of intracranial aneurysms.

OBJECTIVE: To examine the medical and surgical aspects of intracranial aneurysms, including the pathogenesis, clinical manifestations, management of subarachnoid hemorrhage (SAH), and indications for surgical intervention.
DESIGN: This review presents the classification of intracranial aneurysms, defines specific aneurysms, and analyzes the Mayo Clinic experience with surgical treatment of cerebral aneurysms.
MATERIAL AND METHODS: Intracranial aneurysms are classified by cause, size, site, and shape. The clinical grading systems for SAH, the most common manifestation, are as follows: modified Botterell, Hunt and Hess, and World Federation of Neurological Surgeons. Surgical options are direct clipping, interventional neuroradiologic treatment, proximal ligation or trapping of aneurysms, and wrapping or coating of aneurysms. Although the timing of surgical intervention after SAH is controversial, it should be based on the clinical grade, site of the aneurysm, and patient's medical condition.
RESULTS: The frequency of intracranial aneurysms is estimated to be 1 to 8% in the general population, and 90% of patients have SAH. After SAH, 8 to 60% of patients die before they get to a hospital. After hospitalization, the mortality rate is 37%, severe disability is 17%, and outcome is favorable in 47%. The current trend for surgical treatment is early after SAH. The Mayo Clinic experience with 1,947 patients who underwent surgical treatment because of aneurysmal SAH or for aneurysmal repair between 1969 and 1990 is as follows: 1,445 had an excellent outcome, 231 had a good outcome, 171 had a poor outcome, and 100 died.
CONCLUSION: Aggressive management can be beneficial for many patients with severe neurologic injury after SAH by preventing rerupture of the aneurysm, attenuating the severity and sequelae of vasospasm, and decreasing the surgical complications.