Surgical management of unruptured intracranial aneurysms.

The surgical management of patients with unruptured intracranial aneurysms continues to be controversial. The criteria for withholding treatment or choosing between endovascular embolization and conventional microsurgery are not well delineated. The present study analyzes the morbidity and mortality that can be expected with modern surgical management of unruptured aneurysms, and therefore serves as a point of reference for clinical decision-making in this group of patients. A total of 202 consecutive operations for attempted clipping of unruptured intracranial aneurysms are reported. Subarachnoid hemorrhage from another aneurysm was the most common presentation (55 cases). Thirty-seven patients presented with headache, 36 with mass effect from the aneurysm, and 19 with embolic events; 11 aneurysms were associated with an arteriovenous malformation, 10 caused seizures, and 34 were incidental findings. Excellent or good outcome was achieved in 100% of patients with aneurysms less than 10 mm in diameter, 95% with aneurysms 11 to 25 mm, and 79% with aneurysms greater than 25 mm. Except for giant basilar aneurysms, size (and not location) of the aneurysm was the key predictor of risk for surgical morbidity. These data may be useful when discussing with patients the risk:benefit ratio of choosing between conservative management, endovascular embolization, and microsurgical clipping.