Risks of surgery for unruptured intracranial aneurysms.

A series is presented of 43 patients with multiple aneurysms and subarachnoid hemorrhage in whom a second operation was necessary in order to clip all the aneurysms. There was one surgical death due to coronary thrombosis and infarction which occurred 3 weeks after surgery, for a surgical mortality rate of 2.3%. One patient developed a permanent neurological deficit (hemiparesis and dysphasia). Thus, the surgical risks are smaller than the natural risk of bleeding and death from hemorrhage. Patients with any other serious illness increasing the surgical risk should not be subjected to an operation for an unruptured aneurysm; a second operation is indicated in all low-risk patients with multiple aneurysms or with incidentally identified aneurysms.