Aneurysmal subarachnoid hemorrhage: timing of surgery and mortality.

In contrast to the incidence of other types of stroke, the incidence of aneurysmal subarachnoid hemorrhage has not changed. It is highest in the oldest age groups, and this indicates that it is not due to a congenital lesion. The primary factors that affect survival after aneurysmal subarachnoid hemorrhage are the clinical grade of the patient and the duration of time from onset to the time the patient is seen for medical attention. Because of the very high early mortality from aneurysmal subarachnoid hemorrhage, surgeons generally wait until 10 to 14 days before undertaking surgery. This delay results in a lower surgical mortality but makes it difficult to show an effect on overall mortality. Increasing attention is being given to early surgery after aneurysmal subarachnoid hemorrhage.