Early vs. delayed cerebral infarction after aneurysm repair after subarachnoid hemorrhage.

BACKGROUND: Cerebral infarction is a major contributor to poor outcome after subarachnoid hemorrhage (SAH). Although usually considered a complication of delayed cerebral ischemia, infarcts may also occur early, in relation to initial brain injury or aneurysm-securing procedures.
OBJECTIVE: We analyzed the relative frequency and volume of early vs delayed infarcts after SAH and their relationship to hospital outcome.
METHODS: Retrospective review of consecutive patients admitted with aneurysmal SAH over 4 years who had follow-up brain imaging 7 days or later after admission. Imaging 24 to 48-hours after aneurysm-securing procedures was reviewed to classify infarcts seen on final imaging as early or delayed. Infarct volumes were measured by perimeter tracing and infarct burden calculated for each patient.
RESULTS: Of 250 eligible patients, 205 had follow-up imaging; infarcts were present in 61 patients. Of these, 29 had early infarcts, 16 had delayed infarcts, and 5 had both early and delayed infarcts. Eleven patients with infarcts did not undergo postprocedure computed tomography; these were presumptively classified as having late infarcts. Early and delayed infarcts contributed equally to infarct burden. Early infarcts were associated with aneurysm clipping (odds ratio: 4.2, 95% confidence interval: 1.8-9.5 compared with coiling), whereas delayed infarcts were almost always seen in association with angiographic vasospasm (odds ratio: 3.3, 95% confidence interval: 1.5-7.3). Patients with early as well as late infarcts, especially those with infarct burden more than 30 cm had worse hospital discharge disposition.
CONCLUSION: Early infarction occurs frequently after SAH and contributes as much as delayed cerebral ischemia to infarct burden and hospital outcome. Efforts to better understand and modify contributors to early infarction appear warranted.