Embolic stroke is a feared complication after open heart surgery. Many patients undergo testing of the carotid arteries before surgery, but intracranial atherosclerosis is not commonly assessed as a mechanism.

We reviewed a prospectively maintained database of all open heart surgeries at our institution from 2005 to 2007 for patients who developed a periprocedural ischemic stroke. These patients were assessed for the mechanism of stroke through radiographic imaging of the intracranial circulation to determine the frequency of intracranial atherosclerosis as a mechanism for perioperative stroke.

A total of 10,367 patients underwent open heart surgery from 2005 to 2007 and 180 (1.74%) patients were noted to have an ischemic stroke. Of the 180 patients, 98 (55%) underwent intracranial imaging and 29 (30%) were noted to have narrowing of an intracranial vessel. Seventeen (17.4%) patients were found to have infarct ipsilateral to the stenosis, but 8 (8.1%) of these patients were also noted to have infarcts in other vascular territories. Thus, 9 (9.1%) patients were thought to have a stroke solely related to the intracranial stenosis.

Intracranial atherosclerosis may be an underreported mechanism for perioperative stroke after open heart surgery. Further study is required to better understand the prevalence of the disease in this population and subsequent risk of stroke.