SummaryMicroemboli during surgery have been hypothesized to cause postoperative cognitive changes. The purpose of this article was to systematically review the available literature related to intraoperative microemboli, measured with transcranial Doppler ultrasound and postoperative cognitive function. The literature remains largely undecided on the role of microemboli and cognitive impairment after surgery, because most studies underpowered to show a relationship.

Ischemic changes on MRI after CEA are related to postoperative MS.

Background and Purpose High-intensity transient signals detected by transcranial Doppler sonography have been associated with particulate cerebral emboli. Their clinical correlates are poorly understood. This study was undertaken to assess their relation to cerebral ischemia and to determine whether the severity of cerebral arterial stenosis has an impact on their occurrence.Methods We studied 96 arteries in 75 consecutive patients with extracranial or intracranial arterial lesions or potential cardiac sources of cerebral embolism. Sixty patients had histories of cerebral or retinal transient ischemic attacks or infarcts, and 15 were asymptomatic. The diagnosis of ischemia was based on the clinical presentation and was supported by extensive laboratory testing. A transcranial Doppler sonography unit equipped with special software for emboli detection was used. Signals were selected based on criteria established a priori.

In this retrospective study, microembolic signals were more common in the territories of symptomatic arteries and particularly those with severely stenotic lesions. During a short follow-up, recurrent ischemic events were more common along the territories of arteries with TCD-detected microembolism and previous symptoms of cerebral or retinal ischemia.

In this preliminary report, atherosclerosis in the carotid arteries, aorta, and coronary circulation is associated with the development of delirium after CABG surgery. Further investigation into atherosclerosis as a risk factor for delirium is warranted.