Retinal and cerebral microembolization during coronary artery bypass surgery: a randomized, controlled trial

Area of Science:

• Cardiovascular Surgery
• Ophthalmology
• Neurology

Background:

• Coronary artery bypass grafting (CABG) can be performed with or without cardiopulmonary bypass (CPB).
• Potential ophthalmic and neurological complications associated with CABG, particularly CPB, warrant investigation.
• Retinal microvascular damage may serve as an indicator of cerebral injury.

Purpose of the Study:

• To compare the effects of on-pump (CABG-CPB) versus off-pump (OPCAB) coronary artery bypass grafting on ophthalmic function.
• To investigate the association between retinal microvascular damage and markers of cerebral injury after CABG procedures.

Main Methods:

• A randomized trial comparing CABG-CPB and OPCAB in 20 patients.
• Assessment of retinal microvascular damage using fluorescein angiography and color fundus photography.
• Ophthalmic function evaluated by visual acuity (VA); cerebral injury assessed by transcranial Doppler-detected emboli (high-intensity transient signals - HITS) and S100 protein levels.

Main Results:

• Retinal microvascular damage occurred in 5 of 9 CABG-CPB patients versus none of 10 OPCAB patients (P=0.01).
• HITS were significantly more frequent (20.3 times) and S100 protein levels were higher in the CABG-CPB group.
• Retinal microvascular damage was associated with more frequent HITS and higher S100 levels.

Conclusions:

• OPCAB surgery is associated with a significantly lower incidence of retinal microvascular damage compared to CABG-CPB.
• The findings suggest that OPCAB reduces the risk of cerebral injury.
• Imaging of retinal microvasculature can help validate markers of cerebral injury in cardiac surgery patients.