Retinal and cerebral microembolization during coronary artery bypass surgery: a randomized, controlled trial.
BACKGROUND
We sought to compare the effects on ophthalmic function of coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) and off-pump (OPCAB) grafting and to investigate whether retinal microvascular damage is associated with markers of cerebral injury.


RESULTS
Retinal microvascular damage was assessed by fluorescein angiography and color fundus photography. Ophthalmic function was tested by the logarithm of the minimum angle of resolution visual acuity (VA), and cerebral injury, by transcranial Doppler ultrasound-detected emboli and S100 protein values. Twenty patients were randomized. Fluorescein angiography and postoperative VA could not be obtained for 1 CABG-CPB patient. Retinal microvascular damage was detected in 5 of 9 CABG-CPB but in none of 10 OPCAB patients (risk difference, 55%; 95% confidence interval [CI], 23% to 88%; P=0.01). Color fundus photography detected microvascular damage in 1 CABG-CPB patient but in no OPCAB patients; this lesion was associated with a field defect, which remained after 3 months of follow-up. There was no difference in postoperative VA. Doppler high-intensity transient signals (HITS) were 20.3 times more frequent in the CABG-CPB than in the OPCAB group (95% CI, 9.1 to 45; P<0.0001). Protein S100 levels were higher in the CABG-CPB than in the OPCAB group 1 hour after surgery (P<0.001). HITS were 14.7 times more frequent (95% CI, 3.5 to 62; P=0.001) and S100 level 2.1 times higher (95% CI, 1.3 to 3.5; P=0.005) when retinal microvascular damage was present.


CONCLUSIONS
The relative frequency of retinal microvascular damage between groups shows the extent to which the risk of cerebral injury is reduced with OPCAB. Imaging of part of the cerebral circulation provides evidence to validate markers of cerebral injury.
Ascione
Raimondo
R
Bristol Heart Institute, University of Bristol, Bristol, England.
Ghosh
Arup
A
Reeves
Barnaby C
BC
Arnold
John
J
Potts
Mike
M
Shah
Atul
A
Angelini
Gianni D
GD
D000368:Aged; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000379:methods*; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects; D004617:Embolism / Q000209:etiology*; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D020766:Intracranial Embolism / Q000209:etiology*; D008297:Male; D008833:Microcirculation / Q000473:pathology*; D008875:Middle Aged; D012171:Retinal Vessels / Q000473:pathology*; D009418:S100 Proteins / Q000097:blood; D018608:Ultrasonography, Doppler; D014792:Visual Acuity
D009418:S100 Proteins