The purpose of this trial is to determine whether aortic manipulation in patients undergoing
coronary bypass graft surgery leads to increased incidence of microemboli and subsequent
impairment of neurobehavioral function.
Patients who have coronary artery bypass graft (CABG) surgery must have their aorta (the
large blood vessel that is attached to the heart) clamped with an instrument. There are two
basic ways of manipulating the aorta during surgery. One way is to place a single clamp
across the aorta. The other way is to place more than one clamp on the aorta in several
places. Both methods are used, but it is not known if one way is better than the other.
The purpose of this study is to compare the two methods of clamping to see if one way is
better than the other, and to determine whether patients who undergo reduced manipulation of
the aorta have fewer microemboli delivered to the brain during CABG surgery and have a lower
incidence of neurobehavioral problems following surgery. Microemboli are tiny fat particles
that enter the bloodstream during surgery, circulate to the brain, and block tiny blood
vessels, causing brain deficits.
Participants in this trial will be randomly classified into one of two groups: the
experimental group will undergo cross clamping of the aorta with a single clamp and be given
retrograde cardioplegia for heart protection, and the control group will undergo cross
clamping of the aorta with multiple clamps and be given antegrade cardioplegia for heart
protection. Neurobehavioral assessments will be accomplished with a comprehensive battery of
neurological and neuropsychological tests.
- Participants must be English-speaking patients,
- 50 years of age or older, and
- undergoing elective CABG surgery.
- Participants of both genders and all races are eligible.