A functional evaluation of cerebral perfusion for coronary artery bypass grafting patients

Area of Science:

• Cardiovascular Surgery
• Neurology
• Medical Imaging

Background:

• Perioperative stroke is a significant risk in patients undergoing coronary artery bypass grafting (CABG), particularly those with pre-existing cerebral hypoperfusion.
• Cerebral hypoperfusion can be identified using single-photon emission-computed tomography (SPECT) in conjunction with cerebral magnetic resonance angiography (MRA).

Purpose of the Study:

• To evaluate the effectiveness of maintaining pulsatile blood flow via off-pump CABG or intra-aortic balloon pumping (IABP) in preventing perioperative stroke in patients with cerebral hypoperfusion.
• To determine the importance of functional evaluation of cerebral perfusion using SPECT in patients with significant craniocervical vessel stenosis.

Main Methods:

• A retrospective analysis of 286 patients undergoing isolated CABG between 2006 and 2015 with cerebral MRA.
• Patients with significant craniocervical stenosis (n=75) underwent cerebral SPECT, categorized into normal perfusion (NP) and hypoperfusion (HP) groups.
• Comparison of stroke rates between the HP group, NP group, and a control group with no significant stenosis.

Main Results:

• No strokes occurred in the cerebral hypoperfusion (HP) group.
• One stroke occurred intraoperatively in the control group, and 3 postoperative strokes within 30 days in the control group; differences were not statistically significant.
• Long-term stroke-free rates did not significantly differ between the HP and control groups.

Conclusions:

• Functional evaluation of cerebral perfusion by SPECT is crucial for patients with significant stenotic lesions on cerebral MRA.
• Maintaining adequate pulsatile flow through off-pump CABG or IABP with conventional CABG is a viable strategy to prevent perioperative stroke, even in the presence of detected cerebral hypoperfusion.