SAN FRANCISCO — Late neurocognitive deficits after coronary artery bypass graft surgery are markedly decreased through the use of reduced aortic manipulation techniques during the operation, according to the findings presented at the annual meeting of the American Association for Thoracic Surgery.
Dr. John W. Hammon reported on 83 patients undergoing CABG with cardiopulmonary bypass who were randomized to traditional multiple-aortic clamping or a single aortic clamp that's softer and produces less force on the vessel. A total 74 patients undergoing OPCAB served as controls.
At 6 months, new neurocognitive deficits were present in 30% of the single-cross-clamp group, 32% of the OPCAB patients—and in 57% of the multiple-cross-clamp group.
The hospital mortality rate was 4% in the multiple-cross-clamp group, compared with 1% in each of the other study arms.
One patient in each group had an acute stroke upon awakening from anesthesia. Two each in the multiple and single-cross-clamp groups experienced late strokes.
OPCAB patients were significantly younger and had fewer comorbidities than the on-pump patients. They also had fewer emboli in their left carotid artery by ultrasound examination, less reinfused shed blood, and a shorter mean length of hospital stay. All of this led some audience members to express surprise that the OPCAB group didn't have a lower late neurocognitive deficit rate than the single-aortic-cross-clamp patients.
Dr. Hammon suggested that cerebral hypoperfusion may have occurred in the OPCAB patients when surgeons lifted the heart to perform posterior anastomoses.