Deep Hypothermia With Retrograde Cerebral Perfusion Versus Moderate Hypothermia With Antegrade Cerebral Perfusion for Arch Surgery

Background. Patients undergoing aortic arch replacement are at high risk for neurologic injury. This study compared two different established neuroprotective strategies in patients undergoing elective transverse hemiarch replacement. Methods. Twenty patients undergoing hemiarch replacement were prospectively randomized to receive deep hypothermic circulatory arrest with retrograde cerebral perfusion (DHCA+RCP) or moderate hypothermic circulatory arrest with antegrade cerebral perfusion (MHCA+ACP). All patients received neurologist-adjudicated examinations and magnetic resonance imaging before discharge. The primary end point was a composite of stroke, transient ischemic attack, and magnetic resonance imaging-adjudicated injury. Secondary end points were transient neurologic dysfunction, and the National Institutes of Health Stroke Scale, and neurocognitive scores. Results. Randomization resulted in 11 DHCA+RCP patients and 9 MHCA+ACP patients. There was no difference in cardiopulmonary bypass, cross-clamp, or circulatory arrest times. MHCA+ACP patients underwent circulatory arrest at significantly warmer temperatures (26.3 degrees +/- 1.8 degrees C) than DHCA+RCP patients (19.9 degrees +/- 0.1 degrees C, p < 0.0001). There were no deaths or renal failure in either group. There was 1 stroke in each group. National Institute of Health stroke scale scores and neurocognitive test results were equivalent. Diffusion-weighted magnetic resonance imaging demonstrated lesions in 100% (9 of 9) of MHCA+ACP patients compared with 45% (5 of 11) of DHCA+RCP patients (p < 0.01). MHCA+ACP patients had a significantly higher number of lesions than DHCA+RCP patients (p < 0.01). The primary end point was achieved in 100% of MHCA+ACP patients compared with 45% of DHCA+RCP patients (p < 0.01). Conclusions. Although there was no significant difference in clinically evident neurologic injury, this pilot study suggests that MHCA+ACP may be associated with a higher incidence of radiographic neurologic injury than DHCA+RCP in patients undergoing elective hemiarch replacement. (C) 2019 by The Society of Thoracic Surgeons