Moderate Versus Deep Hypothermic Circulatory Arrest for Elective Aortic Transverse Hemiarch Reconstruction

Abstract

Deep hypothermic circulatory arrest (DHCA) with retrograde cerebral perfusion (DHCA group) has traditionally been the cerebral protection strategy during transverse hemiarch aortic reconstruction. Recently, we have adopted moderate hypothermic (≥ 25 °C) circulatory arrest (MHCA) with antegrade cerebral perfusion (MHCA group). We compared the outcomes for these two circulatory arrest management strategies. From 2008 to 2012, in a concurrent series of 376 patients (DHCA, 301; MHCA, 75) undergoing transverse hemiarch for aortic aneurysm disease, incidences of concomitant root replacement (44% vs 47%, p = 0.8), and aortic valve replacement (29% vs 21%, p = 0.3) were similar, although atherosclerotic aneurysm pathology was present in patients in the MHCA group (71% vs 33%, p < 0.01). Antegrade cerebral perfusion was established via axillary artery or direct innominate artery cannulation. A database was prospectively maintained. MHCA group patients were older (66 ± 11 vs 60 ± 14 years; p < 0.01). Other demographics were similar. Aortic cross-clamp (128 ± 46 vs 163 ± 57 minutes, p < 0.01) and cardiopulmonary bypass (167 ± 49 vs 222 ± 61 minutes, p < 0.01) times were lower in the MHCA group. Transfusion requirements were significantly reduced with MHCA (38% vs 61%, p < 0.01), especially use of fresh frozen plasma and cryoprecipitate. Direct innominate artery cannulation did not result in any vascular or neurologic complication. Postoperative outcomes were similar. In-hospital and 30-day mortality was 1% in both groups. Stroke (0% vs 2%) and hemodialysis rates (0% vs 1%) were also similar. MHCA with antegrade cerebral perfusion yields excellent and equivalent outcomes to DHCA for elective aortic hemiarch reconstruction. MHCA significantly improves intraoperative times and, importantly, reduces transfusion requirements compared with DHCA with a retrograde cerebral perfusion strategy.