Controversy remains regarding the optimal neuroprotection strategy for elective hemiarch replacement (HEMI). This study sought to compare outcomes in patients who underwent HEMI utilizing the 2 most common contemporary methods of cerebral protection.

The ARCH international aortic database was queried, and 782 patients undergoing elective HEMI with circulatory arrest from 2007 to 2012 were identified. There were 418 patients who underwent HEMI using moderate hypothermia (nasopharyngeal temperature 20.1 to 28.0 °C) and antegrade cerebral perfusion (MHCA/ACP). There were 364 patients who underwent HEMI using deep hypothermia (nasopharyngeal temperature 14.1 to 20 °C) and retrograde cerebral perfusion (DHCA/RCP). Adverse outcomes were compared between the groups using both univariable and multivariable analyses.

Patients who underwent MHCA/ACP were older (64 vs 61 years, P = 0.01) and more frequently had peripheral vascular disease than DHCA/RCP patients (28.5% vs 7.1%, P < 0.001). Patients in the DHCA/RCP group had a greater incidence of full aortic root replacement (55.8% vs 26.4%, P < 0.001) and more frequently had a central cannulation strategy (83% vs 55.7%, P < 0.001). Cardiopulmonary bypass (170 vs 157 min, P = 0.002) and aortic cross-clamp (134 vs 92 min, P < 0.001) times were significantly longer in the DHCA/RCP group. On univariable analysis, overall mortality was statistically similar between groups (MHCA/ACP 3.4% vs DHCA/RCP 2.3%, P = 0.47), but permanent neurologic deficits were significantly lower in the DHCA/RCP cohort (MHCA/ACP 3.9% vs DHCA/RCP 1.0%, P = 0.02). Multivariable analysis showed no difference in mortality nor perioperative stroke between perfusion cohorts.

Both MHCA/ACP and DHCA/RCP are excellent neuroprotective strategies that produce low mortality in patients undergoing elective HEMI. DHCA/RCP may demonstrate theoretically improved neurologic outcomes compared with MHCA/ACP, but this topic warrants further study.