Is More than One Hour of Selective Antegrade Cerebral Perfusion in Moderate-to-Mild Systemic Hypothermic Circulatory Arrest for Surgery of Acute Type A Aortic Dissection Safe?

Abstract

Objectives: Surgery for acute type A aortic dissection (AAD) remains a surgical challenge with considerable risk of morbidity and mortality. Antegrade cerebral perfusion (ACP) has been popularized, offering a more physiologic method of brain perfusion during complex aortic arch repair, often necessary in setting of AAD. The safe limits of this approach under moderate-to-mild systemic hypothermic circulatory arrest (≥ 28°C) are yet to be defined. Thus, the current study investigates our clinical results after surgical treatment for AAD in patients with a selective ACP and systemic circulatory arrest time of ≥ 60 minutes in moderate-to-mild hypothermia (≥ 28°C).

Methods: Between January 2000 and April 2016, 63 consecutive patients underwent surgical treatment for AAD employing selective ACP during moderate-to-mild systemic hypothermia (≥ 28°C) with prolonged ACP and circulatory arrest times. Patients' mean age was 59 ± 15 years, and 39 patients (62%) were men. Hemiarch replacement and total arch replacement were performed in 13 (21%) and 50 (79%) patients, respectively. Frozen elephant trunk, arch light, and elephant trunk technique were performed in nine (14%), six (10%), and three patients (5%), respectively. Clinical data were prospectively entered into our institutional database. Mean late follow-up was 6 ± 4 years and was 98% complete.

Results: Cardiopulmonary bypass time accounted for 245 ± 81 minutes and the myocardial ischemic time accounted for 140 ± 43 minutes. Mean duration of ACP was 74 ± 12 minutes. The mean lowest core temperature accounted for 28.9 ± 0.8°C. Unilateral ACP was performed in 44 patients (70%); bilateral ACP was used in the remaining 19 patients (30%). Intensive care unit stay reached 6 ± 5 days. New onset of acute renal failure requiring hemofiltration was observed in 8% of patients (n = 5). New postoperative permanent neurologic deficits were found in five patients (8%) and transient neurologic deficits in six patients (10%). There was one case of paraplegia. Thirty-day mortality and in-hospital mortality were 8 (n = 5) and 11% (n = 7), respectively. Overall survival at 5 years was 76 ± 9%.

Conclusion: Our preliminary data suggest that selective ACP during moderate-to-mild systemic hypothermic circulatory arrest (≥ 28°C) can safely be applied for more than 1 hour even in the setting of AAD.