Effect of Deep Hypothermia Circulatory Arrest on Neurological Outcomes in Patients Undergoing Replacement of Ascending Aorta: A Comparison between Young and Elderly Adults

Objectives: Deep hypothermic circulatory arrest (DHCA) is used to avoid brain tissue injury during surgical replacement of ascending aorta. It is known that circulatory arrest is associated with high incidence of neurological adverse effect. Various studies were done to configure the relation between the DHCA and the postoperative neurological outcomes; however, the effect of DHCA on elderly patients is still not well clarified. The aim of this major study is to compare the neurological outcomes between young and elderly adults undergoing replacement of ascending aorta in DHCA.

Methods: We retrospectively analyzed 905 consecutive patients, who underwent replacement of ascending aorta using DHCA due to aneurysm or calcification between 2001 and 2015. Patients were divided into two groups: those aged 75 years and older (elderly group; 22.4%) and those younger than 75 years (younger group; 77.6%). Patients with type A-dissection of ascending aorta are excluded from the study.

Results: Comparing both groups, average age was 63.2 ± 10.2 vs 78.7 ± 3.0 years (p < 0.001). Elderly group had a significantly higher Euro-score II [26.7% (18.1;36.3) vs. 11.6% (7.4;19.9); p = < 0.001)]. Coronary heart disease was significantly higher in elderly group (49.8% vs. 35.6% p < 0.001) with more atrial fibrillation (23.6% vs. 16.4%; p = 0.018) compared with the younger group. Chronic renal failure was significantly more in elderly group (17.2% vs. 9.1%, p = 0.001) as well as type 2 Diabetes mellitus (16.3% vs. 10.7%; p = 0.031). Intraoperatively, DHCA time showed no variation [14 minute (12; 17) vs. 15 minute (12;18); p = 0.42]. Cardiopulmonary bypass time [139 minute (110; 183) vs. 144 minute (113;189); p = 0.225] and time of cross-clamping [91 minute (63;116) vs. 92 minute (65; 127); p = 0.348] were nearly similar in both groups. Postoperatively, a higher incidence of delirium was significantly reported in the older group (24.1% vs. 9.0%; p < 0.001). However, there was no reported significantly difference regarding neurologically complications between both groups. 30-day mortality was satisfactory for the elderly group, but significantly higher compared with the younger group (7.1% vs. 3.5% p = 0.031).

Conclusion: Our study concluded that surgical replacement of ascending aorta using deep hypothermia circulatory arrest can be applied safely on old aged patients without increasing risk of neurological complication. We encourage the usage of this technique in complexed surgical aortic Operation.