A Comparative Study of Different Hypothermic Circulatory Arrest Strategies on Aortic Surgery.

A Comparative Study of Mild Hypothermic Circulatory Arrest Versus Moderate Hypothermic Circulatory Arrest on Aortic Surgery.

By comparing the clinical outcome of patients underwent different hypothermic circulatory arrest (mild hypothermic versus moderate hypothermic) during aortic arch surgery, this study aims to determine the optimal hypothermic circulatory arrest strategy for aortic surgery.

Hypothermic circulatory arrest (HCA) is the cornerstone of aortic surgery. It provides a bloodless and still operative field. But the side effect of hypothermia also draws people's concern. With the development of surgical techniques and cardiopulmonary bypass (CPB) management, the temperature of HCA has been raised from deep hypothermia (14.1-20 degree) to moderate hypothermia (20.1-28 degree), and it has been a primary choice for many surgeons around the world. Some of surgeons still tried to push the limit and started using mild hypothermia (28.1-34 degree), and satisfactory outcome was obtained. However, the optimal temperature of HCA has not yet been determined.

In this randomized controlled study, 80 informed and consenting patients who are scheduled for total arch replacement with concomitant proximal aortic reconstruction will be randomized to mild (28.1-34 degree) or moderate (20.1-28 degree) hypothermia during circulatory arrest. Clinical outcomes of both groups will be analyzed to determine the optimal temperature for HCA.

Inclusion Criteria:

1.Patients with confirmed diagnosis (i.e.aortic dissection, marfan syndrome, aortic arch aneurysm and so on), which require total aortic arch replacement.

Exclusion Criteria:

1. Preoperative heart attack or coma.
2. Patients with surgical contraindication, including but not limited to severe cardiac,pulmonary,renal or hepatic insufficiency.
3. Pre-existing heart condition or neurological disease.
4. Variation of aortic arch or its branch vessels.
5. Patient is currently on anticoagulation therapy or has other medical condition that compromises the coagulation.
6. Patient with active infection.
7. Allergy to anaesthetic or contrast agent.
8. Pregnant or lactating female.
9. Patient is already on other medical trial.
10. Other medical, psychological or socioeconomics condition determined by investigator that is not eligible for the study.