Evolving selective cerebral perfusion for aortic arch replacement: high flow rate with moderate hypothermic...

Area of Science:

• Cardiovascular Surgery
• Neurology
• Hypothermia

Background:

• Hypothermic circulatory arrest (HCA) with selective cerebral perfusion (SCP) is a safe strategy for aortic arch surgery.
• Optimal HCA temperature and SCP flow rates remain undetermined.
• This study investigated the impact of varying HCA temperatures on neurologic outcomes.

Purpose of the Study:

• To evaluate the effect of different hypothermic circulatory arrest (HCA) temperatures on neurologic complications during aortic arch surgery.
• To determine if increasing HCA temperature to 28°C, combined with selective cerebral perfusion (SCP), impacts neurologic outcomes.

Main Methods:

• 229 patients undergoing aortic arch replacement with HCA and SCP were divided into three groups based on HCA temperature: 20°C (Group A), 25°C (Group B), and 28°C (Group C).
• SCP flow rates were adjusted: ~10 mL/kg/min for Groups A and B, and ~15 mL/kg/min for Group C.
• Neurologic complications, early mortality, and duration of HCA and SCP were analyzed.

Main Results:

• No significant difference in early mortality (p=0.19) or postoperative stroke rates (p=0.55) was observed across the temperature groups.
• Postoperative transient neurologic dysfunction rates were similar across groups (p=0.54).
• Mean durations of circulatory arrest and SCP were significantly shorter in Groups B and C compared to Group A (p<0.0001 and p=0.0007, respectively).

Conclusions:

• Increasing HCA temperature to 28°C with a higher SCP flow rate is safe and does not increase postoperative neurologic events.
• Moderate HCA with SCP enables radical aortic arch reconstruction, potentially avoiding deep hypothermia.
• This approach offers a safe alternative for complex aortic arch surgeries.