Optimizing selective cerebral perfusion: deleterious effects of high perfusion pressures

Area of Science:

• Cardiovascular Surgery
• Neuroprotection
• Cerebral Physiology

Background:

• Selective cerebral perfusion (SCP) is vital for neuroprotection during complex aortic surgery.
• Optimal SCP pressure for neuroprotection remains undetermined.
• This study investigates SCP pressure effects on cerebral physiology and outcomes.

Purpose of the Study:

• To determine the optimal perfusion pressure for selective cerebral perfusion during complex aortic surgery.
• To evaluate the impact of varying SCP pressures on cerebral blood flow, oxygen metabolism, and neurobehavioral outcomes.
• To identify potential associations between SCP pressure and cerebral injury.

Main Methods:

• Thirty piglets underwent cardiopulmonary bypass with SCP at 50, 70, or 90 mm Hg for 90 minutes.
• Cerebral blood flow and oxygen metabolism were measured using microspheres and sinus sampling.
• Neurobehavioral outcomes were assessed using visual evoked potentials and blinded videotaped analysis for 7 days.

Main Results:

• Higher SCP pressures (70-90 mm Hg) significantly increased cerebral blood flow but not cerebral oxygen metabolism.
• Group C (90 mm Hg) exhibited significantly higher intracranial pressure during SCP.
• Poorer neurobehavioral scores were observed in piglets receiving higher SCP pressures (70-90 mm Hg).

Conclusions:

• Selective cerebral perfusion at 50 mm Hg provides superior neuroprotection compared to higher pressures.
• Increased cerebral blood flow at higher SCP pressures correlates with cerebral injury markers.
• Lower SCP pressure (50 mm Hg) is recommended for improved neurobehavioral recovery in complex aortic surgery.