Safety and limitations of line pressure-targeted cerebral perfusion strategy in aortic arch surgery.

Objectives: The optimal flow rate for selective antegrade cerebral perfusion during aortic arch surgery is unknown. While 10-15 ml/kg/min is generally recommended, our centre has adopted a line pressure-targeted, relatively low-flow antegrade cerebral perfusion strategy. We aimed to evaluate the effect of flow rate on neurological outcomes.

Methods: Patients without preoperative neurological deficits who underwent aortic arch surgery between January 2018 and May 2023 were enrolled. Under moderate hypothermia, an initial cerebral ischaemia period of 15-20 min was permitted. Following a brief retrograde cerebral perfusion, bilateral selective antegrade cerebral perfusion was performed using balloon-tipped perfusion catheters. The flow rate was determined using a line pressure of 200 mmHg. Risk factor analysis for postoperative permanent and temporary neurological deficits was conducted.

Results: A total of 262 patients were included. The median selective antegrade cerebral perfusion flow rate was 5.7 ml/kg/min. Permanent neurological deficits occurred in 2 patients (0.8%), while temporary neurological deficits occurred in 30 patients (11.5%). The low antegrade cerebral perfusion flow rate was not a risk factor for permanent or temporary neurological deficits. Prolonged cerebral ischaemia time was the only significant risk factor for temporary neurological deficits.

Conclusions: Under moderate hypothermia and with the assistance of retrograde cerebral perfusion, the line pressure-targeted, relatively low-flow selective antegrade cerebral perfusion strategy at our centre achieved favourable neurological outcomes. However, prolonged cerebral ischaemia time was a significant risk factor for temporary neurological deficits.