Clinical efficacy of intermittent pressure augmented-retrograde cerebral perfusion

During aortic surgery under hypothermic circulatory arrest, retrograde cerebral perfusion (RCP) is commonly used as a cerebroprotective method to extend the duration of circulatory arrest safely. Kitahori and colleagues described a novel protocol of RCP using intermittent pressure augmented (IPA)-RCP in 2005. The aim of the present study was to determine the clinical effectiveness of this novel protocol.

A total of 20 consecutive patients undergoing total replacement of the aortic arch were assigned to a conventional RCP (n = 10) or an IPA-RCP group (n = 10). Cerebral perfusion was provided at a continuous venous pressure of 25 mm Hg in the conventional RCP, and venous pressure was intermittently provided at 20 mm Hg for 120 seconds and at 45 mm Hg for 30 seconds in the IPA-RCP group. The clinical outcomes were compared between the 2 groups. Regional cerebral oxygen saturation (rSO(2)) was measured using near infrared spectroscopy every 10 minutes from the beginning of RCP initiation. To represent the brain oxygen consumption, the decline ratio of rSO(2) was calculated.

There was no surgical mortality or major neurologic complications in either group. The interval from the end of surgery to full wakefulness was significantly shorter in the IPA-RCP group (85 ± 64 minutes) than in the conventional RCP group (310 ± 282 minutes; P < .05). Although the initial rSO(2) value did not show significant difference in both groups, the rSO(2) with IPA-RCP was greater than that with conventional RCP from 10 to 70 minutes (P < .05). The decline ratio of rSO(2) was lower in the IPA-RCP group than in the RCP perfusion group at all points (P < .05).

IPA-RCP might provide more homogenous cerebral perfusion and a more effective oxygen supply to the brain with better clinical results than conventional RCP.