Bilateral monitoring of the cerebral oxygen saturation in aortic arch surgery

Cerebral ischemia with consecutive neurological damage is a typical complication in aortic arch surgery. Therefore, intraoperative neuromonitoring is of increasing interest This paper describes the role of bilateral near-infrared-spectroscopy (NIRS) in detecting cerebral ischemia. In the case of a patient with acute aortic dissection (Daily,, type A), an unexpected sudden reduction of perfusion of the right carotid artery could easily be detected with the help of two instruments INVOS 3100A. The decrease in the saturation values from 74% to 54% correlated well with the drop of blood pressure in the right radial artery. Clamping of the aorta with interruption of the blood flow into the innominate artery through the false lumen was the reason for the low cerebral perfusion. After repositioning the aortic clamp NIRS in combination with invasive blood pressure monitoring sufficiently allowed to control the further course of cerebral perfusion. The NIRS is a non-invasive, easy to handle, and easy to interpret method for intraoperative monitoring of the neurological status. Therefore in our opinion it has got some relevant advantages in contrast to other neuromonitoring methods in aortic arch surgery.