Evaluation of brain oxygenation during selective cerebral perfusion by near-infrared Spectroscopy

Background. Although selective cerebral perfusion (SCP) has been used for cerebral protection in aortic arch operations, the appropriate perfusion conditions of SCP are unclear. Methods. We used near-infrared spectroscopy, which evaluates brain ischemia noninvasively and continuously, to determine whether perfusion with SCP (core temperature, 20°C; flow rate, 10 mL · kg−1 · min−1) was acceptable in terms of oxyhemoglobin and deoxyhemoglobin in patients having SCP for aortic arch operations (SCP group, n = 6) versus patients having cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CPB group, n = 6). Results. There were no significant differences in age (65 ± 10 versus 63 ± 12 years), CPB time (199 ± 67 versus 199 ± 52 minutes), changes in hematocrit (-12.9% ± 3.7% versus -12.5% ± 6.0%), lowest blood pressure (43 ± 7versus 45 ± 10 mm Hg), or highest central venous pressure (8 ± 2 versus 9 ± 4 mm Hg) between the SCP and CPB groups. In the SCP group, the maximum decrease in oxyhemoglobin level and the maximum increase in deoxyhemoglobin level were −5.0 to −11.4 μmol/L and −0.1 to 3.9 μmol/L, respectively; in the CPB group, the respective changes were −3.2 to −14.2 μmol/L and −0.4 to 3.6 μmol/L. Changes of oxyhemoglobin and deoxyhemoglobin levels in the SCP group were almost within the range of those in the CPB group. There were no brain complications in either group. Conclusions. As described here, SCP is acceptable and safe for brain protection in aortic arch procedures.