Surgical technique:
Proximal right brachial artery cannulation with unilateral ASCP and 28°C
hypothermia was used in all patients 9. Back bleeding
from left carotid artery was always controlled to test the adequacy of
collateral flow from the right carotid system. During ASCP 700-800
ml/min (10 ml/kg/min) blood flow was provided with cerebral NIRS
monitoring (right and left frontal regions). If ASCP period was
anticipated to last longer than 40-45 minute or a difference between
right and left cerebral NIRS values with more than 20% drop from the
baseline was observed bilateral perfusion was employed through a
separate left carotid artery cannula which was necessary in 3 patients.
For spinal cord rSO2 NIRS monitoring pallets were placed
at the skin over spinous process of 5th and
10th thoracic vertebrae level. Baseline measurement of
NIRS value (rSO2) were done before anesthetic induction
and then followed by 5 periods of evaluation; after anesthetic
induction, upon commencement of cardiopulmonary bypass (CPB), after
cross clamp application, at the end of ASCP period and after conclusion
of CPB (SOMANETICS INVOSTM 7100 Cerebral/Somatic
Oximeter, Medtronic).