CEREBRAL ISCHEMIC DISORDERS AND CEREBRAL OXYGEN BALANCE DURING CARDIOPULMONARY BYPASS-SURGERY - PREOPERATIVE EVALUATION USING MAGNETIC-RESONANCE-IMAGING AND ANGIOGRAPHY
T. Goto et al., CEREBRAL ISCHEMIC DISORDERS AND CEREBRAL OXYGEN BALANCE DURING CARDIOPULMONARY BYPASS-SURGERY - PREOPERATIVE EVALUATION USING MAGNETIC-RESONANCE-IMAGING AND ANGIOGRAPHY, Anesthesia and analgesia, 84(1), 1997, pp. 5-11
We compared the preoperative prevalence of small cerebral infarctions
and carotid stenosis to jugular venous oxygen saturation (Sjvo(2)) dur
ing coronary artery bypass grafting (CABG). Sjvo(2) served as an indic
ator of whether cerebral oxygen supply meets demand in patients on car
diopulmonary bypass (CPB). The study population consisted of 121 patie
nts who were either older than 65 yr or had a history of cerebrovascul
ar disease. The patients underwent preoperative cerebral magnetic reso
nance imaging (MRI) and cervical magnetic resonance angiography (MRA)
to detect small cerebral infarctions and carotid artery stenosis. Pati
ents with atherosclerosis of the ascending aorta were identified by in
traoperative epiaortic ultrasonography. Liberation of emboli from the
aorta in these patients was prevented by modification of the standard
operation. From preoperative MRI and MRA, 65 patients (54%) had small
cerebral infarctions in the white matter or basal ganglia and nine pat
ients (7%) demonstrated moderate or severe stenosis in the carotid art
eries. Thirteen patients (11%) had moderate or severe atheromatous dis
ease of the ascending aorta. The severity of aortic atherosclerosis wa
s significantly correlated with the grade of carotid stenosis (P < 0.0
5). In patients with small infarctions, Sjvo(2) was significantly lowe
r than in patients without infarctions (controls) at initiation of CPB
, 30 min after aortic cross-clamping, and during the rewarming period
of CPB (P < 0.05). Thus, small cerebral infarctions were not uncommon
in elderly patients undergoing CABG. Patients with small cerebral infa
rctions may be at risk for an imbalance in cerebral oxygen supply and
demand during the rewarming period because they are unable to deliver
the necessary compensatory blood flow.