Clinical markers in CSF for determining neurologic deficits after thoracoabdominal aortic aneurysm repairs.
BACKGROUND
Spinal cord ischemia is a major cause of morbidity and mortality after thoracoabdominal aortic aneurysm operations. The incidence of paraplegia is high even in experienced institutions.


METHODS
We investigated whether neurotransmitter excitotoxicity is associated with neurologic deficits after thoracoabdominal aortic aneurysm operations. We hypothesized that patients with spinal cord injury would manifest elevated levels of excitatory amino acids in their cerebrospinal fluid. Sixteen patients undergoing thoracoabdominal aortic aneurysm operations had cerebrospinal fluid drawn through lumbar spinal drains preoperatively, intraoperatively, and postoperatively. Excitatory amino acid levels (glutamate, aspartate, glycine) were measured using high-performance liquid chromatography. Excitatory amino acid levels were compared in patients who exhibited no neurologic deficits postoperatively (group I; n = 12) with patients who had clinically evident lower extremity and cerebral neurologic deficits (group II; n = 4).


RESULTS
Significant elevations in glutamate and aspartate levels from baseline (p < 0.05) were limited to group II. Excitatory amino acid levels in group II were significantly elevated (p < 0.05) compared with those observed in group I. Glutamate levels were especially increased during aortic cross-clamping and late reperfusion, whereas aspartate levels were increased only during late reperfusion.


CONCLUSIONS
These data suggest that neurotransmitter excitotoxicity plays a significant role in central nervous system injury.
Brock
M V
MV
Division of Cardiothoracic Surgery and the Kennedy Krieger Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA.
Redmond
J M
JM
Ishiwa
S
S
Johnston
M V
MV
Baumgartner
W A
WA
Laschinger
J C
JC
Williams
G M
GM
D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000601:surgery*; D002493:Central Nervous System Diseases / Q000134:cerebrospinal fluid / Q000209:etiology; D018846:Excitatory Amino Acids / Q000134:cerebrospinal fluid*; D005260:Female; D005998:Glycine / Q000134:cerebrospinal fluid; D006801:Humans; D008297:Male; D013119:Spinal Cord Injuries / Q000134:cerebrospinal fluid*
D018846:Excitatory Amino Acids; D005998:Glycine