Identification of the critical spinal arteries with F wave-polysynaptic response complex monitoring: an experimental study.
OBJECTIVE
The main cause of paraplegia after surgery for descending thoracic aortic aneurysms and thoracoabdominal aortic aneurysms is spinal cord ischemia caused by ligation of the critical spinal arteries that are associated with the great radicular artery (GRA). In this experimental study, we attempted to identify the critical spinal arteries with F wave-polysynaptic response complex (FPC) monitoring. The FPC, which we are using as a monitor of spinal cord ischemia, is myogenic potentials evoked by the tibial nerve stimulation through the anterior horn cells.


METHODS
In 18 rabbits, infrarenal lumbar arteries were clamped until there was an FPC amplitude reduction (FPCAR) of at least 60%. The rabbits were classified according to the number of arteries clamped to produce the FPCAR (group A, 1 artery; group B, 2 arteries; group C, 3 arteries). Selective angiography of each lumbar artery was performed in all rabbits.


RESULTS
An FPCAR was observed in all 18 rabbits. In all nine rabbits in group A, the FPCAR was caused by the clamping of one particular lumbar artery. The GRA was shown by means of selective angiography to originate directly from this lumbar artery. In the nine rabbits in groups B and C, 11 FPCARs were observed. Of these, nine FPCARs in nine rabbits were caused by the clamping of lumbar arteries that included the vessel from which the GRA originated.


CONCLUSIONS
Temporary clamping of lumbar arteries with FPC monitoring can be used as a means of detecting the critical spinal arteries from which the GRA originates.
Iyori
K
K
Second Department of Surgery, Yamanashi Medical University, Japan. iyori777@ea.mbn.or.jp
Kamiya
K
K
Suzuki
O
O
Kojima
A
A
Kubota
K
K
Ishimoto
T
T
Kobayashi
M
M
Shindo
S
S
Tada
Y
Y
D000200:Action Potentials; D000792:Angiography; D000818:Animals; D001158:Arteries / Q000502:physiology; D004558:Electric Stimulation; D004576:Electromyography; D004594:Electrophysiology; D008297:Male; D011817:Rabbits; D013131:Spine / Q000098:blood supply*; D009435:Synaptic Transmission / Q000502:physiology*