Identification and selective perfusion of the spinal cord-feeding arteries by intrathecal pO2 monitoring for spinal cord protection.

OBJECTIVES

to study whether spinal cord-feeding arteries could be identified by the changes in the intrathecal pO2 (I-pO2), and to examine whether selective perfusion of feeding arteries identified by this method could protect the spinal cord against ischaemia.

DESIGN

controlled animal experiments.

MATERIALS AND METHODS

in experiment 1, using 16 mongrel dogs, 18 segmental arteries were cannulated through which oxygenated saline was injected and the I-pO2 change was observed. When the I-pO2 increase was more than 0.5 mmHg, the artery was considered to be a spinal cord-feeding artery. In experiment 2, involving 10 dogs, the segmental arteries identified as spinal cord-feeding arteries were perfused with arterial blood and the recovery of I-pO2 and evoked spinal potentials (ESP) was examined.

RESULTS

of 208 segmental arteries examined, 176 (84.6%) arteries were correctly judged and 32 (15.4%) were not. It was observed that the I-pO2 recovered from 13.9 to 30.5 mmHg and the ESP recovered from 20.9% and 8.2% to 66.5% and 44.7% of each control for the first negative (N1) and second negative (N2) components, respectively.

CONCLUSION

spinal cord-feeding arteries were successfully identified using the I-pO2 monitoring method. Perfusion of these arteries with arterial blood improved the I-pO2 and ESP, which were significantly depressed by ischaemia.