Regional spinal cord blood flow measurements (r.S.C.B.F.) in spinal cord acute compression caused by an epidural balloon.

Our study was carried out in 34 rabbits which were divided into three groups (A, B, C). In group A (10 animals), a mid-laminectomy of the first lumbar (L1) vertebra was performed and the circulation in the exposed spinal cord segment was examined using both procedures, the videomicroscopy as well as the r.S.C.B.F. measurement (by intraarterial-5th radicular injection of 2.5 mic133 Xe). In group B (10 rabbits) after the performance of L1 vertebra mid-laminectomy, a teflon catheter was introduced through T11-T12 (thoracic) intervertebral foramina and 0.5 ml of metrizamide sodium was injected through the balloon producing, thus, a 36 +/- 1% stenosis in the diameter of the corresponding spinal canal level. Using the procedures described above as well as light microscopy it was shown that, during the period of the 4 hours the experiment lasted, the circulatory disturbances of spinal cord were still reversible. On the contrary, in group C (14 rabbits) where 0.8 ml of metriz amide sodium was injected through the balloon catheter producing, thus, a 52 +/- 1% stenosis in the corresponding spinal canal level, the spinal cord disturbances proved irreversible after the 4-hour period of the experiment's duration.