Experimental study on the circulatory dynamics of the spinal cord by serial fluorescein angiography

The circulatory dynamics on the dorsal surface of the spinal cord were observed by serial fluorescein angiography . Fluorescein dye appeared in the posterior spinal artery and pial arterial plexus, although the direction of blood flow might be opposite and the time taken for fluorescein dye to enter the arteries was different for each. Fluorescein dye appeared in the veins after various periods, and the directions of flow of the dye were also variable and complicated. Laminar flow often was observed in veins of less than 200 microns in diameter. The regional circulation time was calculated to be 2.1 +/- 0.4 seconds. There was no extravasation.