Thoracic radicular vessels by simultaneous intra-arterial and intravenous injection of araldite.

Spinal dural arteriovenous fistulas (SDAVF) consist of a shunt between a radicular artery and a radicular vein, resulting in a progressive paraparesis. They are most prevalent in middle-aged men (male to female ratio 5 to 1). It is unknown why the shunt develops. It is possible that there are anatomical differences between men and women, which may account for the sex difference in prevalence. We performed a study with simultaneous arterial and venous araldite injection in 5 male and 5 female human cadavers using different colors. The mean age of the human cadavers was 78 years (range 70-91). The human cadavers were not known to have suffered from spinal disease. We did not find significant differences in thoracic vasculature between men and women. Two different types of radicular arteries could be identified: The first was the arterial feeder of the root ganglion or the dura mater, which is also called the distal radicular artery. The second was the tributary of the anterior spinal artery, which is also called the medullary artery. We found three arteriovenous anastomoses between the radicular artery and the corresponding vein, and three between the radicular artery and venous plexus. We found a total of six thoracic arteriovenous shunts in four cadavers but their role in the pathogenesis of SDAVF remains uncertain. No vascular anatomic differences between men and women were found.