[An angiographic study of spinal vascularization at the thoracic-lumbar level].

In this retrospective work based on a series of spinal angiograms performed in the Neuroradiology Department of the Salpêtrière Hospital, Paris, we studied the number of examinations that showed one or several anterior radiculospinal arteries at the thoracolumbar level, as well as their origin at different levels from T6 to L3. Analysis of the whole group of 552 patients showed some deviation from the previously published radio-anatomical papers. This was confirmed and illustrated more clearly by the analysis of a series of 174 cases selected among these 552 patients. This second series was particular in that it featured bilateral catheterization of every artery likely to give off a radiculospinal artery at all levels from T6 to L3, thus providing more reliable statistical data. We found that 48% of the patients had their thoracolumbar blood supply based on two anterior radiculospinal arteries the lowest of which was located at, or lower than, T12, and the second and higher one between T6 and T10. Only 45% of the studies showed a blood supply relying on a single anterior radiculospinal artery which most frequently had its origin at T9. In 7% of the cases the thoracolumbar spinal cord was supplied by 3 anterior radiculospinal arteries. Our results demonstrate the presence of at least two different patterns of spinal cord blood supply at the thoracolumbar level, with a variation in the origin of the anterior radiculospinal arteries. These recent findings may increase the reliability and improve the technique of spinal angiography, especially in difficult cases.