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Abstract The main arterial supply of the dorso-lumbar spinal cord is usually derived from a single anterior radiculo-medullary artery called the artery of Adamkiewicz and referred to as having a middle or low location. In some cases, the artery origin is higher, and a vessel which arises in the lower part of the region supplements the supply of the anterior spinal artery. In the literature, those arteries have been described as arising from L3 upwards, and have never been previously described angiographically, to our knowledge, below this level, although Suh and Alexander and Gililan have mentioned this eventuality. Of the 4,000 spinal cord angiographies performed in our institution, we report three cases in which the fourth lumbar artery flows into the anterior spinal artery of the conus medullaris. This anatomical variant may explain the sometimes devastating post-operative neurological complications from a spinal cord infarction on surgery of the lumbar spine or the abdominal aorta below L3.
Keywords Anterior spinal artery * Anterior radiculo-medullary artery * Artery of Adamkiewicz * Spinal cord * Spinal cord angiography * Spinal cord ischemia * Conus medullaris artery
Introduction
Anatomical knowledge of the spinal cord arterial blood supply is crucial for the therapeutic approach to spinal vascular malformations in interventional neuroradiology, as well as for selective screening of the anterior spinal artery in prevention of post-operative neurological complications following surgery on the upper lumbar spine or abdominal aorta. We report three exceptional cases, documented with spinal cord angiography, in which the fourth lumbar artery supplies the anterior spinal artery of the conus medullaris. The frequency of this anatomical variant, never previously described in the literature, is unknown but probably very low. Its existence calls for a description of these three observations because such an anatomical variant may explain the sometimes devastating post-operative neurological complications from a spinal cord infarction.
Case reports
Case 1
A 56-year-old European male patient without significant previous medical or surgical history developed a rapidly progressive paraplegia of unknown cause. MRI of the lumbar spine showed a central cord lesion of the conus medullaris extending up to the Tl2 vertebral body, giving low signal on Tl weighting and high signal on T2 weighting without intra- or peri-medullary contrast enhancement after gadolinium administration (Fig. Ia). There was...