<prompt> After doing a graft repair of a thoraco-abdominal aneurysm, the patients developed weakness. Most propable cause for this:Decreased blood supply to the lower limbsThoraco splanchnic injuryDiscontinuation of aeria radicularis magnaLumbosacral nerve injury  <response>: Aeria Radicularis Magna: Aeria radicularis magna aery of Adamkiewicz is the main source of blood supply to the anterior spinal aery in the thoracolumbar segment of the spinal cord. It arises from either one of the lower posterior intercostal aeries T9-T11 or of the subcoastal aery T12, or less frequently of the upper lumbar aeries L1 and L2 Occlusion or interruption is one of the major reasons for spinal cord ischemia leading to paraparesisParaplegia during surgery for thoracoabdominal aneurysm. Ref: Sabiston 20th edition Pgno: 1788 