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Spinal dural arteriovenous fistula associated with L-4 isthmic spondylolisthesis.

The authors describe a case of a 79-year-old man with a lumbar spinal dural arteriovenous fistula (DAVF) and isthmic spondylolisthesis at the same level. The patient's thoracic spine MRI study demonstrated swelling and increased T2 signal in the spinal cord and regional dilated perimedullary vessels. Lumbar spine MRI showed L-4 isthmic spondylolisthesis with severe bilateral L4-5 foraminal stenoses. Spinal angiography revealed a fistulous connection at the left L-4 nerve root sleeve between perimedullary veins and a dural branch of the L-4 radicular artery. Based on previous reports about secondary spinal DAVFs, the abnormal vascular communication likely developed secondary to the microtrauma and inflammation on the left L-4 nerve root sleeve, which was attributable to the isthmic spondylolisthesis. The authors performed disconnection of the arteriovenous shunt as well as an L4-5 decompression and posterior instrumented fusion with pedicle screws. The patient's postoperative course was uneventful, and he improved neurologically. It is important to bear in mind that a spinal DAVF may develop as a consequence of any sort of trauma or inflammation involving nerve roots. One should consider the concomitant treatment of both the spinal DAVF and the underlying pathology that may have given rise to the spinal DAVF.