Tethered cord due to caudal lipomeningocele associated with a lumbar dural arteriovenous fistula.

A 29-year-old man presented with progressive paraparesis associated with sensory impairment in both lower limbs for the past 2 years. He was experiencing the sensation of incomplete urinary evacuation. The patient had undergone an earlier operation for a lumbar lipomeningocele at birth. Magnetic resonance images of the lumbosacral spine showed a low-lying conus medullaris adherent to a caudal lipoma. There was a leash of abnormal vascular channels in the adjacent subarachnoid space. The patient underwent spinal angiography that revealed a dural arteriovenous fistula (AVF) principally fed by the left fourth lumbar (L-4) radicular branch. At surgery the cord was detethered by disconnection of the sacral lipoma. The dural fistula was obliterated by occlusion of the L-4 radicular feeder close to the nidus of the fistula. Postoperatively, the patient experienced an immediate relief of sensation of tightness in both lower limbs. There was a gradual improvement of power and sensation at the 6-month follow-up examination. According to the authors' literature search, the present case is a unique report of a rare association of spinal cord tethering due to a caudal lipoma associated with a lumbar dural AVF. The present report discusses the etiopathology, presentation, and management of this case.