General Spine

Amish, H, Doshi, MD
Amit, Aggarwal, MD, Non ASSR Member
Puneet, S, Pawha, MD, Non ASSR Member
Chun, Chen, MD, Non ASSR Member
Michael, Sacher, MD, Non ASSR Member
Girish, Fatterpekar, MD, Non ASSR Member

Excerpta

We present a case of a 49-year-old male with a 2 year history of low back pain, radiculopathy, and lower extremity numbness. The patient had undergone conservative management with analgesics, steroids and physical therapy without significant improvement. He was then referred for surgical management.

The patient underwent multiple MRI examinations of the lumbar spine spanning several months, including 6/10/09, 9/1/09 and 9/18/09. Initial noncontrast MRI examinations of the lumbar spine demonstrated degenerative changes of the spine, which were most prominent at the L4/5 and L5/S1 disk spaces. The patient returned for a contrast-enhanced MRI of the lumbar spine on 9/18/09 to evaluate a mild central T2 hyperintensity within the distal cord and conus seen on the examination performed on 9/1/09. The post contrast MRI demonstrated a mass within the ventral epidural space at the L5 vertebral level with areas of T2 hypointensity and prominent homogenous enhancement. This finding developed between the MRI examinations of the lumbar spine between 9/1/09 and 9/18/09 (over the course of approximately 17 days). Given the relatively rapid appearance and prominent enhancement of this abnormality, the possibility of a prominent epidural venous plexus was proposed. Neuroradiology advised neurosurgery to defer biopsy given the potentially vascular nature of this structure.

The patient underwent surgical intervention with discectomy, facetectomy and foraminotomy at the L4/5 and L5/S1 levels. During the procedure the neurosurgeon performed a digital palpation along the L5 ventral epidural space and described a soft pliable structure in the region of interest, consistent with a vascular structure.

Discussion:

Enlargement of the epidural venous plexus has been implicated in cases of radiculopathy and myelopathy related to local mass effect and can be clinically indistinguishable from a herniated disc. In addition, a prominent epidural venous plexus has uncommonly been reported in the literature as mimicking an epidural mass.

Engorgement of the epidural venous plexus can occur in multiple settings, which include patients with inferior vena cava/iliac vein occlusion, intracranial hypotension, Marfan syndrome and associated vascular abnormalities such as arteriovenous malformations, fistulas, and varicose veins. Venous occlusion can result in lumbar epidural engorgement secondary to venous reflux into the valveless epidural plexus. This can be manifested on MRI as a prominent epidural venous plexus or epidural venous varices.

In the case presented, the patient had no known predisposing conditions. In addition, he underwent several MRI examinations that demonstrated degenerative disk disease without evidence of epidural prominence. The presumed engorged epidural venous plexus seen on the immediate pre-operative MRI was considered an incidental finding, rather than the primary etiology of the patientâ