Of the many potential causes of nerve compression that lead to radiculopathy, vascular etiologies remain among the most infrequent, with an estimated prevalence of only five to ten per million cases of radiculopathy. In this case report, we outline the clinical presentation, imaging, intraoperative findings, and pathologic findings for a fifty-four-year old patient with an intradural, extramedullary form of a spinal dural arteriovenous fistula at the L1-L2 level who presented only with axial back pain and radiculopathy. The radiologist and surgeon initially diagnosed the patient with a herniated nucleus pulposus. However, the intraoperative findings and angiogram were suggestive of an arteriovenous fistula. Methods to identify this rare entity are described for the orthopaedic spine community.
The potential for a missed diagnosis is particularly important as many partial discectomy procedures are performed at small surgical centers with limited blood products available and no vascular surgeon on staff. For patients with preoperative magnetic resonance imaging (MRI) that is suggestive of vascular malformations (T2 hyperintensity in the lower spinal cord and conus medullaris), we recommend that MR angiography be performed as a secondary diagnostic evaluation. MR angiography has a 95% positive predictive value for specifically diagnosing an arteriovenous fistula.
1Department of Orthopaedic Surgery, Thomas Jefferson University, 1025 Walnut Street, Room 516 College, Philadelphia, PA 19107. E-mail address for K. Verma: firstname.lastname@example.org
2Division of Neurovascular Surgery and Endovascular Neurosurgery, Thomas Jefferson University Hospital, 925 Chestnut Street, Philadelphia, PA 19107
3Orthopedic Spine Surgery, The Rothman Institute at Thomas Jefferson University Hospital, 925 Chestnut Street, 5th Floor, Philadelphia, PA 19107