Thoracic transdural spinal cord herniation at a level caudal to prior discectomy

To outline a scenario of acquired transdural spinal cord herniation not previously described. The authors report their experience with a patient found to harbor a thoracic transdural spinal cord herniation at the disk space immediately caudal to a prior discectomy. Documentation of the radiographic progression of this patient's spinal cord herniation is presented, spanning the course of 13 years. The patient underwent intradural repair of his dural defect via a lateral extracavitary approach. The herniated spinal cord was successfully reduced. The patient had modest improvement in his symptoms at 2-year follow-up. To the best of the authors' knowledge, this case represents the first reported case documenting this anomaly at a level adjacent to that of a previous surgery within the thoracic spine.