Prevention of recurrent tethered spinal cord.

One of the most problematic technical considerations in surgery for the release of tethered spinal cord is how to prevent recurrent tethering. Recurrent tethering is common because the spinal canal in the baby is shallow and, therefore, postoperatively, the neural contents are in direct contact with the posterior dura. The only way to prevent a recurrent tethered cord is to be certain that the neural elements remain free within circumferentially patent cerebrospinal fluid. We hereby describe a method where a curved 1.5 mm oval piece of Medpor is used to create a posterior space for the neural elements. The spinal canal is expanded posteriorly, therefore, creating an abnormally wide canal to accommodate the neural elements within subarachnoid space. This methodology was used in 18 neonate patients, and in late tethering cases after myelomeningocele. Technical and theoretical considerations are discussed.