A Novel Untethering and Duraplasty Technique for Postsurgical Tethered Spinal Cord

Abstract

Progressive post-traumatic postsurgical myelopathy (PPPM) is a known entity that can occur months to years after the initial insult. Symptomatic patients can become myelopathic and have rapid and progressive neurological decline. Surgical correction of PPPM usually involves intradural exploration and lysis of adhesions that carries the risk of further injury to the spinal cord. In this manuscript, we provide a report of a patient presenting more than 50 years after the initial resection of an intramedullary tumor. Additionally, we present and describe a novel surgical technique for managing this difficult problem and restoring normal CSF dynamics.

Keywords: duraplasty; intramedullary spinal cord tumor; progressive postsurgical myelopathy; spinal cord injury; tethered spinal cord.

Figure 1. Preoperative MRI of the cervical spine with mid-sagittal view (A) and selected axial T2-weighted images at C3/4 (B), C4/5 (C) and C5/6 (D), demonstrating dorsal tethering of the cervical spinal cord to the overlying dura from approximately C3 to C7. There is eccentricity of the tethering to the left side, as well as a large central syrinx with marked atrophy of the cord.

Figure 2. CT myelogram of the cervical spine with mid-sagittal view demonstrating a posterior laminectomy from C2 to C7 (A) and selected axial images at C3/C4 (B), and C4/C5 (C) with multiple areas of dorsal tethering of the spinal cord, as well as obstruction of CSF flow ventral to the cord, suggestive of an arachnoid cyst. Scatter is occurring due to numerous retained vascular clips from previous surgical interventions.

Figure 3. Intraoperative photograph of dural placode

* dural placode

Figure 4. (A) Intraoperative photograph of the “Billowing Duraplasty” being sutured in place. (B) The completed sutured duraplasty.

* represents allograft ** represents the underlying adherent placode Black dot shows completed sutured duraplasty

Figure 5. Postoperative MRI of the cervical spine with mid-sagittal (A) and selected axial T2-weighted images at C3/4 (B), C4/5 (C) and C5/6 (D) demonstrating a more ventral position of the cord compared to the preoperative imaging studies, and restoration of space and CSF fluid volume within the dorsal cistern. There is increased space between the spinal cord and the reconstructed dura, which has been facilitated by the “billowing duraplasty.” Note the presence of the retained, adherent dural placode on the dorsal aspect of the spinal cord, represented by the region of low signal on the T2-weighted images, best seen on the mid-sagittal slice.