Introduction: Tethered cord syndrome (TCS) is defined by a set of neurological, orthopedic, and urological signs and symptoms resulting from abnormal stretching of the distal spinal cord. This condition is caused by tissue attachments that fix the spinal cord to the spinal column. Open surgery to untether the spinal cord is currently the gold standard of treatment. However, minimally invasive endoscopic spinal surgery should be explored for its potential benefits in TCS. Here, we simulated an endoscopic untethering of the spinal cord to safely demonstrate the plausibility of this procedure.

Methods: A male cadaver was placed in a prone position on a flat surface. Dilators were inserted through two 8 cm midline incisions at vertebral levels T12-L1 and L4-L5. Laminectomy was performed at both locations to expose the contents of the spinal canal. A cannula was introduced into the subarachnoid space at the superior (T12-L1) opening to provide a steady infusion of saline to mimic CSF, simulating the normal conditions under which endoscopy is performed. In the inferior (L4-L5) opening, a 5 mm dural incision was made using endoscopic scissors and the fatty filum terminale was identified in the dorsal midline and sectioned. Endoscopic visualization was maintained throughout the duration of the procedure. Subsequently, the dura surrounding the L4-L5 spinal segment was completely removed to allow for direct visualization of the cut filum.

Results: We demonstrated successful sectioning of the filum terminale using spinal endoscopy.

Conclusions: Although open surgical management of TCS has resulted in good postoperative outcomes, endoscopic untethering provides many additional practical benefits. These include reductions in soft tissue injury, blood loss, postoperative pain, scarring, and recovery duration. Moreover, endoscopic untethering may decrease the incidence of retethering due to less scarring, which has been shown to be a contributing factor. Lastly, we have demonstrated the usefulness of cadavers as an educational tool.

Patient Care: Minimally invasive endoscopic untethering surgery will reduce tissue injury, blood loss, postoperative pain, scarring, and recovery duration, and thus will improve overall patient care in the treatment of TCS. Our cadaver simulation builds upon a few examples of endoscopic untethering in the literature, which will stimulate further discussion on and future application of this relatively new technique.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the pathophysiology of tethered cord syndrome, 2) Understand the differences between open surgical untethering and endoscopic untethering, and 3) Discuss potential challenges to endoscopic untethering and their possible solutions.

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