Catheter-Based Transepidural Approach to Cervical and Thoracic Posterior and Perineural Epidural Spaces: A Cadaveric Feasibility Study.

BACKGROUND AND OBJECTIVES Approaching the cervical and high thoracic level epidural space through transepidural route from lumbar region represents a method to lower the occurrence of complications associated with direct approach. The authors performed a cadaveric pilot project to determine the feasibility of various catheter-based manipulation and cephalad advancement using the transepidural route. STUDY DESIGN AND METHODS Two cadavers were used to determine the following: 1. Ability to place a guide sheath over a guidewire using a percutaneous approach within the posterior lumbar epidural space; 2. The highest vertebral level catheter can be advanced within the posterior epidural space; 3. Ability to cross midline within the posterior epidural space; and 4. Ability to catheterize the perineural epidural sheaths of the nerve roots exiting at cervical and thoracic vertebral levels. RESULTS We were able to advance the catheters up to the level of cervical vertebral level of C2 within the posterior epidural space under fluoroscopic guidance from a sheath inserted via oblique parasagittal approach at the lumbar L4-L5 intervertebral space. We were able to cross midline within the posterior epidural space and catheterize multiple perineural epidural sheaths of the nerve roots exiting at cervical vertebral level of C2, C3, and C4 on ipsilateral or contralateral sides. We also catheterized multiple epidural sheaths that surround the nerve roots exiting at the thoracic vertebral level on ipsilateral or contralateral sides. CONCLUSIONS We were able to advance a catheter or microcatheter up to the cervical vertebral level within the posterior epidural space and catheterize the perineural epidural sheath of the nerve root exiting at cervical and thoracic vertebral levels. Such observations support further exploration of percutaneous catheter based transepidural approach to cervical and thoracic dorsal epidural spaces for therapeutic interventions.