Third, magnetic resonance imaging (MRI) revealed soft thoracic disc herniation. And finally discography confirmed painful disc before the surgical procedure. Patients with Paclitaxel calcified discs or hard disc herniations were not treated with this procedure. 2.2. Tools During the surgical procedure, a burr, a bone shaver, and the Holmium-YAG laser were used to undercut the facet and rib head for foraminotomy. Discectomy was achieved by using a grasper, radiofrequency, and the Holmium-YAG laser. The surgical procedures were performed with the assistance of an 8mm (outer diameter) Wolf endoscope (Richard Wolf Medical Instruments Corporation, Vernon Hills, IL, USA). 2.3. Surgical Technique The procedures were performed under local anesthesia with the patient in a prone position on a radiolucent table.

The target disc was identified under fluoroscopic guidance (Figure 1(a)), and the entry point between the rib head and the facet (on oblique view) was marked on the skin (Figure 1(b)). Discography was performed to confirm the target disc and to help identify the location of the herniation. The 18 G needle inserted to perform discography was parallel to the upper endplate of the lower vertebral body (Figure 2). The tip of the needle reached posterior disc margin (on the lateral view) and was situated between midline and medial pedicle line (on the AP view). The surgical region was anesthetized with a combination of 0.5% lidocaine and epinephrine. Figure 1 The target disc was identified under fluoroscopic guidance (a), and the entry point between the rib head and the facet was marked on the skin (b).

Figure 2 Discography was performed to confirm the target disc and to help identify the location of the herniation; the needle was parallel to the upper endplate of the lower vertebral body. After discography, a guiding wire was inserted through the needle, and a 10mm skin incision was subsequently made. The needle was removed, and a sequential dilator was then inserted over the wire towards the posterolateral margin of the facet (Figure 3(a)). Once the tip of the dilator reached the surface of the annulus, the guiding wire was removed and the dilator was further inserted into the target foramen. A working cannula was then guided to the extraforaminal region over the dilator (Figure 3(b)). At this juncture, the dilator was removed and the endoscope was placed to assist with visualization.

Figure 3 A sequential dilator was then inserted over the wire towards the posterolateral margin of the facet (a). A working cannula was Entinostat guided to the extraforaminal region over the dilator (b). To perform foraminotomy, we first titled the cannula to expose the foraminal epidural space. We then used an Ellman radiofrequency probe (Ellman International, New York, USA) and a shaver to expose the facet medially and rib head laterally (Figure 4).