38 Korean J Pain Vol. 24, No. 1, 2011 measured the position and angle of the herniated part from the center of the disc with MRI examination. According to this measured angle, the C-arm was tilted obliquely on the opposite side to the patient’s symptoms, and the needle entry point was marked with a surgical marker on the anterior neck relevant to the center of the disc to be treated. The paratracheal approach was used in the opposite site to the patient’s symptom. After the internal carotid artery was laterally displaced with the sur- geon’s index and middle fingers, the needle entry site was secured. Then, the needle was introduced in the needle en- try point and advanced till the anterolateral annulus fibrosus. A syringe filled with 5 ml of 2% lidocaine was connected to the needle, and the local anesthetic was ad- ministered from the disc to the skin while checking that blood was not aspirated with repeated suction and injection. Next, we used the paratracheal approach again. After the patient’s internal carotid artery was displaced laterally and the needle puncture site was secured, a 19 gauge 3 inch Introducer needle (ArthroCare Co., Sunnyvale, CA, USA) was introduced in the needle entry point and ad- vanced until it reached the annulus fibrosus. At this point, the AP and lateral views were gained to see if the in- troducer needle tip was in contact with the center of the disc height. Then, the oblique view was obtained to see that the introducer needle was directed toward the center of the intervertebral disc and to guide the estimated pro- gression route. The introducer needle entry angle at the anterolateral border of annulus fibrosus was then adjusted if needed. After the introducer needle was advanced slightly deeper, C-arm fluoroscope images were obtained again to see whether the introducer needle was placed in the center of the disc according to the AP and lateral views. The stylet of the introducer needle was withdrawn, and the PercTM DC Spine WandTM (ArthroCare co., Sunnyvale, CA, USA) was replaced and fastened clockwise to the needle hub. In the fastened state, the PercTM DC Spine WandTM and introducer needle were advanced slightly Fig. 1. Intraoperative fluoroscopic imaging. PercTM DC Spine WandTM placement adjacent to the lesion sites within the C5-6 intervertebral disc level during ablation. (A) Antero-posterior views. (B) Oblique views. (C) Lateral views.