Caudal Epidural Injection with a Guidewire-Reinforced Epidural Catheter in Patients with Herniated Nucleosus Pulpose

Ko, Justin Sangwook; Lee, Seok Jin; Hwang, Hee Youn; Sim, Woo Seok; Choi, Soo Joo; Kim, Jie Ae; Kim, Chung Su; Hahm, Tae Soo; Kim, Gaab Soo; Cho, Hyun Sung; Kim, Tae Hyeong

Abstract

BACKGROUND
The epidural injection technique is a commonly used intervention in the management of chronic spinal pain, which has the advantage of delivering various drugs, such as local anesthetics or steroids, in higher concentrations to the inflamed nerve root. A guidewire-reinforced epidural catheter was introduced through a Tuohy needle during the caudal epidural procedure, with a catheter threaded into the affected nerve roots and the spread-pattern of contrast agents observed under fluoroscopy. METHODS: Sixty-seven patients with low back pain, who showed evidence of a herniated nucleus pulposus on magnetic resonance imaging, were included. All patients received fluoroscopically guided caudal epidural injections, with the guidewire-reinforced epidural catheter introduced through a Tuohy needle and threaded either to the right or left side toward the target nerve roots. After confirming the catheter tip position at the affected nerve root, 2 ml increments of contrast agents (up to 6 ml) were injected, and their corresponding AP fluoroscopic views were obtained. Three radiologists reviewed all the radiographic findings and measured the proportion of the area of contrast spread at the side of target nerve roots. RESULTS: Greater proportion of the area of contrast spread was observed at the side of the target nerve roots (P < 0.0001). At each level of contrast injection (2- , 4- and 6 ml), more than 70% of the spread of contrast dye was observed at the side of the target nerve roots in 85%, 70%, and 55% of cases, respectively. CONCLUSIONS: The combination of a caudal epidural injection and use of a guidewire-reinforced epidural catheter significantly enhances the target specificity, as revealed by the selective spread of contrast dye at the side of target nerves.