The Catheter Tip Position and Effects of Percutaneous Epidural Neuroplasty in Patients with Lumbar Disc Disease During 6-Months of Follow-up

Background: Percutaneous epidural neuroplasty (PEN) is a minimally invasive intervention designed to treat neck, back, and low back pain. The efficacy of lumbar PEN has been relatively well investigated, but clinical effectiveness according to catheter position has not yet been established. Objective: The purpose of this study was to compare clinical outcomes between the ventral and dorsal positions of the catheter tip during lumbar PEN procedures using a retrospective review series. Methods: A total of 303 patients with back pain from single-level lumbar disc disease with and without radiculopathy were included in this study. In all patients, an attempt was made to place the catheter tip in the ventral position to maximize theoretical clinical improvement; however, several catheters failed to reach the desired position. Patients were assigned to 2 groups after lumbar PEN procedures were completed: those with catheters in the ventral position (Ventral group) and those with catheters in the dorsal position (Dorsal group). Clinical outcomes were assessed according to the Visual Analog Scale (VAS) score for back pain and leg pain at 0, 1, 3, and 6 months after treatment. Results: The only demographic difference observed between the 2 groups (Ventral and Dorsal groups) was an elongated symptom duration in the Dorsal group compared to the Ventral group (16.1 vs. 9.4 months, P = 0.013). The VAS (back) scores during the follow-up period (1, 3, and 6 months) were similar between the 2 groups. In one area of the VAS scoring (leg), the Ventral group showed a similar effect at postoperative one month compared to the Dorsal group, but significantly improved at postoperative 3 and 6 months (1.3 and 0.9 in ventral group, and 1.9 and 1.4 in dorsal group, respectively; P = 0.002 and 0.010). Odom's criteria were also significantly improved over 6 months in the Ventral group compared to the Dorsal group. Limitations: This study was a retrospective analysis with a relatively short follow-up duration was not a randomized, controlled study. Therefore, the clinical effects of the catheter position could be confounded by other variables. Conclusion: In this short-term follow-up study, the effects of lumbar PEN on VAS scores were different according to the position of the catheter tip in patients with single-level lumbar disc herniation. Better outcomes in the Ventral group may have been achieved by more localized treatment with a selective block in the epidural space closer to the dorsal root ganglion and ventral aspect of the nerve root.