Fluoroscopy-Guided Transforaminal versus Caudal Epidural Steroid Injection for Chronic Pain After Spinal Surgery: A Retrospective Mid-Term Comparative Study

INTRODUCTION: This study is to compare advantages, safety and mid-term effects of fluoroscopy (FL)-guided transforaminal (TF) to caudal (CA) epidural steroid injection (ESI) for chronic pain after spinal surgery (CPSS) by assessing pain relief and improvement of functionality. METHODS: Patients with radicular pain in CPSS who received FL-guided CA (n = 21) or TF (n = 28) ESI were included in this retrospective study. Complication frequencies, adverse events, treatment effects, and functional improvements for each procedure were compared at 1, 3, and 6 months following the last injection. RESULTS: Both the Oswestry Disability Index (ODI) and verbal numeric pain scale scores (VNS) demonstrated improvement in both groups at all 1, 3, and 6 months following the last injection, without meaningful difference between groups (p < 0.05). Moreover, no meaningful difference was present between groups in terms of treatment success rate at every time point. The amount of time used for the injection procedure was shorter in CA group than in TF group (410.32 ± 25.73 seconds vs 640.65 ± 18.03 seconds, p < 0.05). Within 2 weeks of the injection treatment, the patient satisfactory scores were evaluated, with excellent being rated 85.7% (n = 18) among CA-ESI patients and 55.7% (n = 16) among TF-ESI patients (p < 0.05). Logistic regression analysis revealed that variables such as method of injection (CA or TF approach), sex, use of analgesics, pain duration, number of injections, and age were not significant variables for successful treatment results. There were no adverse complications after the procedure in both groups. CONCLUSION: The outcomes of FL-guided CA-ESI and TF-ESI for CPSS are similar in terms of pain reduction and functional improvements. CA-ESI is associated with lesser procedure time. In addition, compared with the TF-ESI, the patient experiences less discomfort during the injection, and the satisfaction with the injection treatment is confirmed to be better. Accordingly, both methods are effective; however, in the CA approach, patient satisfaction is higher and the procedure time is shorter.