Clinical Outcomes of Epidural Catheter Therapy as A Spinal Intervention: A Retrospective Statistical Study

Introduction

Chronic spinal pain is one of the most prevalent chronic conditions worldwide and constitutes a major source of disability, reduced quality of life, and economic burden. Disc herniation and degenerative spinal disorders commonly lead to pain in the spine and neuroforaminal stenosis and recessal stenosis due to mechanical compression and inflammatory irritation of neural structures. Multiple anatomical components have been identified as potential pain generators, including intervertebral discs, nerve roots, facet joints, sacroiliac joints, ligaments, epidural tissues, and paraspinal musculature. However, a subset of patients fails to achieve sustained symptom relief despite optimized conservative and surgical therapy. Epidural catheter was developed in the late 1980s by Dr. Gabor B. Racz at the Texas Tech University Health Sciences Center. This technique has since been recognized as a pioneering advancement in the field of interventional pain management. Initially, the procedure involved the injection of normal saline alone through the ECT to achieve mechanical lysis of adhesions. A minimally invasive interventional technique aims to mechanically break up epidural adhesions that may trap nerve roots or impede drug delivery. Professor. Dr. Arous at this center developed this technique to include the administration of saline solution, enzyme agents such as hyaluronidase, and low doses of corticosteroids via catheter to enhance therapeutic efficacy and minimize side effects. These clinical evidences aim to support logical and systematic framework for the application of epidural interventions in the treatment of spinal pain. These recommendations are based on the best available evidence regarding the efficacy and safety of epidural interventions and related interventional procedures for the treatment of spinal pain, including pain caused by herniated discs, spinal stenosis, and post-operative pain syndromes. We hypothesized that percutaneous ECT would result in significant and sustained pain reduction and functional improvement in patients with disc herniation, intervertebral disc protrusion, nerve root compression, spinal canal stenosis, and postoperative pain syndrome with a low rate of complications and reduced need for surgical intervention.

Review of Evidence

Observational and controlled studies have demonstrated clinically meaningful pain relief in a substantial proportion of patients undergoing percutaneous epidural adhesiolysis, with reported improvement rates approaching 80%. We hypothesized that percutaneous ECT would result in significant and sustained pain reduction and functional improvement in patients with disc herniation, intervertebral disc protrusion, nerve root compression, spinal canal stenosis, with a low rate of complications and reduced need for surgical intervention.

Methods

Study Design

This retrospective observational study was conducted at our center.

Data analyses contain retrospective review and statistics.

Study Population

Patients mean age was 54 years with MRI-confirmed lumbar, thoracic, or cervical disc herniation, neuroforaminal stenosis and recessal stenosis, nerve root compression or spinal canal stenosis were included. Patients with progressive neurological deficits or cauda equina syndrome were excluded. The present statistical analysis was conducted using random sampling of patients treated over the last four years, in accordance with accepted standards for observational clinical research.

Inclusion Criteria

Adult patients were eligible for inclusion if they met the following criteria: radiologically confirmed disc herniation, disc protrusion, nerve root compression, spinal canal stenosis, epidural adhesion formation, or failed back surgery syndrome; presence of persistent radicular and/or axial spinal pain refractory to conservative therapy; and clinical stability without progressive neurological deterioration.

Exclusion Criteria

Patients were excluded if they had known coagulation disorders (including hemophilia or other bleeding diatheses), active local or systemic infection, inflammatory or autoimmune disease affecting the spine, significant vascular pathology, and pregnancy, known hypersensitivity to any component of the treatment protocol, progressive neurological deficits, or cauda equina syndrome. Epidural catheterization was deliberately avoided in patients with increased risk of bleeding or infection to ensure procedural safety.

Diagnoses

This procedure was applied to patients diagnosed with a range of spinal pathologies, including intervertebral disc protrusion, nerve root compression, spinal canal stenosis, postoperative pain syndrome (failed back surgery syndrome), lumbar disc herniation, and epidural adhesion formation.

Treatment Protocol

At our center, the protocol includes the administration of normal saline combined with hyaluronidase and very low-dose corticosteroids (17), in addition to Osmofundin 15% N (Mannitol) and Ropivacaine 2mg/ml for analgesia. This multimodal approach aims to reduction of pressure, edema, and inflammation on nerve roots, in addition to the fact that enzymes aid in making the herniated nucleus pulposus smaller and softer over time. The procedure is performed under CT guidance during the first session to ensure highly accurate access to the targeted anatomical region. Subsequently, over the following four days, the same medications are administered twice daily with a three-hour interval between injections. Although the foundational protocol was designed to mechanically break down adhesions using catheter-directed fluid and medication, in our practice the procedure has been further refined by the addition of agents such as hyaluronidase, very lowdose corticosteroids, normal saline, and adjunctive analgesics prior to consideration of surgical intervention in patients with pain related to disc herniation, spinal stenosis, or nerve root compression. Observational and controlled studies have demonstrated clinically meaningful pain relief in a substantial proportion of patients undergoing percutaneous epidural adhesiolysis, with reported improvement rates approaching 80% in selected cohorts. In addition, patients with secondary conditions resulting from spinal stenosis, including chronic radicular pain and functional impairment, were also included in the treatment protocol.

Post-Treatment Rehabilitation

Following completion of ECT, all patients were advised to participate in physical therapy, swimming, and regular exercise as part of a comprehensive rehabilitation program. Following ECT, patients who demonstrated insufficient clinical improvement and declined surgical intervention received additional supportive pain management in conjunction with structured physical therapy and supervised exercise programs. In patients who demonstrated clinical improvement following ECT, the supportive pharmacological treatment plan was implemented for a duration ranging from one week to one month, depending on individual pain severity and clinical response. Analgesic therapy in this subgroup was administered in a stepwise manner based on the principles of the World Health Organization (WHO) analgesic ladder. Patients with mild residual pain were treated with nonopioid analgesics (step 1). In cases of moderate pain, medium potency opioids such as Tilidine Hydrochloride were prescribed (step 2). Patients with severe pain received high potency opioids, including oxycodone (step 3). In refractory or persistent cases, advanced pain management strategies were employed, including transdermal opioid patches and, in selected patients, implantation of a subcutaneous pain pump for continuous analgesic delivery. In addition, muscle relaxants were prescribed in selected patients presenting with paraspinal muscle spasm in order to reduce muscle-related pain, improve mobility, and support functional rehabilitation. This selective multimodal post-interventional approach aimed to optimize pain control, facilitate functional recovery, and support rehabilitation in patients who did not achieve sufficient symptom relief following ECT alone.

Intervention Description

Epidural Catheter involves the placement of a catheter into the epidural space with the active aim of relieving nerve root compression and improving nerve root mobility, particularly in cases involving extruded components of the intervertebral disc. Catheter insertion was performed using either the sacral canal or the interlaminar to reach the targeted anatomical region. The procedure lasted approximately 10–20 minutes and was performed under light sedation with CT guidance [1]. The catheter remained in the epidural space for a duration of five days. This is followed by a standardized injection protocol designed to mechanically decompress the affected structures, expand the involved epidural tissue layers, and facilitate optimized targeted drug delivery. Following medication injection, the catheter was secured and covered with a sterile dressing to maintain aseptic conditions. This

technique has been extensively described in the literature and is commonly employed in patients with chronic spinal pain who are refractory to conventional conservative treatment modalities (Figures 1,2).

Figure 2

Outcome Measures

Primary outcomes included pain reduction assessed by VAS and ODI. Secondary outcomes included the need for subsequent surgical intervention. Follow-up was conducted using standardized outcome assessment principles in line with WHO recommendations for the evaluation of acute and chronic pain and clinical outcome reporting. Patients were assessed at predefined time points, including baseline (pre-treatment), 1 week, 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and during long-term follow-up when available Pain intensity was evaluated using the VAS, which is an internationally validated instrument recommended for pain-related outcome measurement. Clinical improvement, adverse events, and the need for additional interventions were systematically documented at each follow-up visit. This structured follow-up protocol allowed consistent monitoring of treatment effectiveness, functional recovery, and safety over time. Follow-up evaluation was additionally performed using Magnetic Resonance Imaging (MRI).

Statistical Analysis

Paired-samples t-tests were used to compare pre- and post-treatment outcomes for pain intensity VAS and functional disability ODI. Effect sizes were calculated using Cohen’s dz, which is recommended for within-subject (paired) designs. Ninety-five percent confidence intervals (95% CI) were computed to assess the precision of effect size estimates. Statistical significance was set at p-value < 0.05 was considered statistically significant. All analyses were performed using SPSS (31.1.0(49)).

Ethical Approval

This descriptive research is anonymous and retrospective in nature. General ethical approval is granted by German Medical Association to these studies as per professional law of physician.

Results

A total of 200 patients were included in the analysis. The mean age was 54 years, and 73% were female. The treated spinal levels included cervical (C5-C6, C6-C7), thoracic (T7-T8), and lumbar (L3-L4, L4-L5, L5-S1) segments, with L5-S1 being the most frequently treated level.

The mean baseline VAS score was 8.29 ± 1.24, which decreased to 2.62 ± 1.63 following treatment. Paired-samples analysis demonstrated a significant reduction in pain intensity, with a mean difference of 5.67 ± 1.58 (95% CI: 5.45–5.89; t(199) = 50.88, p < 0.001). A moderate correlation between pre- and post-treatment VAS scores was observed (r = 0.426, p < 0.001), indicating consistent withinsubject improvement. The magnitude of treatment effect was large, with Cohen’s d = 3.60 (95% CI: 3.22–3.98) and Hedges’ g = 3.58 (95% CI: 3.21–3.96). Similarly, ODI scores improved substantially from 73.89 ± 12.19 at baseline to 20.10 ± 12.44 post-treatment. The mean difference was 53.79 ± 13.25 (95% CI: 51.94–55.64; t(199) = 57.41, p < 0.001). A comparable moderate correlation was observed between pre- and post-treatment ODI scores (r = 0.421, p < 0.001). The effect size for ODI improvement was also extremely large, with Cohen’s d = 4.06 (95% CI: 3.64–4.48) and Hedges’ g = 4.04 (95% CI: 3.62–4.46), supporting the robustness of the observed functional The relative magnitude of improvement was considerable, with a mean percentage improvement of 68.9% for VAS and 73.2% for ODI. Clinically meaningful response was achieved in the vast majority of patients: 191 patients (95.5%) met the responder criterion of ≥50% improvement in both pain and disability outcomes. Furthermore, 194 patients (97.0%) demonstrated at least some reduction in pain intensity, while 6 patients (3.0%) showed no change and none experienced worsening. Escalation to surgery was uncommon, with only 5 patients (2.5%) requiring surgical conversion during follow-up. Similarly, only 4 patients (2.0%) required central painkillers. No major patient-reported adverse complaints or serious treatment-related complications were observed.