This prospective investigator-initiated study compares the clinical effectiveness and safety of epiduroscopic adhesiolysis in patients with failed back surgery syndrome (FBSS) and in patients with lumbar radicular pain without prior lumbar surgery. Epiduroscopy allows direct visualization of the epidural space with targeted mechanical adhesiolysis and optional epidural pharmacologic treatment. The primary objective is to evaluate pain relief and functional improvement following the procedure. Secondary outcomes include disability scores, quality of life, and procedure-related complications. The study aims to determine whether prior lumbar surgery influences clinical outcomes after epiduroscopic treatment.

This investigator-initiated prospective, multicenter, randomized, double-blind controlled study was conducted at certified interventional pain centers in Slovakia to evaluate the clinical effectiveness and safety of epiduroscopic adhesiolysis in patients with chronic lumbar radicular pain. The protocol was approved by regional ethics committees, and all participants provided written informed consent. The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice principles.

Eligible participants were adults with chronic lumbosacral radicular pain persisting for more than six months despite conservative treatment. Patients were enrolled into two predefined clinical cohorts according to surgical history: (1) failed back surgery syndrome (FBSS), defined as persistent or recurrent radicular pain following lumbar spine surgery, and (2) surgery-naïve patients without prior lumbar surgery. Cohort allocation was performed prior to randomization, while all other eligibility criteria were identical across groups.

Within each cohort, participants were randomized in a 1:1 ratio to undergo either epiduroscopic mechanical adhesiolysis alone or mechanical adhesiolysis combined with targeted epidural pharmacologic therapy. Randomization was computer-generated and stratified by study center. The study was double-blinded; patients and outcome assessors were unaware of treatment assignment, while the operating physician did not participate in follow-up evaluations.

All procedures were performed via a sacral epidural approach under fluoroscopic guidance using a flexible epiduroscope. Mechanical adhesiolysis consisted of endoscopic dissection and saline irrigation to release epidural adhesions around symptomatic nerve roots. In the pharmacologic treatment groups, adhesiolysis was followed by epidural administration of methylprednisolone acetate (40 mg), hyaluronidase (1,500 IU), and hypertonic saline (10 mL). In the mechanical-only groups, isotonic saline was administered to maintain blinding. Procedural and perioperative management were standardized across centers.

Clinical assessments were performed at baseline and at 6 months after the procedure. Outcomes included pain intensity measured by the Numeric Rating Scale (NRS), health-related quality of life assessed using EQ-VAS and EQ-5D-5L, functional status, analgesic consumption, and procedure-related adverse events. All evaluations were conducted by blinded assessors.

Statistical analyses followed the intention-to-treat principle, and differences between groups and time points were analyzed using appropriate statistical methods.

Inclusion Criteria:

• Age 20-80 years
• Chronic lumbosacral radicular pain persisting ≥ 6 months despite conservative treatment
• Failed back surgery syndrome (FBSS) with history of 1-2 prior lumbar laminectomies or surgery-naïve patients without prior lumbar surgery
• Lower extremity radicular pain with baseline pain intensity ≥ 5 on a 0-10 Numeric Rating Scale
• Ability to understand the study procedures and provide written informed consent

Exclusion Criteria:

• More than two prior lumbar spine surgeries
• Significant spinal pathology other than degenerative disease (e.g., fracture, tumor, infection, inflammatory spondylitis)
• Progressive neurological deficit
• Pregnancy or planned pregnancy during the study period
• Severe systemic illness or contraindication to epidural intervention
• Known allergy to study medications (steroids, hyaluronidase, or saline)
• Inability to complete follow-up assessments
• Any condition judged by investigators to make participation unsafe

Participants and outcome assessors were blinded to treatment allocation. Mechanical-only groups received epidural isotonic saline to maintain blinding. The interventional physician performing the procedure was aware of allocation but was not involved in follow-up assessments or outcome evaluation.