Percutaneous Epidural Lysis of Adhesions in
Chronic Lumbar Radicular Pain: A Randomized,
Double-Blind, Placebo-Controlled Trial
Authors: Gerdesmeyer Ludger 
Published: March 2021

Background: Chronic radicular pain can occur after disc pathology and failed back surgery. An
evidence-based effective therapeutic option is not available nor does a gold standard exist.
Objectives: A randomized controlled trial to analyze the clinical efficacy of percutaneous epidural
lysis of adhesions in chronic radicular pain.
Study Design: Prospective randomized placebo controlled interventional trial. Power calculation
based on a feasibility trial.
Setting: Medical university centers.
Methods: Within 4 years a total of 381 patients with chronic radicular pain lasting longer than
4 months which failed to respond to conservative treatments were screened and 90 patients were
enrolled. They were randomly assigned to receive either percutaneous neurolysis or placebo with
concealed allocation in permuted blocks of 4 to 8, stratified by treatment center. The primary
outcome measure was the differences in percent change of Oswestry Disability Index (ODI) scores 3
months after intervention. Secondary outcome measures were difference in percent change of ODI
scores and Visual Analog Scale (VAS) 6 and 12 months after intervention and success rates defined
as at least 50% reduction in ODI scores and VAS scores (mean change from baseline) at 3, 6, and
12 months after treatment. Explorative, 2-sided group comparisons for baseline characteristics
between active treatment and controls were done using the t-test for 2 independent samples for
quantitative data and Fisher’s exact test for binary data.
Results: The ODI and VAS scores as well as the success rates for ODI vs VAS were significantly
better 3, 6, and 12 months in the lysis group vs the control group. The ODI in the lysis group
improved from 55.3 ± 11.6 to 26.4 ± 10.8 after 3 months. The placebo group improved from
55.4 ± 11.5 to 41.8 ± 14.6 (P < 0.01). VAS improved from 6.7 ± 1.1 to 2.9 ± 1.9 in the active
group and from 6.7 ± 1.1 to 4.8 ± 2.2 (P < 0.01) after placebo. Twelve month follow-up shows
further improvement, the differences remain significant. In multiple linear regression, forward
and backward variable selection methods resulted in the same covariate model confirming the
univariate result for group comparison in the primary analysis. No severe side effects occurred but
minor transient neurological effects such as partial sensomotoric deficits did. One dura puncture
and one catheter displacement were found.
Limitations: Specific effects of single treatment components cannot be specified because there
was no imaging examination after treatment.
Conclusion: Based on the findings of our study as well as other studies, we believe the minimally
invasive percutaneous adhesiolysis procedure should be the first choice treatment option for
patients with chronic lumbosacral radicular pain who present with clinical history and findings
similar to those of the patients enrolled in our study.
Key words: Lysis, low back pain, randomized controlled trial (RCT), placebo, epidural,
radiculopathy, outcome, evidence-based medicine