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.
A randomized controlled trial to analyze the clinical efficacy of
percutaneous epidural lysis of adhesions in chronic radicular
Prospective randomized placebo controlled interventional trial.
Power calculation based on a feasibility trial.
Medical university centers.
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.
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.
Specific effects of single treatment components cannot be specified
because there was no imaging examination after treatment.
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.