Epidural lysis of adhesions for failed back surgery and spinal stenosis: factors associated with treatment outcome.
BACKGROUND
Failed back surgery syndrome (FBSS) is a challenging problem. One treatment advocated to treat FBSS is epidural lysis of adhesions (LOA). The results of studies examining LOA for FBSS have been mixed, but are limited because no study has ever sought to identify factors associated with outcomes.


METHODS
We performed this multicenter, retrospective study in 115 patients who underwent LOA for FBSS (n = 104) or spinal stenosis (n = 11) between 2004 and 2007. Twenty-seven demographic, clinical, and procedural variables were extracted from medical records and correlated with the outcome, defined as ≥50% pain relief lasting ≥1 month. Univariable analysis was performed, followed by multivariable logistic regression.


RESULTS
Overall, 48.7% (95% confidence interval [CI], 39.3%-58.1%) of patients experienced a positive outcome. In univariable analysis, those who had a positive outcome were older (mean age 64.1 years; 95% CI, 59.7-68.6 vs 57.2; 95% CI, 53.0-61.4 years; P = 0.02), while higher baseline numerical rating scale pain scores were associated with a negative outcome (mean 6.7 years; 95% CI, 6.0-7.3 vs 7.5; 95% CI, 6.9-8.0; P = 0.07). Use of hyaluronidase did not correlate with outcomes in univariable analysis (odds ratio [OR], 1.2; 95% CI, 0.6-2.5; P = 0.65). In multivariable analysis, age ≥81 years (OR, 7.8; 95% CI, 1.4-53.7), baseline numerical rating scale score ≤9 (OR, 4.4; 95% CI, 1.4-16.3, P = 0.02), and patients on or seeking disability or worker's compensation (OR, 4.4; 95% CI, 1.1-19.5, P = 0.04) were significantly more likely to experience a positive outcome.


CONCLUSIONS
Considering our modest success rate, selecting patients for epidural LOA based on demographic and clinical factors may help better select treatment candidates. Procedural factors such as the use of hyaluronidase that increase risks and costs did not improve outcomes, so further research is needed before these become standard practice.