Effectiveness of Epiduroscopy for Patients with Failed Back Surgery Syndrome: A Systematic Review and Meta-analysis

Abstract

Introduction: Low-back or leg pain in patients suffering from failed back surgery syndrome (FBSS) is often severe, having a major impact on functionality and quality of life. Despite conservative and surgical treatments, pain can be persistent. An alternative treatment option is epiduroscopy, a minimally invasive procedure based on mechanical adhesiolysis of epidural fibrosis. As epidural fibrosis is speculated to be a major contributor in the pathophysiologic process of FBSS, this review evaluates the effectiveness of epiduroscopy in FBSS patients.

Methods and materials: A systematic literature search was performed in PubMed, Embase, and Cochrane databases. Critical appraisal was performed using validated tools. Meta-analysis was performed using generic inverse variance analysis.

Results: From the 286 identified articles, nine studies were included. The visual analogue scale (VAS) average was 7.6 at baseline, 4.5 at 6, and 4.3 at 12 months. The Oswestry Disability Index (ODI) average was 61.7% at baseline, 42.8% at 6, and 46.9% at 12 months. An average of 49% of patients experienced significant pain relief at 6 and 37% at 12 months. Meta-analysis showed a pooled VAS mean difference of 3.4 (2.6 to 4.1; 95% confidence interval [CI]) and 2.8 (1.6 to 4.0; 95% CI) and pooled ODI mean difference of 19.4% (12.5 to 26.4%; 95% CI) and 19.8% (13.8 to 25.9%; 95% CI) at 6 and 12 months, respectively.

Conclusion: Current literature demonstrates a clinically relevant reduction in pain and disability scores at 6 to 12 months after mechanical adhesiolysis in FBSS patients. The quality of evidence is moderate, and the level of recommendation is weak. Practitioners should consider the benefits of epiduroscopy after weighing the risks for individual patients with FBSS.

Keywords: endoscopic adhesiolysis; epiduroscopy; failed back surgery syndrome; leg pain; recurrent low-back pain; systematic review.

Figure 1

Flowchart of systematic search, performed on November 20, 2019.

Figure 2

Visual analogue scale (A) for each study at baseline and 6 and 12 months after epiduroscopy and (B) box and whisker plot of combined data at baseline, 6, and 12 months after epiduroscopy. M + C, study arm with patients receiving mechanical adhesiolysis with target drug placement; M, study arm with patients receiving only mechanical adhesiolysis.

Figure 3

Forest plot of visual analogue scale mean difference (A) between baseline and 6 months after epiduroscopy, (B) between baseline and 12 months after epiduroscopy, both using the generic inverse variance and random effects analysis model. CI, confidence interval; IV, inverse variance; M, study arm with patients receiving only mechanical adhesiolysis; M + C, study arm with patients receiving mechanical adhesiolysis with target drug placement; SE, standard error.

Figure 4

Oswestry Disability Index (A) for each individual study at baseline and 6 and 12 months after epiduroscopy and (B) combined in box and whisker plot of combined data at baseline and 6 and 12 months after epiduroscopy. M, study arm with patients receiving only mechanical adhesiolysis; M + C, study arm with patients receiving mechanical adhesiolysis with target drug placement.

Figure 5

Forest plot of Oswestry Disability Index mean difference (A) between baseline and 6 months after epiduroscopy and (B) between baseline and 12 months after epiduroscopy, both using the generic inverse variance and random effects analysis model. CI, confidence interval; IV, inverse variance; M, study arm with patients receiving only mechanical adhesiolysis; M + C, study arm with patients receiving mechanical adhesiolysis with target drug placement; SE, standard error.

Figure 6

Scatterplot of percentage (%) of patients experiencing relief of pain according to respective definitions of individual studies at 6‐ and 12‐month follow‐up after epiduroscopy, including average (mean) with trendline.