Comparative Effects of Different Epidural Injection Approaches on Lumbosacral Radicular Pain: A Systematic Review and Network Meta-analysis.

Background: Lumbar disc herniation (LDH) is the main cause of low back pain and/or radiculopathy. Currently, epidural intervention is a widely used and effective conservative treatment method for managing low back and radicular pain caused by LDH.
Objectives: To explore the effectiveness of different epidural injection approaches in adult patients with lumbosacral radicular pain.
Study Design: Systematic review and network meta-analysis (NMA).
Methods: An electronic literature search was performed in the Pubmed, Embase, Cochrane Library, and Web of Science databases. Two authors independently performed data extraction and quality assessment. A Bayesian random effects model was conducted to incorporate the estimates of direct and indirect treatment comparisons and rank the interventions in order. Effect estimates from Bayesian NMA were presented as mean difference (MD) with 95% credible intervals (CrI).
Results: This NMA assessed caudal (C), interlaminar (IL), transforaminal (TF) and parasagittal interlaminar (PIL) epidural injection approaches for lumbosacral radicular pain from 7 trials. A statistically significant treatment difference for pain relief was reported for midline interlaminar (MIL) vs PIL (MD, 1.16; 95%CrI, 0.31-2.06), MIL vs TF (MD, 1.12; 95%CrI, 0.51-1.85), C vs TF (MD, 1.07; 95%CrI, 0.01-2.18) in short-term follow-up and MIL vs TF (MD, 1.8; 95% CrI, 0.3-3.48) in intermediate-term follow-up. For functional improvement, a statistically significant difference was observed with MIL vs PIL (MD, 9.9; 95% CrI, 0.64-19.94) and MIL vs TF (MD, 1.08; 95% CrI, 1.08-17.08) in short-term follow-up. Moreover, the PIL approach and TF appeoach were ranked in the top 2 for pain relief and functional improvement, both in short-term and intermediate-term follow-up.
Limitations: 1) The number of studies included was small; 2) some treatments lacked direct comparisons; 3) only scores from the visual analog scale for pain and the Oswestry Disability Index were included in the result; 4) important outcomes, such as complications, were not included.
Conclusion: In short-term and intermediate-term follow-up, the PIL approach has the highest probability for pain relief and functional improvement.