Spinal Cord Stimulation for Failed Back Surgery Syndrome: to Trial or Not to Trial?

Spinal cord stimulation (SCS) is a recommended therapy to treat failed back surgery syndrome (FBSS). A trial period is practised to enhance patient selection. However, its fundamental evidence is limited, especially concerning long-term benefit and therapy safety. We compared the long-term (5.3 ± 4.0 years) clinical outcome and therapy safety of a trialled and non-trialled implantation strategy, including multidimensional variables and pain intensity fluctuations over time. A multi-centre cohort analysis was performed in two comparable groups of FBSS patients. Regarding eligibility, patients had to be treated with SCS for at least three months. While the Trial group comprised patients who underwent an SCS implantation after a successful trial, the No-Trial group encompassed patients who underwent complete implantation within one session. The primary outcome measures were pain intensity scores and complications. The Trial and No-Trial groups consisted of 194 and 376 patients(N=570), respectively. A statistically but not clinically significant difference in pain intensity (p=0.003; effect=0.506 (0.172-0.839)) was found in favour of the Trial group. No interaction between a time dependency effect and pain intensity was noted. Whereas trialled SCS patients were more likely to cease opioid usage (p=0.003; OR=0.509 (0.326-0.792)), patients in the No-Trial group endured fewer infections (p=0.006; proportion difference=0.43 (0.007-0.083)). Although the clinical relevance of our findings should be proven in future studies, this long-term real-world data study indicates that patient-centered assessments on whether an SCS trial should be performed have to be investigated. According to the current ambiguous evidence, SCS trials should be considered on a case-by-case basis. PERSPECTIVE: The currently available comparative evidence, together with our results, remains ambiguous on which SCS implantation strategy might be deemed superior. An SCS trial should be considered on a case-by-case basis, for which further investigation of its clinical utility in certain patient populations or character traits is warranted.