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Introduction: Traditional spinal cord stimulation (t‐SCS) has been used to treat chronic pain for over 50 years. However, up to 30% of patients undergo explant, with the main indication being loss of efficacy (LoE), and few alternative treatment options exist for these patients. Strategies to mitigate LoE commonly include conversion to another type of SCS (termed 'salvage' or 'rescue'). This review summarizes the existing literature concerning the efficacy and safety of 10 kHz SCS as a salvage therapy. Methods: We searched PubMed, the Cochrane Library, ClinicalTrials.gov, and other sources between January 2009 and April 2021. Records were retained if the authors reported clinical outcomes with a minimum of ≥ 3 months of follow‐up in patients implanted with a Senza® 10 kHz SCS system in an effort to treat t‐SCS LoE. Results: Ten articles were eligible for inclusion, reporting 3 prospective studies and 7 retrospective reviews. In the single study that salvaged patients without a repeat trial prior to surgery, 81% of patients were responders (≥ 50% pain relief from baseline), with mean pain relief of 60%. Among repeat‐trial studies, the responder rate ranged from 46% to 80%, and mean pain relief from 47% to 68%. No unanticipated therapy‐related safety issues were reported among the included articles. Conclusion: Preliminary data suggest that chronic back and/or leg pain patients with t‐SCS LoE can experience improved and durable pain relief after conversion to 10 kHz SCS. However, additional research is needed to define predictors of success and establish whether salvage without a repeat trial is a viable conversion method. [ABSTRACT FROM AUTHOR]

Leonardo Kapural,1 Dawood Sayed,2 Brian Kim,2 Caroline Harstroem,1 James Deering1 1Carolinas Pain Institute, Winston-Salem, NC 27103, USA; 2Department of Anesthesiology, University of Kansas, Kansas City, KS, USACorrespondence: Leonardo Kapural Email lkapuralmd@gmail.comBackground and Objectives: A randomized clinical trial demonstrated that 10 kHz SCS (10kHz-SCS) therapy is superior to traditional low-frequency SCS (LF-SCS) at 12- and 24-month clinical follow-ups and led to Food and Drug Administration (FDA) approval of the therapy. The results of the study led our practices to trial 10kHz-SCS in patients who had not maintained pain relief with LF-SCS therapy. Here, we report a large set of data from two clinical sites to assess if 10kHz-SCS is an effective salvage modality when LF-SCS fails.Methods: We conducted a retrospective chart review of 120 patients across two clinical sites who had LF-SCS implants and were salvaged with 10kHz-SCS.Results: Data were analyzed from 105 patients between 28 and 90 years old (median 60) with chronic pain for 13.6 years. The mean duration of LF-SCS therapy was 4.66± 3.9 years. The average Visual Analog Scale (VAS) decreased from 8.30± 1.4 (median of 8) cm to 3.32± 2.0 (median of 3) cm at 12 months and 3.36± 2.0 (median of 3) cm at the most recent clinic visit (p< 0.001) following salvage therapy. Pain relief of 50% or more was obtained in 85 out of 105 (81%) patients. Opioid usage decreased from 60.3± 77.1 mg to 32.1± 44.0 mg MSO4 equivalents (p = 0.001) at 12 months after salvage therapy.Conclusion: Eighty-one percent of patient cases reviewed, where LF-SCS had failed, achieved > 50% pain relief with 10kHz-SCS, and almost all exhibited some clinical improvement. Therefore, 10kHz-SCS should be considered an appropriate option to rescue failed LF-SCS.Keywords: spinal cord stimulation, high-frequency 10 kHz spinal cord stimulation, low-frequency spinal cord stimulation, neuromodulation, lower back pain, lumbosacral radiculopathy, post-laminectomy syndrome, failed back surgery syndrome