Retrospective Assessment of Salvage to 10 kHz Spinal Cord Stimulation (SCS) in Patients Who Failed Traditional SCS Therapy: RESCUE Study

Background 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.