RESUMEN
OBJECTIVE: Suppression of back pain with traditional spinal cord stimulation (SCS) in failed back surgery syndrome patients is often insufficient. The objective of this study was to investigate the efficacy of subcutaneous stimulation (SubQ) as ADD-ON therapy to SCS in treating back pain in failed back surgery syndrome patients. MATERIALS AND METHODS: Patients with a minimal pain score of 50 on a 100 mm visual analog scale for both leg and back pain were eligible. If pain reduction after trial SCS was ≥50% for the leg but <50% for the back, patients received additional SubQ leads and were randomized in a 1:1 ratio in a study arm with subcutaneous leads switched on (SubQ ADD-ON) and an arm with subcutaneous leads switched off (Control). The primary outcome was the percentage of the patients, at three months since implantation, with ≥50% reduction of back pain. RESULTS: A total of 97 patients were treated with SCS for leg and back pain. Of these, 52 patients were randomized and allocated to the Control group (n = 24) or to the SubQ ADD-ON group (n = 28). The percentage of patients with ≥50% reduction of back pain was significantly higher in the SubQ ADD-ON group (42.9%) compared to the Control group (4.2%). Mean visual analog scale for back pain, at three months, was a statistically significant 28.1 mm lower in the SubQ ADD-ON group compared to the Control group. CONCLUSION: Subcutaneous stimulation as an ADD-ON therapy to SCS is effective in treating back pain in failed back surgery syndrome patients where SCS is only effective for pain in the leg.
