Long-term outcomes of spinal cord stimulation for refractory phantom limb pain.

OBJECTIVES: Phantom limb pain (PLP) is a disabling post-amputation neuropathic pain condition, and evidence regarding the long-term effectiveness of spinal cord stimulation (SCS) remains limited. This study evaluated trial stimulation outcomes, pain trajectories, device retention, explantation, and device-related complications in patients with refractory PLP. METHODS: We retrospectively reviewed 28 patients with refractory PLP who underwent SCS trial stimulation at our center between June 2010 and September 2023. Baseline characteristics, procedural data, Numeric Rating Scale (NRS) scores, progression to permanent implantation, revision or replacement procedures, and device explantation were recorded. Changes in NRS scores from baseline were assessed, and exploratory regression analyses were performed. RESULTS: Eighteen patients (64%) met the criteria for trial success and proceeded to permanent SCS implantation. In an exploratory analysis, a higher baseline NRS score was associated with trial success. Among the 18 patients with permanent implants, the median follow-up was 78 months. Five SCS systems (28%) were explanted: three because of inadequate pain relief and two after battery depletion without replacement. In a post hoc analysis of the 13 patients who retained their devices at the last available follow-up, the mean NRS score decreased from 8.9 ± 0.8 at baseline to 2.8 ± 0.7 after trial stimulation and was 4.8 ± 0.6 at 1 year, 5.6 ± 1.0 at 2 years, and 6.2 ± 1.1 at the last available follow-up. Three patients underwent planned IPG replacement because of battery depletion, and two underwent unplanned device-related revision procedures. CONCLUSIONS: SCS provided substantial short-term pain relief in selected patients with refractory PLP. However, the magnitude of pain relief diminished over time, and device explantation occurred in a substantial minority of patients, underscoring the need for careful patient selection, long-term follow-up, and device management.