P028: SALVAGE OF LOSS OF EFFECTIVITY IN SCS THERAPY VIA CLOSED LOOP SCS UPGRADE
Daniel Attalla, MD; William Grubb, MD, DDS; Pankti Acharya, DO; Leah Gneco
Rutgers RWJ New Brunswick
Introduction: Spinal cord stimulation (SCS) is an established treatment for intractable chronic pain. It is FDA-approved for the management of post-laminectomy pain, complex regional pain syndrome (CRPS) type I and type II, and neuropathic pain; typically diabetic neuropathy. This procedure involves the placement of electrical leads in the posterior epidural space near the dorsal columns. Although this procedure can lead to long-term pain relief for many individuals, a major problem among these devices is loss of efficacy (LoE). It is estimated that 10% of patients experience LoE at two years following implantation, which leads to device explantation in 43%-73% of those cases. SCS therapy can take advantage of multiple waveforms, such as tonic, closed loop, burst, or high frequency stimulation. More novel waveforms have been used as salvage therapy for patients who experience LoE with traditional waveforms. The objective of this case report is to evaluate whether same-day SCS explant with a SCS trial for salvage can be clinically viable.
Case Report: We present a case of a 65-year-old female with a past medical history of hypertension, hyperlipidemia, diabetes, L5-S1 decompression/fusion, and a tonic open-loop spinal cord stimulator implant. Patient had SCS placed 16 years ago and a battery change after 9 years. Towards the end of life of that battery patient began to have LoE. Patient presented to the clinic with recurrence of lower back pain with radicular symptoms. Patient had previous bilateral leads removed via midline incision with removal of anchors as well. The midline incision was closed and a closed-loop spinal cord stimulator trial was done via a unilateral approach. The previous generator was left implanted. Patient had a successful trial and went for implant a week later and continues with 80% pain relief to date.
Discussion: This case presents upgrading an open loop to a closed loop SCS for salvage therapy. Therefore, we aim to discuss technical factors for salvage therapy in LoE if considering simultaneous upgrade requiring lead replacement for trial. Three important considerations were taken during this patient's trial to facilitate a successful trial. Previous studies have discussed equal efficacy of unilateral versus bilateral lead placement. This case is unique as this patient presents as her own control group for lead placement approach since she had bilateral for her previous SCS and had unilateral for her trial and revision. This was a consideration for wound healing due to explanation at the time of trial. Secondly, the battery was left in during the trial to decrease post op pain and improve likelihood of a successful trial. Lastly, patient selection is a key factor. This patient’s pain was primarily radicular so she was able to distinguish relief during the trial from her post op pain from SCS explant.
Conclusion: This case study adds to a body of evidence that a closed loop is a reasonable treatment to salvage LoE in an open loop SCS. Performing an SCS explant on the same day as an SCS trial can be a viable clinical approach.