A Review of Emerging Evidence for Utilization of a Percutaneous Interspinous Process Decompression Device to Treat Symptomatic Lumbar Adjacent-Segment Degeneration.

OBJECTIVE: Postlaminectomy syndrome diagnoses secondary to adjacent segment degeneration are a substantial and rising cause of morbidity in the United States. Emerging spinal cord neuromodulation technologies have produced successful outcomes for postlaminectomy neuropathic pain but are less effective in treating neurogenic claudication secondary to recurrent lumbar stenosis. Percutaneous interspinous process decompression systems can be used as a salvage treatment modality for persistent structural neurogenic claudication in postlaminectomy syndrome or after spinal cord stimulator implantation. METHODS: This paper is a review of emerging evidence for efficacious utilization of percutaneous interspinous process decompression. RESULTS: A recent pragmatic trial of subjects who underwent percutaneous interspinous process decompression for lumbar stenosis with intermittent neurogenic claudication reported that 63% (26/41) maintained minimal clinically important improvement in visual analog scale (VAS) leg pain, 61% (25/41) in VAS back pain, 78% (32/41) in function objective values, and 88% (36/41) reported satisfaction with treatment at 12 months postop. All subjects in a small case series of seven individuals with postlaminectomy adjacent-segment disease reported postoperative satisfaction scores of 3 or 4 on a 0-4 scale and were also able to decrease or wean completely off controlled pain medications. In another study, there was a significant decrease in average leg pain (60% improvement, P < 0.0001, N = 25) and axial low back pain (58% improvement, P < 0.0001, N = 25) in patients who underwent one- or two-level percutaneous interspinous process decompression as a rescue treatment for reemerging neurogenic claudication after spinal cord stimulator implantation. CONCLUSIONS: The spine often is a focus of progressive disease. Furthermore, mechanical changes associated with spinal instrumentation can lead to additional disease at adjacent levels. Many individuals will present with symptomatic neurogenic claudication recalcitrant to multimodal management strategies, including even the most sophisticated neuromodulation technologies. Implementation of salvage percutaneous interspinus process decompression implantation in cases of adjacent segment degeneration or incomplete spinal cord stimulation can decompress structural causes of neurogenic claudication while sparing the patient from more invasive surgical reoperation techniques.

DRG FOCUS: A Multicenter Study Evaluating Dorsal Root Ganglion Stimulation and Predictors for Trial Success.

INTRODUCTION: Dorsal root ganglion stimulation (DRGS) is a powerful tool in the treatment of chronic, neuropathic pain. The premise of DRGS is similar to that of conventional spinal cord stimulation (cSCS), however, there is more variability in how it can be utilized. While it is this variability that likely gives it its versatility, DRGS is not as straightforward to implement as cSCS. The purpose of this study was to assess the efficacy of DRGS on a broad number of diagnoses, determine which dorsal root ganglia were associated with better outcomes for particular body parts/diagnoses, and evaluate what factors/parameters were associated with higher rates of trial success. METHODS: This is a physician initiated, multicenter retrospective registry of 217 patients trialed with DRGS. Data were collected via an online questionnaire that assessed specifics regarding the patient's pain, distribution, size, and response to treatment. The data were analyzed to see if there were certain diagnoses and/or parameters that were more or less associated with trial success. RESULTS: DRGS was found to be an effective treatment in all diagnoses evaluated within this study, most of which had statistically significant improvements in pain. The most important predictor of trial success was the amount of painful area covered by paresthesias during the programing phase. The number of leads utilized had a direct and indirect impact on trial success. Pain in the distribution of a specific peripheral nerve responded best and there was no statistical difference based on what body part was being treated. CONCLUSION: DRGS can be an effective treatment for a variety of neuropathic pain syndromes, in addition to CRPS. It is recommended that a minimum of 2 leads should be utilized per area being treated. In addition, this therapy was shown to be equally efficacious in any body part/region so long as the area being treated is focal and not widespread.

The Neuromodulation Appropriateness Consensus Committee on Best Practices for Dorsal Root Ganglion Stimulation.

INTRODUCTION: The Neuromodulation Appropriateness Consensus Committee (NACC) is dedicated to improving the safety and efficacy of neuromodulation and thus improving the lives of patients undergoing neuromodulation therapies. With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion (DRG) stimulation has significantly improved the treatment of complex regional pain syndrome (CRPS), among other conditions. Through funding and organizational leadership by the International Neuromodulation Society (INS), the NACC reconvened to develop the best practices consensus document for the selection, implantation and use of DRG stimulation for the treatment of chronic pain syndromes. METHODS: The NACC performed a comprehensive literature search of articles about DRG published from 1995 through June, 2017. A total of 2538 article abstracts were then reviewed, and selected articles graded for strength of evidence based on scoring criteria established by the US Preventive Services Task Force. Graded evidence was considered along with clinical experience to create the best practices consensus and recommendations. RESULTS: The NACC achieved consensus based on peer-reviewed literature and experience to create consensus points to improve patient selection, guide surgical methods, improve post-operative care, and make recommendations for management of patients treated with DRG stimulation. CONCLUSION: The NACC recommendations are intended to improve patient care in the use of this evolving therapy for chronic pain. Clinicians who choose to follow these recommendations may improve outcomes.

BURST(able): A Retrospective, Multicenter Study Examining the Impact of Spinal Cord Stimulation with Burst on Pain and Opioid Consumption in the Setting of Salvage Treatment and "Upgrade".

BACKGROUND: Loss of efficacy (LOE) is a well-known phenomenon associated with spinal cord stimulation (SCS) and is the leading cause of explant. Although recent advances in neuromodulation have resulted in a decreased incidence of LOE, it still occurs. Intuition suggests that when LOE ensues, switching to a different SCS therapy/platform could potentially be a viable clinical option; however, there are no data presently available to validate this theory. OBJECTIVES: The primary objective was to evaluate the efficacy of SCS therapy rotation with DeRidder Burst on reversing LOE. A subobjective was to evaluate the hypothesis that the body will treat a novel waveform as a "different therapy" when introduced for the first time, regardless of the setting. STUDY DESIGN: Multicenter, retrospective. SETTING: Private practice. METHODS: A total of 307 patients with ongoing SCS therapy had a de novo therapy conversion to DeRidder Burst via surgical revision or software upgrade. Each cohort was split into 2 additional arms/subcohorts: those who were failing their SCS (salvage) versus those who were reporting success with their SCS system but were looking for increased pain relief (upgrade). This study was physician-directed and not commercially funded. RESULTS: There were statistically significant reductions in Numeric Rating Scale, percent pain relief in both surgical revision and software upgrade arms. A statistical reduction in opioid dosing was seen in the overall population and the salvage group. Larger reductions in pain/opioid consumption were observed in the surgically revised group when the revision was performed earlier. Subgroup analysis showed both salvage and upgrade groups restored treatment efficacy irrespective of time or the previous frequency/waveform. LIMITATIONS: The retrospective nature of the study and the inability to eliminate potential confounding variables when evaluating the use of opioids in the study population. CONCLUSIONS: LOE is an unfortunate occurrence with few evidence-based solutions presently available to reverse it. Our findings suggest that implementing D-Burst stimulation may be an effective option for treating LOE, as well as potentially reducing opioid consumption, regardless of the prior SCS system.