Combination therapy with simultaneous delivery of spinal cord stimulation modalities: COMBO randomized controlled trial.

Aim: The Combining Mechanisms for Better Outcomes randomized controlled trial assessed the effectiveness of various spinal cord stimulation (SCS) modalities for chronic pain. Specifically, combination therapy (simultaneous use of customized sub-perception field and paresthesia-based SCS) versus monotherapy (paresthesia-based SCS) was evaluated. Methods: Participants were prospectively enrolled (key inclusion criterion: chronic pain for ≥6 months). Primary end point was the proportion with ≥50% pain reduction without increased opioids at the 3 month follow-up. Patients were followed for 2 years. Results: The primary end point was met (n = 89; p < 0.0001) in 88% of patients in the combination-therapy arm (n = 36/41) and 71% in the monotherapy arm (n = 34/48). Responder rates at 1 and 2 years (with available SCS modalities) were 84% and 85%, respectively. Sustained functional outcomes improvement was observed out to 2 years. Conclusion: SCS-based combination therapy can improve outcomes in patients with chronic pain. Clinical Trial Registration: NCT03689920 (ClinicalTrials.gov), Combining Mechanisms for Better Outcomes (COMBO).

Spinal cord stimulation (SCS) is a device-based therapy for chronic pain that delivers electrical impulses to the spinal cord, disrupting pain signals to the brain. Pain relief can be achieved using different SCS techniques that use or do not use paresthesia (stimulation that produces a tingling sensation). These approaches affect patients in different ways, suggesting that different biological processes are involved in enabling pain relief. Research also suggests that better long-term results occur when patients can choose the therapy that is best for their own needs. This clinical study compared pain relief and other functional activities in those receiving combination therapy (simultaneous use of SCS that does and does not produce tingling sensation) against those receiving monotherapy (only SCS therapy producing tingling sensation) for 3 months. In the study, 88% of those receiving combination therapy and 71% with monotherapy alone reported a 50% (or greater) decrease in overall pain (the 'responder rate') without an increased dose of opioid drugs at 3 months after the start of therapy. This responder rate was found to be 84% at 1 year and 85% at 2 years (with all SCS therapy options available). Analysis of functional activities or disability showed that patients improved from 'severely disabled' at study start to 'moderately disabled' after 2 years, indicating that effective long-term (2 year) improvement can be achieved using SCS-based combination therapy for chronic pain.

Cooled and traditional thermal radiofrequency ablation of genicular nerves in patients with chronic knee pain: a comparative outcomes analysis.

INTRODUCTION: Genicular nerve radiofrequency ablation (GNRFA) is a minimally invasive intervention for patients with chronic knee pain (CKP) not responding to conservative treatments. Few investigations have compared treatment outcomes of cooled-RFA (c-RFA) and thermal-RFA (t-RFA), two common approaches of GNRFA. This study aims to investigate and compare outcomes, including probability of treatment success, between c-RFA and t-RFA in patients with CKP. METHODS: This retrospective cohort study analyzed a total of 208 propensity score matched patients, including 104 patients who received c-RFA and 104 patients who received t-RFA. The primary outcome was probability of pain relief after the procedure, defined as reduction in Numeric Rating Scale (NRS) pain score of 2 or greater. The secondary outcomes were degree of NRS pain score reductions, duration of relief, and the probability of patients receiving TKA within 1 year of treatment. RESULTS: T-RFA was associated with a higher probability of pain relief within 1, 3, and 6 months after procedure when compared with c-RFA. Probabilities of pain relief from t-RFA and c-RFA were 62% (95% CI 51% to 71%) and 43% (95% CI 34% to 53%; p=0.01) within 1 month, 78% (95% CI 68% to 85%) and 55% (95% CI 45% to 64%; p<0.001) within 3 months, and 79% (95% CI 70% to 86%) and 59% (95% CI 49% to 68%; p<0.01) within 6 months, respectively. t-RFA was also associated with greater mean NRS pain score reduction at 1 month after procedure: -4.71 (95% CI -5.3 to -4.1) when compared with -3.59 (95% CI -4.3 to -2.9; p=0.02) from c-RFA. T-RFA and c-RFA were comparable in pain score reduction at 3, 6, 9 and 12 months after procedure. Both groups demonstrated comparable duration of relief and probability of patients receiving TKA within 1 year. DISCUSSION: Both t-RFA and c-RFA effectively reduced NRS pain scores in most patients with CKP within the 1 year follow-up period. Genicular nerve t-RFA was associated with a higher probability of treatment success and a greater degree of pain relief at 1 month after the procedure when compared with c-RFA in propensity score matched patients with CKP.

Multi-waveform Spinal Cord Stimulation with High Frequency Electromagnetic Coupled (HF-EMC) Powered Implanted Electrode Array and Receiver for the Treatment of Chronic Back and Leg Pain (SURF Study).

BACKGROUND: Novel externally powered spinal cord stimulation technology can be fully implanted when trialing the effectiveness of the therapy, since no percutaneous leads are needed, and the trial period lasted 30 days. Multiple tests of different stimulation modalities and parameters are possible, thus improving the chances that the therapy will lead to effective pain reduction. OBJECTIVES: The objective of this study was to analyze the effectiveness of the Freedom Spinal Cord Stimulator System (Stimwave LLC, Pompano Beach, FL) for the treatment of failed back surgery syndrome due to postlaminectomy syndrome utilizing multiple waveforms. STUDY DESIGN: This was a prospective, single cohort study. Patients were enrolled and implanted with up to 2 permanent, 8-contact electrode arrays with receiver, controlled regularly during 6 months of follow-up after a one month trial period. Pain and overall improvement were evaluated at 3 months and 6 months following an initial one-month implanted trial period. SETTINGS: A variety of frequency stimulation waveforms (tonic as well as subthreshold) at frequencies of 10 Hz to 1500 Hz* and 50 to 800 µs pulse width, were provided. (*Note: While 1500 Hz was utilized in the study, Stimwave Technologies is currently only permitted to provide spinal cord stimulation therapy at frequencies below 1500 Hz, therefore pulse rates used in this study are not commercially available on Stimwave Technologies' products). METHODS: Endpoints evaluated included the Visual Analog Scale (VAS) for pain intensity, Oswestry Disability Index (ODI) for functionality, Patient Global Impression of Change (PGIC) for overall health improvement, and quality of life as measured by the European Quality of Life 5 Dimension questionnaire (EQ-5D-5L). RESULTS: Thirty-nine patients completed the study. At 6 months, the responder rate (? 50% reduction VAS for back pain) was 33/39 = 85%. Mean VAS for back pain decreased 62%. The mean ODI decreased 46% from 54 to 29.2, indicating a reduction from severe to moderate disability. The median satisfaction as measured with the PGIC was 6 out of 7. The mean EQ-5D-5L utility score increased from 0.54 to 0.75. At the 6-months endpoint, 44% (17/39) of patients preferred tonic stimulation with a back pain per protocol responder rate of 82%; 41% (16/39) preferred surge with a responder rate of 56%; and 15% (6/39) preferred high density, with a responder rate of 83%. Fifteen patients reported 28 adverse events. Migration of the electrode array (n = 10) was the adverse event most reported. Two serious adverse events related to infection were reported. LIMITATIONS: This study had several limitations. Trial failures were excluded from the analysis, there was a small sample size, and there was a lack of blinding due to the suprathreshold nature of tonic stimulation. CONCLUSION: The study demonstrates that spinal cord stimulation with multiple stimulation patterns demonstrates clinical and functional efficacy when using an externally powered stimulation system.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations on Best Practices for Cervical Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise with international representation to establish evidence-based guidance on the use of neurostimulation in the cervical region to improve outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for an often-overlooked area of neurostimulation practice. MATERIALS AND METHODS: Authors were chosen based upon their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to the present. Identified studies were graded using the US Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the use of cervical neuromodulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be utilized as a guide to assist decision making when clinically appropriate.

Combined Bipolar and V-Shaped Lesions for Lumbar Facet Radiofrequency Ablation: A Technical Report.

INTRODUCTION: Radiofrequency ablation (RFA) is a demonstrated safe and effective treatment for chronic low back pain. RFA delivers high density electrical current near lumbar medial branch nerve. The success of RFA is contingent upon creating a lesion that overlaps the sensory nerve supplying the affected facet joint(s). Both bipolar-RFA and V-shaped active tip cannulas increase lesion size in experimental models. We describe successful application of concomitant bipolar and V-shaped lesions in a single patient with chronic low back pain caused by lumbar spondylosis. CASE PRESENTATION: An 81-year-old male with atrial fibrillation on chronic warfarin anticoagulation was previously treated with conventional monopolar lumbar facet RFA resulting in a 75% decrement in pain intensity exceeding eight months. Nine months after the procedure, his pain returned with similar pretreatment character and was unresponsive to additional physical therapy and acetaminophen. We elected to use a V-shaped cannula to maximize lesion diameter and lengthen intervals between anticoagulant abstinence to minimize the risk. Intraoperatively, a grounding-pad malfunction compelled us to convert to bipolar-RFA by placing a second adjacent V-shaped cannula, eliminating grounding-pad requirement. Bilateral bipolar medial branch RFA of L3-L4, L4-L5, L5-S1 nerves was performed between these two cannulas without further incident. The patient had sustained analgesia that lasted over twelve months resultant from treatment. CONCLUSIONS: We herein describe a technique of combined bipolar-RFA utilizing proximally adjacent V-shaped cannulas. Both bipolar and V-shaped cannulas create larger lesions in experiments. While both techniques purport theoretical advantages, the clinical superiority of a combined technique warrants continued clinical investigation.

Association Between Oral Pain Medications and Intrathecal Opioid Dose Escalation: A Retrospective Analysis.

OBJECTIVES: Patients treated with intrathecal therapy frequently require opioid dose increases to maintain analgesia. The kinetics of intrathecal opioid dose escalation are poorly understood. We hypothesized that antidepressant use, antiepileptic use, and lower baseline oral opioid intake prior to intrathecal pump implantation will be protective against intrathecal opioid dose escalation. MATERIALS AND METHODS: Targeted drug delivery medication doses were collected from patients who had an intrathecal pump implanted between 2007 and 2016. From a sample size of 136 patients, the association between antidepressant, antiepileptic, and oral opioid use with intrathecal dose escalation was assessed using statistical models. RESULTS: Individuals using an antiepileptic had an estimated ratio of means (97.5% CI) of opioid consumption of 0.91 (97.5% CI: [0.48, 1.73], p = 0.74) at six months, 0.83 ([0.43, 1.58], p = 0.51) at 12 months, and 0.77 ([0.40, 1.45], p = 0.36) at 24 months. Patients prescribed antidepressants had an estimated ratio of means (97.5% CI) of 1.43 ([0.77, 2.65], p = 0.19) at six months, 1.41 ([0.76, 2.63], p = 0.22) at 12 months, and 1.33 ([0.70, 2.51], p = 0.31) at 24 months. In our secondary analysis of pre-implant oral opioid use, patients treated with high oral opioid doses had a similar pattern of intrathecal dose escalation when compared to patients using low doses of oral opioids. CONCLUSIONS: Use of antiepileptics, antidepressants, or low oral opioid doses was not associated with attenuation of intrathecal dose escalation. Intrathecal opioid dose escalation was observed to occur similarly, regardless of baseline oral analgesics concomitantly employed.

Longevity and Utilization Cost of Rechargeable and Non-Rechargeable Spinal Cord Stimulation Implants: A Comparative Study.

INTRODUCTION: Despite major advancements in features and capabilities of the implantable pulse generator (IPG), real-life longevity and cost-effectiveness studies to guide pain specialists to make the appropriate choice between rechargeable and non-rechargeable IPG are limited. Our study aimed to compare the longevity and cost effectiveness of rechargeable vs. non-rechargeable IPG and SCS systems. METHODS: Data were collected for all SCS implantations performed between 1994 and 2018. The primary goal was to determine IPG longevity, defined as the time interval between IPG implantation and elective replacement due to IPG end of life (EOL). On the other hand, SCS system longevity was defined as the time between SCS implantation and its removal or revision for any reason other than IPG EOL. Kaplan-Meier and log-rank tests were used to assess IPG and SCS system longevities. Cost analysis was performed for cost effectiveness. RESULTS: The median IPG longevity was significantly higher for rechargeable SCS devices than for non-rechargeable SCS devices (7.20 years and 3.68 years, respectively). The median cost per day was similar for both IPGs, $13.90 and $13.81 for non-rechargeable and rechargeable, respectively. The median cost for SCS systems was higher for the rechargeable group ($60.70) compared with the non-rechargeable group ($31.38). CONCLUSIONS: Rechargeable IPG had increased longevity compared to their non-rechargeable counterparts, yet there was no significant difference in the actual longevity due to premature revisions or explantations between both SCS systems. Furthermore, non-rechargeable SCS systems were found to be the more cost-effective option when compared with rechargeable SCS systems.