Defining Short- and Long-Term Programming Requirements in Patients Treated With 10-kHz Spinal Cord Stimulation.

OBJECTIVES: High-frequency spinal cord stimulation (10-kHz SCS) has been shown to be an effective treatment for refractory low back pain and neck pain with and without limb pain in clinical trial and real-world studies. However, limited information is available in the literature on the type and frequency of programming parameters required to optimize pain relief. MATERIALS AND METHODS: Retrospective trial and postimplant clinical and system device data were analyzed from consecutive patients with neck pain and low back pain, with and without limb pain, from a single clinical site, including both thoracic and cervical lead placement. Best bipole, stimulation parameters, and outcomes, including pain relief, change in opioid medication use, sleep, and daily function, were analyzed. RESULTS: Of the 92 patients in the trial, 70 received a permanent implant. Of these, the mean duration of follow-up was 1.8 ± 1.3 years. Pain relief of ≥50% at the last follow-up was achieved by 64% of patients implanted; in addition, 65% reduced their opioid medication use; 65% reported improved sleep, and 71% reported improved function. There was some consistency between the "best" bipole at trial and permanent implant, with 82% of patients within one bipole location, including 54% of permanent implants who were using the same best bipole as at trial. After permanent implant, device reprogramming was minimal, with ≤one reprogramming change per patient per quarter required to maintain pain outcomes. CONCLUSIONS: In the study, 10-kHz SCS was an effective therapy for treating chronic pain, whereby a high responder rate (≥50% pain relief) was achieved with short time to pain relief in trial and maintained with limited device programming after permanent implant. The data presented here provide insight into the programming required during the trial and implant stages to obtain and maintain therapeutic efficacy.

Prevalence of Staphylococcus aureus Colonization in Spinal Cord Stimulator Surgical Procedures.

OBJECTIVES: To determine the prevalence of Staphylococcus aureus (S aureus) colonization for spinal cord stimulation (SCS) surgical patients and to identify specific at-risk patient populations. MATERIALS AND METHODS: Following Institutional Review Board approval, a retrospective review identified 232 SCS surgical patients. Preoperative Saureus nasal swab results were reviewed. Preoperative characteristics that included age at the time of procedure, body mass index, and medical comorbidities including, but not limited to, diabetes, smoking, obesity, and a history of surgical site infections were identified for each patient. The Clopper-Pearson method was used to calculate 95% CIs for proportions, and Fisher exact tests were used to estimate odds ratios (95% CI) for patient characteristics. RESULTS: The 232 SCS surgical patients who were identified underwent 396 unique neuromodulation procedures, with 100% screened for methicillin-resistant Saureus (MRSA) and 98.3% screened for methicillin-sensitive Saureus (MSSA). Overall, 23.3% (n = 54/232, 95% CI: 18.0%-29.3%) of patients were preoperatively colonized with Saureus, according to the following classification: 4.3% (n = 10/232, 95% CI: 2.1%-7.8%) were positive for MRSA and 20.2% (n = 46/228, 95% CI: 15.2%-26.0%) were positive for MSSA. Two patients were colonized with both MRSA and MSSA. Furthermore, 95.7% (n = 44/46, 95% CI: 85.2%-99.5%) of patients that were MSSA colonized were MRSA negative. Analysis of independent patient characteristics revealed anxiety and hypothyroidism as the only conditions associated with significantly increased odds of MRSA and MSSA colonization, respectively. CONCLUSIONS: Staphylococcusaureus colonization was present in >20% of SCS patients, with MSSA carriage occurring at a rate nearly five times that of MRSA. MRSA screening alone would not have identified >90% of Saureus-colonized patients with only MSSA carrier status. Therefore, consideration should be given to preoperative screening for both MRSA and MSSA. Since limited patient characteristics were associated with greater risk for Saureus colonization, all patient populations should be screened.

Multiphase Spinal Cord Stimulation in Participants With Chronic Back or Leg Pain: Results of the BENEFIT-02 Randomized Clinical Trial.

OBJECTIVE: This study aimed to assess the safety and effectiveness of a new charge-distributed multiphase stimulation paradigm during an extended spinal cord stimulation (SCS) trial. MATERIALS AND METHODS: This prospective, multicenter, randomized, single-blind, feasibility study included participants with chronic low back and/or leg pain and baseline numerical rating scale (NRS) for overall pain intensity ≥6. After a successful commercial SCS trial, participants were randomized to multiphase SCS therapy A (approximately 600-1500 Hz) or B (approximately 300-600 Hz), delivered via an investigational external pulse generator and existing leads during an 11-to-12-day testing period. Primary end points were mean NRS change from baseline to final in-office visit for each multiphase therapy and between therapies. Secondary end points included mean NRS change from end of commercial trial to final study visit and incidence of device-related adverse events (AEs). Additional measures included patient-reported outcomes collected at home through electronic watches and written diaries. Power usage was compared between multiphase and commercial therapies. RESULTS: A total of 122 participants initiated a commercial trial; 77 were randomized to a multiphase arm, and 65 completed the study. Reductions in mean NRS scores from baseline to final study visit were significant for multiphase therapy A and B (-4.3 and -4.7, respectively; both p < 0.0001). There was no statistically significant difference in mean NRS reduction or percent pain relief between multiphase therapies. In an additional analysis, 63.9% of participants reported greater pain relief with multiphase than with commercial SCS therapy in the at-home setting. On average, multiphase required less power than did commercial devices. One non-serious device-related AE was reported, and no infections occurred during the extended trial. CONCLUSIONS: Multiphase SCS effectively reduced pain in participants with chronic low back and/or leg pain during a trial, with no unanticipated device-related AEs reported. Future studies should evaluate long-term effectiveness of multiphase stimulation. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03594266.

High-frequency (10 kHz) spinal cord stimulation (SCS) as a salvage therapy for failed traditional SCS: A narrative review of the available evidence.

INTRODUCTION: Traditional spinal cord stimulation (t-SCS) has been used to treat chronic pain for over 50 years. However, up to 30% of patients undergo explant, with the main indication being loss of efficacy (LoE), and few alternative treatment options exist for these patients. Strategies to mitigate LoE commonly include conversion to another type of SCS (termed 'salvage' or 'rescue'). This review summarizes the existing literature concerning the efficacy and safety of 10 kHz SCS as a salvage therapy. METHODS: We searched PubMed, the Cochrane Library, ClinicalTrials.gov, and other sources between January 2009 and April 2021. Records were retained if the authors reported clinical outcomes with a minimum of ≥ 3 months of follow-up in patients implanted with a Senza® 10 kHz SCS system in an effort to treat t-SCS LoE. RESULTS: Ten articles were eligible for inclusion, reporting 3 prospective studies and 7 retrospective reviews. In the single study that salvaged patients without a repeat trial prior to surgery, 81% of patients were responders (≥ 50% pain relief from baseline), with mean pain relief of 60%. Among repeat-trial studies, the responder rate ranged from 46% to 80%, and mean pain relief from 47% to 68%. No unanticipated therapy-related safety issues were reported among the included articles. CONCLUSION: Preliminary data suggest that chronic back and/or leg pain patients with t-SCS LoE can experience improved and durable pain relief after conversion to 10 kHz SCS. However, additional research is needed to define predictors of success and establish whether salvage without a repeat trial is a viable conversion method.

Pulse Dosing of 10-kHz Paresthesia-Independent Spinal Cord Stimulation Provides the Same Efficacy with Substantial Reduction of Device Recharge Time.

OBJECTIVE: This study was designed to assess whether using pulse dosing (PD) (regularly cycled intermittent stimulation) of high-frequency 10-kHz spinal cord stimulation (10-kHz SCS) can reduce device recharge time while maintaining efficacy in patients with chronic intractable back pain with or without leg pain. DESIGN: Prospective, multicenter, observational study. METHODS: Patients successfully using 10-kHz SCS at 100%ON (i.e., continuously with no PD) for >3 months were consecutively enrolled. After a 1-week baseline period of documenting their pain twice daily on a 0-10 numerical rating scale (NRS) using 100%ON of their "favorite" program, all subjects were reprogrammed to 14%PD for 10-14 days. If subjects preferred 14%PD to 100%ON, they were programmed to 3%PD; otherwise, they were programmed to 50%PD. Subjects used this next program for another 10-14 days. Subjects then entered a 3-month observational period during which they were requested to use but not limited to their most preferred %PD program. Toward the end of 3 months, subjects completed a 7-day NRS diary and indicated a final %PD program preference. Study endpoints included %PD preference, mean diary NRS by %PD, and daily minutes and patterns of charging. RESULTS: Of 31 subjects completing the study, 81% preferred less than 100%ON. Among the subjects, 39% preferred 3%PD, 32% preferred 14%PD, 10% preferred 50%PD, and 19% preferred 100%ON. Average daily charge durations were 8.3 ± 3.1 minutes for 3%PD, 13.9 ± 4.9 minutes for 14%PD, 26.2 ± 7.4 minutes for 50%PD, and 43.8 ± 10.9 minutes for 100%ON. Regression modeling suggested that pain relief was weighted as more than twice as influential as charging in preference for reduced %PD. CONCLUSIONS: This prospective study suggests that 10-kHz SCS therapy with PD may be successfully used in a large majority of 10-kHz SCS responders, maintaining efficacy while reducing device charging time by nearly two thirds.

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.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group.

BACKGROUND: The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial. METHODS: In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4-5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement. RESULTS: Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation. CONCLUSIONS: Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

The Use of Contrast Agents in Interventional Pain Procedures: A Multispecialty and Multisociety Practice Advisory on Nephrogenic Systemic Fibrosis, Gadolinium Deposition in the Brain, Encephalopathy After Unintentional Intrathecal Gadolinium Injection, and Hypersensitivity Reactions.

This Practice Advisory presents a comprehensive and evidence-based set of position statements and recommendations for the use of contrast media in interventional pain procedures. The advisory was established by an international panel of experts under the auspices of 11 multinational and multispecialty organizations based on a comprehensive review of the literature up to December 31, 2019. The advisory discusses the risks of using gadolinium-based contrast agents. These include nephrogenic systemic fibrosis, gadolinium brain deposition/retention, and encephalopathy and death after an unintentional intrathecal gadolinium injection. The advisory provides recommendations on the selection of a specific gadolinium-based contrast agent in patients with renal insufficiency, those who had multiple gadolinium-enhanced magnetic resonance imaging examinations, and in cases of paraspinal injections. Additionally, recommendations are made for patients who have a history of mild, moderate, or severe hypersensitivity reactions to contrast medium.

Long-Term Efficacy of a Novel Spinal Cord Stimulation Clinical Workflow Using Kilohertz Stimulation: Twelve-Month Results From the Vectors Study.

BACKGROUND AND OBJECTIVES: Multiple variables play a role in spinal cord stimulation (SCS) treatment outcomes, including patient anatomy, pain pattern, lead location, stimulation parameters, and so on. A wide range of stimulation parameters are considered safe and on-label, and as a result a growing number of new frequencies and frequency-combinations are being incorporated into standard practice. A standardized approach to therapy delivery may provide more consistent outcomes for more patients. The Vectors study evaluated whether there is significant sustained improvement in pain and functional outcomes when therapy is delivered using a standardized approach. MATERIALS AND METHODS: Vectors, a post-market, single-arm study evaluated the safety and efficacy of SCS with an implantable neurostimulator starting with 1 kHz stimulation, targeting the T9-T10 disc space following paresthesia mapping. Subjects with chronic intractable low back and leg pain (visual analogue scale [VAS] ≥ 50 mm) were enrolled. The primary endpoint was change in overall pain (VAS) at the three-month visit compared to baseline. Subjects were followed through 12 months. Secondary endpoints included changes in low back and leg pain, quality of life (European Quality of Life - Five Dimensions, EQ-5D-5L), disability (Oswestry Disability Index, ODI), individual subject goals, and subject satisfaction. RESULTS: There was a significant reduction in overall pain (VAS; 45.4 mm) through the three-month visit, which was sustained through 12 months. At 12 months, 79% of subjects had ≥50% improvement in at least one pain domain (overall, lowback or leg) with 85% of subjects reporting therapy satisfaction. There was a decrease in disability and an improvement in quality of life with 70% of subjects achieving a personal activity goal by the three-month visit. CONCLUSIONS: Long-term pain relief and improvement in quality of life and function were achieved when following a standardized workflow. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03345472.

Twelve-Month results from multicenter, open-label, randomized controlled clinical trial comparing differential target multiplexed spinal cord stimulation and traditional spinal cord stimulation in subjects with chronic intractable back pain and leg pain.

BACKGROUND: Spinal cord stimulation (SCS) is a well-established treatment for chronic intractable pain of the trunk and/or limbs; however, low back pain (LBP) is difficult to treat using traditional SCS. Differential Target Multiplexed spinal cord stimulation (DTM SCS) is an advanced approach inspired from animal studies demonstrating improved pain-related behavior and pain-relevant biological processes. OBJECTIVE: The purpose of this study was to compare the effectiveness of DTM SCS and traditional SCS in treating chronic LBP and leg pain (LP). METHODS: This prospective, postmarket randomized controlled trial compared DTM SCS to traditional SCS in patients with chronic LBP and LP. Primary end point was LBP responder rate (percentage of subjects with ≥ 50% relief) at 3 months. Noninferiority and superiority were assessed. Other outcomes included mean change in back and leg pain, responder rates, disability, global health, satisfaction, and safety profile throughout the 12-month follow-up. RESULTS: One hundred twenty-eight subjects were randomized across 12 centers (67 DTM SCS and 61 traditional SCS). Of the 94 patients implanted, 46 subjects in each group completed the 3-month assessment. LBP responder rate of 80.1% with DTM SCS was superior to 51.2% with traditional SCS (p = 0.0010). Mean LBP reduction (5.36 cm) with DTM SCS was greater than reduction (3.37 cm) with traditional SCS (p < 0.0001). These results were sustained at 6 months and 12 months. Safety profiles were similar between treatment groups. CONCLUSION: Superiority of DTM SCS compared with traditional SCS for chronic LBP was demonstrated. Clinical improvements provided by DTM SCS were sustained over 12 months and are expected to significantly impact the management of chronic LBP.

A Systematic Literature Review of Dorsal Root Ganglion Neurostimulation for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of dorsal root ganglion (DRG) stimulation for pain. DESIGN: Grade the evidence for DRG stimulation. METHODS: An international, interdisciplinary work group conducted a literature search for DRG stimulation. Abstracts were reviewed to select studies for grading. General inclusion criteria were prospective trials (randomized controlled trials and observational studies) that were not part of a larger or previously reported group. Excluded studies were retrospective, too small, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: DRG stimulation has Level II evidence (moderate) based upon one high-quality pivotal randomized controlled trial and two lower-quality studies. CONCLUSIONS: Moderate-level evidence supports DRG stimulation for treating chronic focal neuropathic pain and complex regional pain syndrome.

A Systematic Literature Review of Spine Neurostimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of spinal cord stimulation (SCS) for pain. DESIGN: Grade the evidence for SCS. METHODS: An international, interdisciplinary work group conducted literature searches, reviewed abstracts, and selected studies for grading. Inclusion/exclusion criteria included randomized controlled trials (RCTs) of patients with intractable pain of greater than one year's duration. Full studies were graded by two independent reviewers. Excluded studies were retrospective, had small numbers of subjects, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: SCS has Level 1 evidence (strong) for axial back/lumbar radiculopathy or neuralgia (five high-quality RCTs) and complex regional pain syndrome (one high-quality RCT). CONCLUSIONS: High-level evidence supports SCS for treating chronic pain and complex regional pain syndrome. For patients with failed back surgery syndrome, SCS was more effective than reoperation or medical management. New stimulation waveforms and frequencies may provide a greater likelihood of pain relief compared with conventional SCS for patients with axial back pain, with or without radicular pain.

Implementation of the North American Neuromodulation Society Mentorship Program: Recommendations and Survey Results of Participants.

INTRODUCTION: Despite Accredited Counsel of Graduate Medical Education (ACGME) guidance and criteria, there remains variability in training both within each specialty and across the specialties involved in the delivery of neuromodulation. NANS advocates for the efficacious and safe the implementation of neuromodulation and therefore an educational mentoring program with a defined educational platform is needed. MATERIALS AND METHODS: This is a structured, patient centered, and evidence-based approach mentorship program performed more than one year. Mentor/Mentee pairs started in 2015 and data collected were more than a five-year period. RESULTS: There was a 70%-86% response rate on each survey administered. All except one respondent reported that the mentorship program met their previously declared expectations. All the respondents self-reported at least a moderate increase in their knowledge in the field of neuromodulation while 54% of the respondents felt their knowledge in the field to have greatly increased. Most respondents reported an increase in the number of spinal cord stimulator trials and permanent implants performed after the mentorship program. The self-reporting of mentees competencies at the conclusion of the program was statistically significant for higher competency scores in all areas assessed. CONCLUSIONS: The NANs mentorship program met expectations and implementation goals by improving neuromodulation education including covering patient care, delivery, and training topics. The mentoring program provides a structured framework for extending formal physician neuromodulation education outside of direct fellowship training.

Spinal Cord Stimulation Infection Rate and Incremental Annual Expenditures: Results From a United States Payer Database.

OBJECTIVES: Surgical site infections (SSIs) result in significant negative clinical and economic outcomes. The objective of this study is to estimate annual health expenditures associated with spinal cord stimulation (SCS)-related infections. MATERIALS AND METHODS: Data from the Truven MarketScan® databases were used to identify patients with an SCS implant (2009-2014) and a continuous health plan enrollment for at least 12-months before and after implant (index date). Annual expenditures were estimated for patients with a device-related infection vs. those without infection since index date. A generalized linear model estimated annual expenditures attributable to device-related infection. Multivariable expenditure models were conducted separately for patients in initial and replacement groups, controlling for demographics, comorbidities, and clinical characteristics. RESULTS: The study included 6615 patients. Multivariable expenditure models revealed that patients with infection have higher annual expenditures than patients without infection. Estimated incremental annual healthcare expenditures for patients with an infection were $59,716 (95% CI: $48,965-$69,480) for initial implanted patients and $64,833 (95% CI: $37,377-$86,519) for replacement patients. Only 26% of patients who were explanted for infection underwent a reimplant. CONCLUSIONS: These results show the substantial expenditure burden associated with an SCS-related infection. Management of SCS-related infection is important from both clinical and economic standpoints. The economic and clinical data presented here reinforce the need for additional research and strategies for healthcare providers to minimize SCS infections. Future economic research is needed to further define the specific economic cost drivers associated with the extensive expenditure burden.

Spinal Cord Stimulation Infection Rate and Risk Factors: Results From a United States Payer Database.

OBJECTIVE: Surgical site infections can cause negative clinical and economic outcomes. A recent international survey on Spinal Cord Stimulation (SCS) infection control practices demonstrated low compliance with evidence-based guidelines. This study defines infection rate for SCS implants and identifies infection risk factors. MATERIALS AND METHODS: A retrospective analysis of the MarketScan® Databases identified patients with SCS implant (2009-2014) and continuous health plan enrollment for ≥12-months (12 m) preimplant. For logistic regression analysis, patients were enrolled for 12 m postimplant. Kaplan-Meier and Cox Proportional Hazard survival analyses assessed time to infection, with infection rate reported at 12 m postimplant. Logistic regression characterized risk factors based on demographics, comorbidities, and clinical characteristics. RESULTS: In the logistic regression (n = 6615), 12 m device-related infection rate was 3.11%. Infection risk factors included peripheral vascular disease (OR, 1.784; 95% CI: 1.011-3.149; p = 0.0457) and infection in 12 m before implant (OR, 1.518; 95% CI: 1.022-2.254; p = 0.0386). The odds of patients experiencing an infection decreased by 3.2% with each additional year of age (OR, 0.968; 95% CI: 0.952-0.984; p < 0.0001). Survival analysis (n = 13,214) identified prior infection (HR, 1.770; 95% CI: 1.342-2.336; p < 0.0001) as a risk factor. Infection was less likely in older patients (HR, 0.974; 95% CI: 0.962-0.986; p < 0.0001). Expected risk factors including obesity, diabetes, and smoking were not identified as risk factors in this analysis. There was no significant difference between infection rate for initial and replacement implants. CONCLUSIONS: The 3.11% SCS-related infection rate within 12 m of implant emphasizes the need for improved infection control practices. Research is needed to limit SCS infections in younger patients and those with infection history.

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.

The MIST Guidelines: The Lumbar Spinal Stenosis Consensus Group Guidelines for Minimally Invasive Spine Treatment.

BACKGROUND: Lumbar spinal stenosis (LSS) can lead to compression of neural elements and manifest as low back and leg pain. LSS has traditionally been treated with a variety of conservative (pain medications, physical therapy, epidural spinal injections) and invasive (surgical decompression) options. Recently, several minimally invasive procedures have expanded the treatment options. METHODS: The Lumbar Spinal Stenosis Consensus Group convened to evaluate the peer-reviewed literature as the basis for making minimally invasive spine treatment (MIST) recommendations. Eleven consensus points were clearly defined with evidence strength, recommendation grade, and consensus level using U.S. Preventive Services Task Force criteria. The Consensus Group also created a treatment algorithm. Literature searches yielded 9 studies (2 randomized controlled trials [RCTs]; 7 observational studies, 4 prospective and 3 retrospective) of minimally invasive spine treatments, and 1 RCT for spacers. RESULTS: The LSS treatment choice is dependent on the degree of stenosis; spinal or anatomic level; architecture of the stenosis; severity of the symptoms; failed, past, less invasive treatments; previous fusions or other open surgical approaches; and patient comorbidities. There is Level I evidence for percutaneous image-guided lumbar decompression as superior to lumbar epidural steroid injection, and 1 RCT supported spacer use in a noninferiority study comparing 2 spacer products currently available. CONCLUSIONS: MISTs should be used in a judicious and algorithmic fashion to treat LSS, based on the evidence of efficacy and safety in the peer-reviewed literature. The MIST Consensus Group recommend that these procedures be used in a multimodal fashion as part of an evidence-based decision algorithm.

Association of Opioid Usage with Spinal Cord Stimulation Outcomes.

Study Design: Observational study using insurance claims. Objective: To quantify opioid usage leading up to spinal cord stimulation (SCS) and the potential impact on outcomes of SCS. Setting: SCS is an interventional therapy that often follows opioid usage in the care continuum for chronic pain. Methods: This study identified SCS patients using the Truven Health MarketScan databases from January 2010 to December 2014. The index event was the first occurrence of a permanent SCS implant. Indicators of opioid usage at implant were daily morphine equivalent dose (MED), number of unique pain drug classes, and diagnosis code for opioid abuse. System explant was used as a measure of ineffective SCS therapy. Multivariate logistic regression was used to analyze the effect of pre-implant medications on explants. Results: A total of 5,476 patients (56 ± 14 years; 60% female) were included. SCS system removal occurred in 390 patients (7.1%) in the year after implant. Number of drug classes (odds ratio [OR] = 1.11, P = 0.007) and MED level (5-90 vs < 5 mg/d: OR = 1.32, P = 0.043; ≥90 vs < 5 mg/d: OR = 1.57, P = 0.005) were independently predictive of system explant. Over the year before implant, MED increased in 54% (stayed the same in 21%, decreased in 25%) of patients who continued with SCS and increased in 53% (stayed the same in 20%, decreased in 27%) of explant patients (P = 0.772). Over the year after implant, significantly more patients with continued SCS had an MED decrease (47%) or stayed the same (23%) than before (P < 0.001). Conclusions: Chronic pain patients receive escalating opioid dosage prior to SCS implant, and high-dose opioid usage is associated with an increased risk of explant. Neuromodulation can stabilize or decrease opioid usage. Earlier consideration of SCS before escalated opioid usage has the potential to improve outcomes in complex chronic pain.